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1. After spring, after crops: which alternative hosts for the generalist parasitoid Diaeretiella rapae (Hymenoptera: Braconidae)?

Author: Stéphane A. P. Derocles, Yoann Navasse, Pauline Gardin, Christelle Buchard, Anne Le Ralec, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Rennes Angers, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), This work was supported by the French ‘Ministère de l’Enseignement Supérieur et de la Recherche’ and was founded by the French Research National Agency (PEERLESS project, ANR-12-AGRO-0006)., and ANR-12-AGRO-0006,PEERLESS,Viabilité d'une gestion écologique renforcée de la santé des plantes dans les paysages agricoles(2012)
Subjects: Uncultivated areas, Cover crops, Insect Science, Brassicaceae, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Molecular detection
Abstract: International audience; Generalist aphid parasitoids seem to behave as specialists at the local scale. The temporal pattern of host exploitation by parasitoids is key to understand this result. We investigated the temporal dynamics during twenty-one consecutive months of host exploitation by Diaeretiella rapae (M'Intosh) (Hymenoptera: Braconidae), one of the most generalist aphid parasitoid, in cultivated and uncultivated areas. We applied two complementary approaches: molecular detection of parasitism within living aphids and rearing of aphid mummies collected in Brassicaceae crops and adjacent areas. We built a Maximum Likelihood tree to determine the influence of host plant and aphid species on the genetic structure of D. rapae. We confirmed the existence of a cryptic species developing on Hayhurstia atriplicis (L.) (Hemiptera: Aphididae), but we found no other host-related genetic variation. D. rapae exploited almost exclusively Brevicoryne brassicae (L.) (Hemiptera: Aphididae), a pest of Brassiceae and rarely other hosts. When the crop is absent, D. rapae parasitized B. brassicae on wild Brassicaceae and cover crop instead of alternative aphid host on other plants. These results show the limited role of uncultivated habitats as a reservoir for D. rapae and the interest of wild Brassiceae and cover crops to enhance the control of B. brassicae.
Published: 2023
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2. Effect of the Landscape on Insect Pests and Associated Natural Enemies in Greenhouses Crops: The Strawberry Study Case

Author: Marianne Doehler, Delphine Chauvin, Anne Le Ralec, Émeline Vanespen, Yannick Outreman, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Rennes Angers, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and None
Subjects: insect pests, Insect Science, conservation biological control, [SDE]Environmental Sciences, protected cultivation, natural enemies of pests, strawberry crops, landscape context, crop colonization, diversity
Abstract: International audience; Compared to open-field crops, the influence of the surrounding landscape on insect diversity in greenhouse crops has been poorly studied. Due to growing evidence of insect influx in greenhouses, identifying the landscape properties influencing the protected crop colonization by insect pests and their natural enemies would promote the improvement of both pest prevention and conservation biological control methods. Here, we present a field study on the effect of the surrounding landscape on the colonization of greenhouse crops by insect pests and associated natural enemies. By monitoring 32 greenhouse strawberry crops in the South West of France, we surveyed crop colonization by four insect pests and four natural enemy groups over two cultivation periods. Our results showed that the landscape structure and composition could have contrasting effects on insect colonization of greenhouse crops so there could be species-specific effects and not general ones. While the degree of openness of greenhouses and the pest management practices modulated insect diversity marginally, we also showed that seasonality represented a key factor in insect crop colonization. The various responses of insect pests and natural enemy groups to the landscape support the idea that pest management methods must involve the surrounding environment.
Published: 2023
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3. Can biological control be a strategy to control vector‐borne plant viruses?

Author: Sacha Roudine, Cécile Le Lann, Sophie Bouvaine, Anne Le Ralec, Joan van Baaren, Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Natural Resources Institute [Chatham], University of Greenwich, and PLANTSERV
Subjects: Ecology, [SDV.SA.AGRO]Life Sciences [q-bio]/Agricultural sciences/Agronomy, Plant Science, Non-persistently transmitted viruses, parasitoids, [SDV.BV.PEP]Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy, Predators, Persistently transmitted viruses, Insect Science, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Virus outbreaks, Conservation biological control, Agronomy and Crop Science, Ecology, Evolution, Behavior and Systematics
Abstract: International audience; Plant viruses transmitted by vector pests are one of the most important worldwide threats to global food production and security. Biological control strategies to enhance natural enemies (parasitoids and predators) have mainly focused on their ability to reduce pest density. In contrast, few studies have examined how natural enemies affect the spread and the incidence of viruses in a crop, although those results could be used as levers for a more sustainable management of viral diseases. Vector-borne plant viruses can be classified in three categories based on their transmission mode: non-persistently transmit- ted viruses, semi-persistently transmitted viruses and persistently transmitted viruses, whereas vector density, fitness and movement were identified as main drivers of virus spread in a crop, their relative contributions to virus epidemiology may also depend on both the transmission mode and the presence of natural enemies. The first part of the review focuses on virus transmission dynamics in relation to vector activity and density. Because we identify different patterns for each type of plant viruses, control strategies that lead to changes in vector traits, should be adapted to the targeted virus. However, biological control of insect vectors has been rarely adapted to the mode of transmission of the target virus. Thus, the last part of the review explores the conditions required for natural enemies (parasitoids and predators) to prevent epidemics outbreaks of each type of plant viruses. Briefly, if combined with other practices, biological control of vectors to keep virus incidence below the economic threshold is a promising approach for persistently transmitted viruses but might be more difficult to achieve with non-persistently transmitted viruses and semi-persistently transmitted viruses.
Published: 2023
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4. Biocontrôle et macro-organismes: enjeux et réalité

Author: Ris, N., Borowiec, Nicolas, Bout, Alexandre, Debelle, Allan, Fellous, Simon, Le Ralec, Anne, Moquet, Laura, Ogier, Jean-Claude, Rode, Nicolas Olivier, van Oudenhove, Louise, Fauvergue, Xavier, Institut Sophia Agrobiotech (ISA), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Côte d'Azur (UCA), Diversité, Génomes & Interactions Microorganismes - Insectes [Montpellier] (DGIMI), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université de Montpellier (UM), Centre de Biologie pour la Gestion des Populations (UMR CBGP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Montpellier (UM), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Rennes Angers, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Peuplements végétaux et bioagresseurs en milieu tropical (UMR PVBMT), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Université de La Réunion (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Département Systèmes Biologiques (Cirad-BIOS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), and Astruc, Suzette
Subjects: [SDE] Environmental Sciences, Invertébrés, Auxiliaires, Réglementation, [SDE]Environmental Sciences, Prédateurs, Génétique, Lutte biologique, Parasitoïdes, Zootechnie
Abstract: International audience; Contexte: Il existe une diversité de stratégies de biocontrôle faisant appel aux macro-organismes, qu'elles soient pratiquées depuis longtemps en France, plus récemment implantées, voire encore prospectives. enjeux: Il est possible de définir un cadre de réflexion commun à l'ensemble de ces stratégies autour d'enjeux de recherche et développement : réglementation, zootechnie, amélioration génétique, efficacité au champ et risques éventuels. Quatre dynamiques sont susceptibles d'apporter un nouvel élan au biocontrôle à l'aide de macroorganismes : – la convergence entre santé des plantes et santé humaine autour de stratégies communes ; – la convergence entre biocontrôle et production d'insectes comestibles autour d'enjeux communs ; – la complémentarité entre les stratégies interventionnistes utilisant les macro-organismes et la lutte biologique par conservation ; – la nécessaire réflexion concernant de nouvelles organisations économiques et sociales.
Published: 2022

5. Biological control at work: demonstrating the complementary effects of natural enemies on two contrasting pests and the damage they cause

Author: Anne-Marie Cortesero, Xavier Mesmin, Julien Raitif, Vincent Faloya, Pauline Gardin, Anne Le Ralec, Loïc Daniel, Marie Vincent, Marion Maret, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Rennes Angers, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), 0461/ COH14000/00001042, Région Bretagne, 2016 0190, Chaire AEI, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: 0106 biological sciences, Intraguild predation, Natural pest control, Ground dwelling predators, Biological pest control, [SDV.SA.AGRO]Life Sciences [q-bio]/Agricultural sciences/Agronomy, Context (language use), 010603 evolutionary biology, 01 natural sciences, Predation, [SDV.SA.STA]Life Sciences [q-bio]/Agricultural sciences/Sciences and technics of agriculture, 2. Zero hunger, biology, Ecology, business.industry, Pest control, 15. Life on land, biology.organism_classification, 010602 entomology, Damage, Brevicoryne brassicae, Parasitism, Biological control, PEST analysis, business, Agronomy and Crop Science, Delia radicum, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract: International audience; Natural pest control is a significant service supporting agricultural production. However, the relative contribution of several functional groups of natural enemies to natural pest control is unknown for many crop-pest systems. Furthermore, the output of this regulation in terms of damage reduction is rarely assessed. In this study, based on three field experiments, we quantified the effect of ground dwelling predators and parasitoids on two functional groups of broccoli pests. Relying on physical exclusion, we showed that ground dwelling predators significantly lowered the abundance of both the cabbage root fly (Delia radicum) and aphids (Brevicoryne brassicae and Myzus persicae). Ground dwelling predators made a significant contribution to natural pest control, as they lowered pest populations by 37% on average. Parasitoids suppressed 22% of pest populations. Our results suggest that intraguild predation was not an issue since ground dwelling predators did not have a negative impact on the level of natural pest control by parasitoids. Finally, early predation by ground dwelling predators on the cabbage root fly, the most harmful pest in this study, reduced damage in a highly infested context, meaning that natural pest control can effectively support crop production. These results strongly suggest that agricultural practices limiting soil disturbances or even favoring ground dwelling predator overwintering or colonization could lead to fewer damage and losses for farmers. Keywords Natural pest control • Biological control • Intraguild predation • Damage • Ground dwelling predators • Parasitism Key message • We compared the efficiency of two groups of natural enemies on natural pest control. • Two contrasted types of pests, the cabbage root fly and aphids, were studied. • Early generalists and late specialists removed 37 and 22% of pest populations, respectively. • For the cabbage root fly, early ground dwelling predators were key to biological control. • Natural control of the cabbage root fly reduced damage to the crop by 26%.
Published: 2022
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6. Biocontrôle et macro-organismes: panorama

Author: Ris, N., Borowiec, Nicolas, Bout, Alexandre, Debelle, Allan, Fellous, Simon, Le Ralec, Anne, Moquet, Laura, Ogier, Jean-Claude, Rode, Nicolas Olivier, van Oudenhove, Louise, Fauvergue, Xavier, Astruc, Suzette, Institut Sophia Agrobiotech (ISA), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Côte d'Azur (UCA), Diversité, Génomes & Interactions Microorganismes - Insectes [Montpellier] (DGIMI), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université de Montpellier (UM), Centre de Biologie pour la Gestion des Populations (UMR CBGP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Montpellier, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Montpellier (UM), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Rennes Angers, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Peuplements végétaux et bioagresseurs en milieu tropical (UMR PVBMT), and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-Université de La Réunion (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: [SDE] Environmental Sciences, Invertébrés, Auxiliaires, [SDE]Environmental Sciences, Prédateurs, Lutte biologique, Parasitoïdes
Abstract: International audience; Contexte : Malgré des besoins toujours plus pressants de trouver des alternatives aux produits phytopharmaceutiques, force est de constater que le secteur des macro-organismes de biocontrôle peine à se généraliser dans la pratique et, avant tout, à s'imposer dans l'esprit des parties intéressées : les utilisateurs finaux (les agriculteurs), les conseillers techniques, mais également les politiques et les financeurs. Stratégies de lutte : La régulation des bioagresseurs peut se réaliser en favorisant les individus déjà présents dans ou aux alentours des parcelles cultivées : c'est ce que l'on appelle la lutte biologique par conservation. Elle peut également se faire en introduisant certains auxiliaires délibérément dans les parcelles cultivées (acclimatation, augmentation, lutte autocide). Cet article présente les stratégies de biocontrôle à l'aide de macro-organismes (essentiellement des insectes, acariens ou nématodes entomopathogènes), qu'elles soient pratiquées depuis longtemps en France, plus récemment implantées, voire encore prospectives.
Published: 2022

7. Third and fourth trophic level composition shift in an aphid-parasitoid-hyperparasitoid food web limits aphid control in an intercropping system

Author: Estelle Postic, Joan van Baaren, Christelle Buchard, Stéphanie Llopis, Franck Duval, Emma Jeavons, Cécile Le Lann, Anne Le Ralec, Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Fondation Yves Rocher, Institut de France, LTSER Zone Atelier Armorique (LTSER), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro Rennes Angers, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), This study was funded by the ANRT (Association Nationale de la Recherche et de la Technologie), the company Yves Rocher and the FLEUR project (APR-PSPE Contribuer à l'essor du biocontrôle)., Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), LTSER-FR Zone Atelier Armorique, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: 0106 biological sciences, Biological pest control, biological control, 010603 evolutionary biology, 01 natural sciences, Parasitoid, functional community composition, Entomophagous parasite, Trophic level, alternative host, 2. Zero hunger, Aphid, Ecology, biology, intercrop, Intercropping, 15. Life on land, biology.organism_classification, cereal crop, Food web, 010602 entomology, Agronomy, Composition (visual arts), [SDE.BE]Environmental Sciences/Biodiversity and Ecology, hyperparasitism, leguminous crop
Abstract: International audience; Understanding how resource diversification affects ecological interactions, food web structure and ecosystem functioning is essential in both fundamental and applied ecology. While plant diversification strategies (either in-field or around-field) are often proposed in agricultural landscapes as practices to improve the biological control of herbivores by natural enemies, results remain variable and unsure. Here, we studied the effect of an in-field diversification practice (the intercropping of leguminous crops within cereal fields, an increasingly common practice but with inconsistent results on biological control) on cereal aphid control and the structure of a cereal aphid-parasitoid-hyperparasitoid food web for 2 years. We report that aphid control was not increased in mixed fields, nor was cereal parasitoid diversity and food web complexity. Nevertheless, the provision of alternative hosts in mixed fields led to a functional community composition shift, favouring generalist parasitoid species over specialist ones. Moreover, we observed a higher hyperparasitism rate in mixed fields, suggesting that secondary parasitoids were favoured by alternative resources, which may have disrupted aphid control by primary parasitoids. Synthesis and applications. This study demonstrates that parasitoid community composition shift and increased top-down control by the fourth trophic level can impact parasitoid efficiency to control herbivores. These results highlight the necessity to study fine-scale mechanisms within food webs to be able to set up efficient methods to support biodiversity and associated ecosystem services in agricultural landscapes.
Published: 2022
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8. Biocontrôle et macro-organismes : panorama. De la lutte biologique par acclimatation à la technique de l'insecte incompatible, les stratégies de biocontrôle faisant appel aux macro-organismes se diversifient

Author: Ris, Nicolas, Borowiec, Nicolas, Bout, Alexandre, Debellé, Frédéric, Fellous, Simon, Le Ralec, Anne, Moquet, Laura, Ogier, Jean-Claude, Rode, Nicolas-Olivier, Van Oudenhove, Louise, and Fauvergue, Xavier
Subjects: Invertébré, Parasitoïde, H10 - Ravageurs des plantes, Lutte biologique, Prédateur, Agent de lutte biologique, Lutte biologique contre les ravageurs
Abstract: Contexte : Malgré des be- soins toujours plus pressants de trouver des alternatives aux produits phytopharmaceutiques, force est de constater que le secteur des macro-organismes de biocontrôle peine à se généraliser dans la pratique et, avant tout, à s'imposer dans l'esprit des parties intéressées : les utilisateurs finaux (les agriculteurs), les conseillers techniques, mais également les politiques et les financeurs. Stratégies de lutte : La régulation des bioagresseurs peut se réaliser en favorisant les individus déjà présents dans ou aux alentours des parcelles cultivées : c'est ce que l'on appelle la lutte biologique par conservation. Elle peut également se faire en introduisant certains auxiliaires délibérément dans les parcelles cultivées (acclimatation, augmentation, lutte autocide). Cet article présente les stratégies de biocontrôle à l'aide de macro-organismes (essentiellement des insectes, acariens ou nématodes entomopathogènes), qu'elles soient pratiquées depuis longtemps en France, plus récemment implantées, voire encore prospectives.
Published: 2022

9. Genetics of wild and mass-reared populations of a generalist aphid parasitoid and improvement of biological control

Author: Postic, Estelle, Outreman, Yannick, Derocles, Stéphane, Granado, Caroline, Le Ralec, Anne, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), AOPn Fraises de France, AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), ANRT, GIS Piclég, and 30001445), AFB
Subjects: Heredity, Plant Science, Plant Genetics, Medicago, Flowering Plants, Phylogeny, Principal Component Analysis, Ecology, Eukaryota, Discriminant Analysis, food and beverages, Agriculture, Fabaceae, Plants, Legumes, Mitochondria, Insects, Genetic Mapping, Medicine, Research Article, Arthropoda, Ecological Metrics, Science, Crops, Fragaria, Host-Parasite Interactions, Electron Transport Complex IV, Genetics, Animals, Pest Control, Biological, Crop Genetics, Evolutionary Biology, [SDV.GEN.GPO]Life Sciences [q-bio]/Genetics/Populations and Evolution [q-bio.PE], Population Biology, Ecology and Environmental Sciences, fungi, Organisms, Biology and Life Sciences, Genetic Variation, Species Diversity, Invertebrates, Genetics, Population, Haplotypes, Aphids, Pest Control, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Zoology, Entomology, Population Genetics, Crop Science, Microsatellite Repeats
Abstract: International audience; Due to their ability to parasitize various insect species, generalist parasitoids are widely used as biological control agents. They can be mass-reared and released in agroecosystems to control several pest species in various crops. However, the existence of genetic differentiation among populations of generalist parasitoid species is increasingly recognized and this can be associated with an adaptation to local conditions or to a reduced range of host species. Moreover, constraints of mass-rearing conditions can alter genetic variation within parasitoid populations released. These features could be associated with a reduced efficiency of the control of targeted pest species. Here, we focused on strawberry greenhouses where the control of aphids with the generalist parasitoid Aphidius ervi appears to be inefficient. We investigated whether this inefficiency may have both genetic and ecological bases comparing wild and commercial populations of A . ervi . We used two complementary genetic approaches: one based on the mitochondrial marker COI and one based on microsatellite markers. COI analysis showed a genetic differentiation within the A . ervi species, but the structure was neither associated with the commercial/wild status nor with host species factors. On the other hand, using microsatellite markers, we showed a genetic differentiation between commercial and wild A . ervi populations associated with a loss of genetic diversity within the mass-reared populations. Our ecological genetics study may potentially explain the weak efficiency of biological control of aphids in protected strawberry crops and enable to provide some insights to improve biological control.
Published: 2021
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10. Variable impacts of prevalent bacterial symbionts on a parasitoid used to control aphid pests of protected crops

Author: Estelle Postic, Christelle Buchard, Anne Le Ralec, Yannick Outreman, Caroline Granado, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), AOPn Fraises de France, Debreceni Egyetem, 30001445, Genome Institute of Singapore, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: 0106 biological sciences, Hamiltonella defensa, Biological pest control, Aphidius ervi, Zoology, Parasitism, 01 natural sciences, Parasitoid, Aphid, biology, Macrosiphum euphorbiae, Infection dynamics, fungi, food and beverages, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, 010602 entomology, Rhodobium porosum, Protective symbioses, Insect Science, Inundative biological control, PEST analysis, Agronomy and Crop Science, 010606 plant biology & botany, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract: International audience; The ecological role of bacterial symbionts associated with insects is increasingly recognized. Notably, aphids are known to harbour facultative bacterial symbionts that influence their phenotypes like conferring a protection against natural enemies. The most well-known Gamma-Proteobacteria Hamiltonella defensa can provide a defence against hymenopteran parasitoids to their aphid hosts. Aphidiine parasitoids are broadly used as biological control agents in inundative releases against aphids of various greenhouse crops so that defensive symbionts can potentially compromise efficiency of the released parasitoids. Here, we first measured the prevalence and spatiotemporal dynamics of bacterial symbionts infecting eight aphid species colonizing protected strawberry crops in France. Considering the three major aphid pest species of strawberry crops (Acyrthosiphon malvae (Mosley), Macrosiphum euphorbiae (Thomas) and Rhodobium porosum (Sanderson)), we then estimated their possible effects on protection against Aphidius ervi (Haliday), a parasitoid species currently used as a biological control agent. Both symbiotic composition and symbiont prevalences highly differed between aphid species. In the three dominant aphid species, many individuals were single infected or co-infected with H. defensa and Regiella insecticola. Prevalences of these bacterial symbionts highly varied across French regions. Parasitism experiments showed that infection with R. insecticola did not provide any protection against parasitoids while infection with H. defensa would be associated with a strong reduction of parasitism in A. malvae only. These results are valuable to understand the implications of defensive symbionts in the effectiveness of biological control.
Published: 2020
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11. Influence of soil tillage on natural regulation of the cabbage root fly Delia radicum in brassicaceous crops

Author: Anne-Marie Cortesero, Xavier Mesmin, Anne Le Ralec, Loïc Daniel, Manuel Plantegenest, Vincent Faloya, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), 0461/COH14000/00001042, Région Bretagne, 2016 0190, Chaire AEI, Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
Subjects: 0106 biological sciences, Ground dwelling predators, 010603 evolutionary biology, 01 natural sciences, Predation, [SDV.SA.STA]Life Sciences [q-bio]/Agricultural sciences/Sciences and technics of agriculture, Predator, Pest regulation service, 2. Zero hunger, Ecology, biology, business.industry, Cabbage root, fungi, Pest control, food and beverages, 04 agricultural and veterinary sciences, biology.organism_classification, Crop protection, fly, Tillage, Agronomy, Disturbance (ecology), 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, Animal Science and Zoology, PEST analysis, business, Agronomy and Crop Science, Delia radicum
Abstract: International audience; Ground dwelling predators provide regulation services of several insect pests. Enhancing these services may be a step toward integrated crop protection. Many studies have shown that soil tillage is deleterious to ground dwelling predators but pest regulation processes and services have rarely been measured. We performed an experiment to study whether simplifying soil tillage before the establishment of spring broccoli enhanced ground dwelling predator populations and the control they provide on Delia radicum. The direct effect of tillage on arthropods was assessed by comparing their emergence rates in plots differing in soil tillage management. The natural regulation service was assessed by comparing a control and an exclusion treatment in which predators were removed. The effect of soil tillage on carabids, spiders and staphylinids did not match the gradient of disturbance induced by tillage treatments. Tillage did not appear to affect the predators that likely contribute to D. radicum regulation. Consistently, the number of pests suppressed and the root injuries were unaffected by tillage treatments. The main deleterious effect of soil tillage was on the emergence of those carabid species that overwinter partly as larvae, suggesting that spring tillage could affect pest control in the following crops.
Published: 2020
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12. Variations in community assemblages and trophic networks of aphids and parasitoids in protected crops

Author: Anne Le Ralec, Estelle Postic, Yannick Outreman, Caroline Granado, Christelle Buchard, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), AOPn Fraises de France, 30001445, Agence française pour la biodiversité, GIS Piclég, ARNT, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: 0106 biological sciences, [SDV]Life Sciences [q-bio], Biological pest control, [SDV.SA.AGRO]Life Sciences [q-bio]/Agricultural sciences/Agronomy, biological control, Biology, natural enemies, 010603 evolutionary biology, 01 natural sciences, lcsh:QH540-549.5, Natural enemies, Ecology, Evolution, Behavior and Systematics, Trophic level, 2. Zero hunger, Ecology, insect pests, fungi, food and beverages, 15. Life on land, biochemical phenomena, metabolism, and nutrition, spatiotemporal variation, 010602 entomology, 13. Climate action, direct and indirect interactions, strawberry crops, lcsh:Ecology
Abstract: International audience; Greenhouse crops are thought to be simplified ecosystems because they often consist of mono-cultures that are relatively isolated from their environment. However, insect pests are still able to colonize these protected crops, which threaten their yields. Similarly, natural enemies of pests may be able to colonize greenhouses, providing a form of natural biological pest control. Protected strawberry crops are grown in several types of greenhouses that vary in their degree of openness. Crops often suffer from aphid outbreaks, which can be partly controlled by insect parasitoids immigrating from the surrounding environment. We investigated variations over space and time in both the aphid and parasitoid community diversity and species assemblages associated with protected strawberry crops. We sampled aphids and parasitoids in five regions of France in the spring and summer of two successive years. Despite the relative isolation of these protected crops, we identified a high aphid species richness in them, even at the greenhouse scale. Aphid community composition varied with spatial and temporal factors, but the species assemblages present were mostly determined by local factors. Parasitoid communities were mostly similar among the studied regions, but varied between seasons, with this temporal variation being related to changes in aphid species composition. The study of trophic interactions occurring between aphids and parasitoids allowed the most prevalent and efficient parasitoid species to be identified. The structures of food webs strongly varied in time and space, compromising any prediction of "natural" biological control. We also highlighted ecological factors that can disrupt aphid biological control, such as the occurrence of hyperparasitism or the possibility of apparent mutualism between aphid species. Finally, we showed that the degree of openness of greenhouses influenced both the aphid communities and the hyperparasitism rates in them. These results provide valuable information to improve aphid biological control in protected crops.
Published: 2020
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13. 'Generalist' Aphid Parasitoids Behave as Specialists at the Agroecosystem Scale

Author: Yoann Navasse, Anne Le Ralec, Christelle Buchard, Manuel Plantegenest, Stephane A. P. Derocles, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), ANR-12-AGRO-0006, Agence Nationale de la Recherche, ANR-12-AGRO-0006,PEERLESS,Viabilité d'une gestion écologique renforcée de la santé des plantes dans les paysages agricoles(2012), ANR-12-BS07-0009,SCATE,Addition Conjuguée Asymétrique Sequentielle 1,6/1,4 et piégeages d'énolates: Applications en synthèse de produits naturels(2012), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), AGROCAMPUS OUEST-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA)
Subjects: 0106 biological sciences, [SDV.BV.ECO]Life Sciences [q-bio]/Vegetal Biology/domain_sdv.bv.eco, specialist, agroecosystem, host range, Biology, Generalist and specialist species, 010603 evolutionary biology, 01 natural sciences, Article, Parasitoid, cytochrome c oxidase I, 03 medical and health sciences, [SDV.SA.STA]Life Sciences [q-bio]/Agricultural sciences/Sciences and technics of agriculture, generalist, maximum likelihood, Aphidiinae, parasitoid, 030304 developmental biology, Trophic level, trophic interactions, 0303 health sciences, Aphid, Obligate, Host (biology), Ecology, fungi, food and beverages, 15. Life on land, biology.organism_classification, [SDV.BA.ZI]Life Sciences [q-bio]/Animal biology/Invertebrate Zoology, aphid, Insect Science, PEST analysis, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract: International audience; The degree of trophic specialization of interacting organisms impacts on the structure of ecological networks and has consequences for the regulation of crop pests. However, it remains difficult to assess in the case of parasitoids. Host ranges are often established by listing host records from various years and geographic areas in the literature. Here, we compared the actual hosts exploited at a local farm-scale by aphid parasitoids (Hymenoptera: Aphidiinae), to the available species listed as hosts for each parasitoid species. We sampled aphids and their parasitoids in cultivated and uncultivated areas in an experimental farm from April to November 2014 and thereafter used DNA-based data to determine whether a differentiation in sequences existed. Twenty-nine parasitoid species were found on 47 potential aphid hosts. Our results showed that the great majority of the parasitoid tested used fewer host species than expected according to data published in the literature and parasitized a limited number of hosts even when other potential hosts were available in the environment. Moreover, individuals of the most generalist species differed in their DNA sequences, according to the aphid species and/or the host plant species. At a local scale, only obligate or facultative specialist aphid parasitoids were detected. Local specialization has to be considered when implementing the use of such parasitoids in pest regulation within agroecosystems.
Published: 2019
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14. Chapitre 6. Caractéristiques écologiques des organismes impliqués dans la régulation naturelle et la pollinisation

Author: Violette Le Féon, Yann Tricault, Christophe Le May, and Anne Le Ralec
Subjects: Biology
Published: 2019
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15. Towards the prediction of levels of infestation of Acyrthosyphon pisum in pea-wheat mixtures

Author: David Camilo Corrales Munoz, Marie-Hélène Robin, Bruno Jaloux, Cécile Le Lann, Anne Le Ralec, Martin Luquet, Yann Tricault, Juan Cancino Sanchez, Jean-Noël Aubertot, AGroécologie, Innovations, teRritoires (AGIR), Institut National de la Recherche Agronomique (INRA)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Université de Toulouse (UT)-Université de Toulouse (UT), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), and Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)
Subjects: [SDV]Life Sciences [q-bio], [SDE]Environmental Sciences, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, ComputingMilieux_MISCELLANEOUS
Abstract: Session 17. Tools to design, manage and monitor diversified systems from the field to the landscape levels; International audience
Published: 2019

16. Assessing the relationship between pest density and plant damage: a case study with the belowground herbivore Delia radicum (Diptera: Anthomyiidae) on broccoli

Author: Vincent Faloya, Vianney Estorgues, Marie Vincent, Yann Tricault, Anne Le Ralec, Loïc Daniel, Anne-Marie Cortesero, Xavier Mesmin, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Chambre Régionale d'Agriculture de Bretagne, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), 0461/COH14000/00001042, Région Bretagne, P00315, GIS PIClég, 2016 0190, Chaire AEI, Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, AGROCAMPUS OUEST-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA)
Subjects: 0106 biological sciences, 0301 basic medicine, Crop losses, Population, medicine.disease_cause, 01 natural sciences, 03 medical and health sciences, Anthomyiidae, Infestation, medicine, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, education, 2. Zero hunger, Herbivore, education.field_of_study, Damage Plant compensation, biology, fungi, 31 Crop losses, food and beverages, 15. Life on land, plant injury, biology.organism_classification, Crop protection, [SDV.BV.PEP]Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy, 010602 entomology, 030104 developmental biology, Agronomy, plant traits, Insect Science, Brassica oleracea, PEST analysis, plant compensation, damage, Delia radicum
Abstract: International audience; For many crops, we have poor knowledge about the relationship between pest density and damage. However, investigating pest harmfulness is particularly relevant currently in the search for alternative crop protection strategies that are unlikely to totally suppress pest populations. Here, we assessed the harmfulness of Delia radicum (L.) (Diptera: Anthomyiidae) on broccoli (Brassica oleracea var. italica Plenck). We worked inside insect-proof cages set up in the field with additional pitfall traps to remove ground-dwelling predators. Plants were manually infested with 10 levels of pest density ranging 0–100 individuals per plant, following a natural infestation pattern. Surprisingly, no plants died but almost 100% of the pests introduced died over the course of the experiment. However, all broccoli development and growth traits were negatively correlated with pest density and broccoli head mass at harvest decreased linearly with pest density. The observation over time of development and growth traits showed evidence of plant compensation, suggesting that the head mass of individual plants may have reached similar values if allowed to fully mature. The relationship between pest density and damage, together with forecast models of pest population dynamics could be used to develop decision support tools assessing the relevance of preventative treatments.
Published: 2019
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17. Regulatory potential of parasitoids over Aphis gossypii Glover, 1877 populations (Hemiptera: Aphididae) under semi-arid laboratory conditions

Author: Yannick Outreman, Yamina Guenaoui, Raouf Bensaad, Anne Le Ralec, Université Abdelhamid Ibn Badis de Mostaganem, Université Ziane Achour de Djelfa, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, AGROCAMPUS OUEST-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA)
Subjects: Biological pest control, Lysiphlebus testaceipes, 5 - Ciencias puras y naturales::59 - Zoología [CDU], Climatic conditions, Industrial and Manufacturing Engineering, Parasitoid, Cultivo de patata, Potato fields, Aphis gossypii, Condiciones climáticas, [SDV.SA.STA]Life Sciences [q-bio]/Agricultural sciences/Sciences and technics of agriculture, Aphidius matricariae, Aphid pests, Palabras clave: Plaga de pulgones, Control biológico, Aphid, biology, Aphididae, biology.organism_classification, Hemiptera, Plaga de pulgones, [SDV.BV.PEP]Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy, Horticulture, Biological control, [SDV.EE.IEO]Life Sciences [q-bio]/Ecology, environment/Symbiosis
Abstract: International audience; Potencial regulador de parasitoides sobre poblaciones de Aphis gossypii Glover, 1877 (Hemiptera: Aphididae) en laboratorio, bajo condiciones semiáridas Este estudio tiene como objetivo evaluar el potencial regulador de Lysiphlebus testaceipes y Aphidius matricariae sobre Aphis gossy-pii en condiciones de laboratorio semiáridas. Nuestros resultados mostraron que la longevidad de las hembras de L. testaceipes fue significativamente menor que la de A. matricariae. El porcentaje diario de momificación fue más importante para L. testaceipes que para A. matricariae y disminuyó con la edad de los parasitoides. En general, las tasas de momificación y de emergencia fueron más altas en L. testaceipes. La descendencia de A. matricariae se des-arrolló en menos tiempo que la de L. testaceipes. La proporción sexual no varió respecto a las especies parasitoides. Con nuestros resultados, L. testaceipes fue más efectivo para el control biológico de A. gossypii en patata en agro-ecosistemas semiáridos. Abstract This study aims to evaluate the regulatory potential of Lysiphlebus testaceipes and Aphidius matricariae over Aphis gossypii in semi-arid laboratory conditions. Our results showed that the longevity of L. testaceipes females was significantly lower than A. matricariae ones. The daily mummification rate of aphid was more important for L. testaceipes than for A. matricariae and declined with parasitoids age. Overall, both the mummification rates and the emergence rates were the highest in L. testaceipes. A. matricariae offspring developed in a shorter time compared to L. testaceipes ones. The overall sex ratio did not vary according to parasitoid species. From our results L. testaceipes was more effective for the biological control of A. gossypii on potato in the semi-arid agro-ecosystems.
Published: 2019
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18. Le contrôle biologique passe le test

Author: Mesmin, Xavier, Le Ralec, Anne, Faloya, Vincent, Cortesero, Anne-Marie, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: ComputingMilieux_MISCELLANEOUS, [SDV.BV.PEP]Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy
Abstract: National audience
Published: 2019

19. Caractéristiques écologiques des organismes impliqués dans les processus de régulation naturelle et de pollinisation

Author: Anne Le Ralec, Violette Le Féon, Christophe Le May, Yann Tricault, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Sandrine Petit, Claire Lavigne, and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: [SDE.BE]Environmental Sciences/Biodiversity and Ecology
Abstract: National audience; Ce chapitre synthétise les connaissances autour de la biologie et des traits de vie des différents groupes d’organismes acteurs des processus de régulations biologiques, en mettant à la fois l’accent sur les bioagresseurs (plantes adventices, champignons, bactéries, virus, insectes ravageurs) et sur leurs ennemis naturels. Il présente aussi les caractéristiques des différents groupes impliqués dans la pollinisation
Published: 2019

20. Are generalist Aphidiinae (Hym. Braconidae) mostly cryptic species complexes?

Author: Stephane A. P. Derocles, Jean-Yves Rasplus, David H. Lunt, Manuel Plantegenest, Darren M. Evans, Alexia Marie, and Anne Le Ralec
Subjects: 0106 biological sciences, 0301 basic medicine, Aphid, Species complex, Nuclear gene, biology, Host (biology), biology.organism_classification, Generalist and specialist species, 010603 evolutionary biology, 01 natural sciences, 03 medical and health sciences, 030104 developmental biology, Evolutionary biology, Insect Science, Botany, Clade, Aphidiinae, Braconidae, Ecology, Evolution, Behavior and Systematics
Abstract: Aphidiinae are mostly composed of specialist parasitoids and the few species described as generalist are suspected to be composed of cryptic specialists, almost indistinguishable based on morphological characteristics. The use of molecular markers has proven to be a useful tool for revealing cryptic species complexes and here we use seven mitochondrial and nuclear gene fragments to study possible genetic differentiation among seven Aphidiinae generalists. Maximum likelihood (ML) trees and Bayesian Poisson tree processes (bPTP) models were conducted on each gene separately and on the seven genes together. The standard cytochrome c oxidase I barcode region appeared to be the most polymorphic and probably the best marker to reveal putative cryptic species. However, we showed with ML trees and bPTP models that a complementary use of mitochondrial and nuclear genes was the most relevant approach to reliably identify cryptic genetic clades in the Aphidiinae. Overall, most of the analysed generalist morphospecies were shown to be composed of subgroups related to the aphid host, some of them revealed as cryptic species by the species delimitation analysis. Further studies are needed to reveal the generality of this result in Aphidiinae.
Published: 2015
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21. PNAS

Author: Miriam Kishinevsky, Lucie Raymond, Aldo De la Mora, Örjan Östman, Haijun Xiao, Linda J. Thomson, David J. Perović, F. J. Frank van Veen, Richard F. Pywell, Bea Maas, Noelline Tsafack, George E. Heimpel, Ricardo Perez-Alvarez, Fabrice DeClerck, Ben P. Werling, Jennifer B. Wickens, Jean-Pierre Sarthou, Daniel S. Karp, Riccardo Bommarco, Ignazio Graziosi, Pierre Franck, Teja Tscharntke, J.M. Baveco, Carsten F. Dormann, Christof Schüepp, Claire Lavigne, Henrik G. Smith, James O. Eckberg, Sonja Stutz, Heidi Liere, Philippe Menozzi, Julia Saulais, Aaron L. Iverson, Tadashi Miyashita, Megan E. O'Rourke, Diego J. Inclán, Milan Plećaš, Timothy D. Meehan, Felix J.J.A. Bianchi, Michael J. Brewer, Gudrun Schneider, Katja Jacot, Muriel Valantin-Morison, Soroush Parsa, Nicolas Desneux, Lynn S. Adler, Gonzalo Alberto Roman Molina, Yves Carrière, Adrien Rusch, Vesna Gagic, Marco A. Molina-Montenegro, Luis Cayuela, Zsofia Szendrei, Mattias Jonsson, Ariane Chabert, Peter B. Goodell, Ben A. Woodcock, Daniel Paredes, Deborah K. Letourneau, Kaitlin Stack Whitney, Dominic C. Henri, Therese Pluess, Nancy A. Schellhorn, Gregg A. Johnson, Douglas A. Landis, Lorenzo Marini, Matthias Albrecht, Yael Lubin, Eric Bohnenblust, Kevi Mace, Rebecca Chaplin-Kramer, Anne-Marie Cortesero, Mary Centrella, Chris Sargent, Marina Kaiser, Simon G. Potts, Benoit Ricci, Giovanni Tamburini, Audrey Alignier, Filipe Madeira, Wei Zhang, Akira Yoshioka, Berta Caballero-López, Mai van Trinh, Matthew G. E. Mitchell, Eva Diehl, Aleksandar Ćetković, Hazel R. Parry, Daniela Fiedler, Jessica Schäckermann, Matthias Tschumi, Mika Yasuda, Tatyana A. Rand, Anders S. Huseth, Yann Tricault, Geoff M. Gurr, Michael A. Nash, Kris A.G. Wyckhuys, Damie Pak, Heather Grab, Xavier Pons, Klaus Birkhofer, Itai Opatovsky, Manuel Plantegenest, Stephen D. Wratten, Sebaastian Ortiz-Martinez, Joop de Kraker, N. Schmidt, Debissa Lemessa, Michael P.D. Garratt, Tamar Keasar, Lauren Hunt, Tim Diekötter, Viktoria Mader, John D. Herrmann, Alejandro C. Costamagna, Kerri T. Vierling, Luísa G. Carvalheiro, Hisatomo Taki, Thomas Frank, Sandrine Petit, David W. Ragsdale, Holly M. Martinson, Jay A. Rosenheim, Anne Le Ralec, Annie Ouin, Yanhui Lu, Tania N. Kim, Yi Zou, Wopke van der Werf, Victoria J. Wickens, Blas Lavandero, Awraris Getachew, Zachary Hajian-Forooshani, Adam J. Ingrao, Alejandra Martínez-Salinas, David J. Gonthier, Phirun, Ashley E. Larsen, Laura E. Jones, Péter Batáry, Julie A. Peterson, Muhammad Zubair Anjum, Frances S. Sivakoff, Claudio Gratton, Eliana Martínez, Mayura B. Takada, Gina M. Angelella, Tim Luttermoser, Martin H. Entling, Stacy M. Philpott, Matthew E. O'Neal, Jacques Avelino, Russell L. Groves, Joe M. Kaser, Katja Poveda, Emily A. Martin, School of Plant and Environmental Sciences, Institut National de la Recherche Agronomique - INRA (FRANCE), Institut National Polytechnique de Toulouse - INPT (FRANCE), Dynamiques et écologie des paysages agriforestiers (DYNAFOR), École nationale supérieure agronomique de Toulouse [ENSAT]-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Department Science, RS-Research Line Learning (part of LIRS program), National Science Foundation (US), Institut National Polytechnique de Toulouse - Toulouse INP (FRANCE), École nationale supérieure agronomique de Toulouse (ENSAT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, and Karp, Daniel S.
Subjects: 0106 biological sciences, Integrated pest management, Biodiversité et Ecologie, Ecosytem services, Biodiversity, ECOSYSTEM SERVICES, 01 natural sciences, Ecosystem services, [SDV.SA.SF]Life Sciences [q-bio]/Agricultural sciences/Silviculture, forestry, Models, 2. Zero hunger, [SDV.EE]Life Sciences [q-bio]/Ecology, environment, Multidisciplinary, Ecology, Biological Sciences, PE&RC, PNAS Plus, Habitat, Biological control, agroecology, biodiversity, biological control, ecosytem services, natural enemies, Crop and Weed Ecology, Crops, Agricultural, Conservation of Natural Resources, Life on Land, Natural enemies, Crops, Biology, Sustainability Science, 010603 evolutionary biology, Models, Biological, Ecology and Environment, Biodiversity and Ecology, Sylviculture, foresterie, Agroecology, Animals, Ecosystem, Pest Control, Biological, Commentaries, CONFIGURATION, Ecologie, Environnement, Agricultural, Agricultural/growth & development, business.industry, Habitat conservation, Pest control, Farm Systems Ecology Group, 15. Life on land, SIMPLIFICATION, Biological, 010602 entomology, Crops, Agricultural/growth & development, IPM, Species richness, Pest Control, Landscape ecology, business
Abstract: The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies., This work was supported through the National Socio-Environmental Synthesis Center (SESYNC) National Science Foundation Award DBI-1052875 for the project “Evidence and Decision-Support Tools for Controlling Agricultural Pests with Conservation Interventions” organized by D.S.K. and R.C.-K
Published: 2018
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22. Dégâts de géomyze sur maïs analyse des facteurs de risque

Author: Bailly-Maitre, Agnès, Galland, Victor, Valadas, Amelie, Le Ralec, Anne, Kreiter, Serge, Gout, Lilian, Moquet, Michel, Thibord, J.B., Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, Centre de Biologie pour la Gestion des Populations (UMR CBGP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), AgroParisTech, ARVALIS - Institut du végétal [Paris], Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
Subjects: maïs, [SDV]Life Sciences [q-bio], [SDE]Environmental Sciences, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, geomyse, facteurs climatiques, geomyza tripunctata, modèle
Abstract: National audience; Contexte : Les attaques de géomyze, un ravageur du maïs, sont variables d'une année à l'autre, et peuvent être très nuisibles (dans l'ouest de la France en 2016). Face à l'interdiction des outils de lutte efficaces (traitements de semences néonicotinoïdes), des moyens de compréhension et de prévision sont recherchés. Travail : une enquête réalisée en Bretagne a révélé qu'aucun facteur agronomique n'avait influencé les dégâts en 2016, ce qui suggère l'influence des facteurs climatiques annuels. Une recherche de tels facteurs a été réalisée. Résultats : quatre facteurs ont été identifiés, dont trois intervenants avant les semis (dans l'été et l'hiver précédent). Un modèle descriptif et un prototype de modèle prédictif ont été élaborés. Le travail doit continuer.
Published: 2018

23. Brassicacées et contrôle biologique : un levier suffisant pour les protéger ?

Author: Mesmin, Xavier, Le Ralec, Anne, Faloya, Vincent, Cortesero, Anne Marie, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: ComputingMilieux_MISCELLANEOUS, [SDV.BV.PEP]Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy
Abstract: National audience
Published: 2018

24. Evaluation des régulations biologiques dans des systèmes agroécologiques

Author: Ameline, Camille, Le Ralec, Anne, Agroécologie [Dijon], Université de Bourgogne (UB)-Institut National de la Recherche Agronomique (INRA)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-AgroSup Dijon - Institut National Supérieur des Sciences Agronomiques, de l'Alimentation et de l'Environnement, AgroSup Dijon, Petit, S., and EL Mjiyad, Noureddine
Subjects: [SDE] Environmental Sciences, [SDE]Environmental Sciences
Abstract: Engineering school; Les analyses et les conclusions de ce travail d'étudiant n'engagent que la responsabilité de son auteur et non celle d'AGROCAMPUS OUEST Ce document est soumis aux conditions d'utilisation « Paternité-Pas d'Utilisation Commerciale-Pas de Modification 4.
Published: 2018

25. Crop pests and predators exhibit inconsistent responses to surrounding landscape composition

Author: Karp, Daniel S., Chaplin-Kramer, Rebecca, Meehan, Timothy D., Martin, Emily A., DeClerck, Fabrice, Grab, Heather, Gratton, Claudio, Hunt, Lauren, Larsen, Ashley E., Martinez-Salinas, Alejandra, O'Rourke, Megan E., Rusch, Adrien, Poveda, Katja, Jonsson, Mattias, Rosenheim, Jay A., Schellhorn, Nancy A., Tscharntke, Teja, Wratten, Stephen D., Zhang, Wei, Iverson, Aaron L., Adler, Lynn S., Albrecht, Matthias, Alignier, Audrey, Angelella, Gina M., Anjum, Muhammad Zubair, Avelino, Jacques, Batary, Peter, Baveco, Johannes M., Bianchi, Felix J.J.A., Birkhofer, Klaus, Bohnenblust, Eric W., Bommarco, Riccardo, Brewer, Michael J., Caballero-López, Berta, Carrière, Yves, Carvalheiro, Luísa G., Cayuela, Luis, Centrella, Mary, Cetkovic, Aleksandar, Henri, Dominic Charles, Chabert, Ariane, Costamagna, Alejandro C., De la Mora, Aldo, De Kraker, Joop, Desneux, Nicolas, Diehl, Eva, Diekötter, Tim, Dormann, Carsten F., Eckberg, James O., Entling, Martin H., Fiedler, Daniela, Franck, Pierre, van Veen, Frank, Frank, Thomas, Gagic, Vesna, Garratt, Michael P.D., Getachew, Awraris, Gonthier, David J., Goodell, Peter B., Graziosi, Ignazio, Groves, Russell L., Gurr, Geoff M., Hajian-Forooshani, Zachary, Heimpel, George E., Herrmann, John D., Huseth, Anders S., Inclán, Diego J., Ingrao, Adam J., Iv, Phirun, Jacot, Katja, Johnson, Gregg A., Jones, Laura, Kaiser, Marina, Kaser, Joe M., Keasar, Tamar, Kim, Tania N., Kishinevsky, Miriam, Landis, Douglas A., Lavandero, Blas, Lavigne, Claire, Le Ralec, Anne, Lemessa, Debissa, Letourneau, Deborah K., Liere, Heidi, Lu, Yanhui, Lubin, Yael, Luttermoser, Tim, Maas, Bea, Mace, Kevi, Madeira, Felipe, Mader, Viktoria, Cortesero, Anne-Marie, Marini, Lorenzo, Martinez, Eliana, Martinson, Holly M., and Menozzi, Philippe
Subjects: F08 - Systèmes et modes de culture, H10 - Ravageurs des plantes
Abstract: The idea that noncrop habitat enhances pest control and represents a win–win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win–win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.
Published: 2018

26. Ecological specialization in Diaeretiella rapae (Hymenoptera: Braconidae: Aphidiinae) on aphid species from wild and cultivated plants

Author: A. Le Ralec, Y Navasse, Stephane A. P. Derocles, Manuel Plantegenest, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: 0106 biological sciences, Male, Species complex, Hayhurstia atriplicis, Brevicoryne brassicae, agroecosystem, reproductive isolation, Wasps, Biological pest control, host range, 010603 evolutionary biology, 01 natural sciences, Host Specificity, Host-Parasite Interactions, non-cultivated areas, Animals, Aphidiinae, 2. Zero hunger, Aphid, biology, Diaeretiella rapae, Ecology, fungi, food and beverages, General Medicine, 15. Life on land, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, 010602 entomology, Insect Science, Aphids, Hybridization, Genetic, host switching, Female, PEST analysis, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Agronomy and Crop Science, Braconidae
Abstract: Diaeretiella rapae is an aphid parasitoid with potential for use in biological control strategies. However, several recent genetic studies have challenged the long held view that it is a generalist parasitoid. We investigated its ecological specialization and ability to use resources in cultivated and uncultivated areas. Ecological specialization would reduce its ability to exploit the diversity of aphid species, particularly in uncultivated areas, and to control pest aphids. Four D. rapae strains were studied, three reared on pest aphids on Brassicaceae and one strain on a non-pest aphid on Chenopodiaceae. For each strain, we performed host-switching experiments, with a total of six aphid species, five of which D. rapae parasitizes in France. We tested cross-breeding ability between strains to detect potential reproductive isolation linked to aphid host species in D. rapae. The strain reared on non-pest aphids was able to develop on aphid species from both cultivated and uncultivated plants. The strains reared on pest aphids, however, exclusively parasitized aphid species on cultivated Brassicaceae. In addition, reproductive isolation was detected between strains from uncultivated and cultivated plants. Thus, the D. rapae populations examined here appear to be showing ecological specialization or they may even be composed of a complex of cryptic species related to the aphid hosts. The role of Chenopodium album as a reservoir for D. rapae, by providing a habitat for non-pest aphids on which it can feed, appears to be severely limited, and thus its efficiency to maintain local populations of D. rapae in the vicinity of crops is questionable.
Published: 2017
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27. Permanent Genetic Resources added to Molecular Ecology Resources Database 1 April 2013–31 May 2013

Author: Agostini, Cecilia, Albaladejo, R. G., Aparicio, A., Arthofer, Wolfgang, Berrebi, P., Boag, Peter T., Carbone, Ignazio, Conroy, Gabriel C., Cortesero, Anne-Marie, Goncalves, Evonnildo Costa, Costa, Diogo, Couto, Alvarina, De Girolamo, Mirko, Du, Hao, Fu, Shi-Jian, Garrido-Garduño, T., Gettova, L., Gilles, A., Hamoy, Igor Guerreiro, Herrera, C. M., Heussler, Carina, Isidro, Eduardo, Josso, Céline, Krapf, Patrick, Lamont, Robert W., Le Ralec, Anne, Lopes, Susana, Luis, Carla, Luo, Hui, Maheo, Frédérique, Marino, Ilaria A. M., Mieuzet, Lucie, Murray, Brent W., Ogbourne, Steven M., Pallavicini, Alberto, Parejo-Farnés, C., Patarnello, Tomaso, Paty, Chrystelle, Pereira, Carolina, Pinho, Catarina, Pinto, Pablo, Poinsot, Denis, Powell, Adrienne, Putman, Alexander I., Santoro, André, Santos, Sidney, Schlick-Steiner, Birgit C., Scott, Candace, Barbosa, Maria Silvanira, Simkova, A., Simon, Jean-Christophe, Solé-Cava, Antonio, Steiner, Florian M., Sun, Zhengxin, Torboli, Valentina, Tredway, Lane P., de Groot, Peter J. Van Coeverden, Vasconcellos, Anderson, Vázquez-Domínguez, E., Wang, Deng-Qiang, Wang, Yu-Xiang, Wei, Qi-Wei, Zane, Lorenzo, Zhang, Shu-Huan, Department of Biology, Universita degli Studi di Padova, Departamento Biología Vegetal y Ecología, Institute of Ecology, Molecular Ecology Group, University of Innsbruck, Institut des Sciences de l'Evolution de Montpellier (UMR ISEM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Queen's University [Kingston], Department of Plant Pathology, North Carolina State University [Raleigh] (NC State), University of North Carolina System (UNC)-University of North Carolina System (UNC), GeneCology Research Centre, University of the Sunshine Coast, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), Université européenne de Bretagne - European University of Brittany (UEB), Instituto de Ciências Biológicas, Laboratório de Tecnologia Biomolecular, Federal University of Para - Universidade Federal do Para [Belem - Brésil], CIBIO/UP, Centro de Investigação em Biodiversidade e Recursos Genéticos, Universidade do Porto [Porto], Instituto do Mar (IMAR), Department of Oceanography and Fisheries, University of the Azores, Key Laboratory of Freshwater Biodiversity Conservation, Ministry of Agriculture of China, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Laboratory of Evolutionary Physiology and Behaviour, Chongqing Key Laboratory of Animal Biology, Chongqing University, Instituto de Ecología, Departamento de Ecología de la Biodiversidad / Posgrado en Ciencias Biológicas, Universidad National Autonoma de Mexico, Faculty of Science, Department of Botany and Zoology, Masaryk University, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Universidade Federal Rural da Amazônia (UFRA), Instituto de Ciências Biológicas, Laboratório de Genética Humana e Médica, Estación Biológica de Doñana, Spanish National Research Council (CSIC), Fisheries College, Huazhong Agricultural University, Natural Resources and Environmental Studies Institute, University of Northern British Columbia (UNBC), Dipartimento di Scienze della Vita, Laboratorio di Genetica, University of Trieste, Department of Comparative Biomedicine and Food Science, Instituto de Biologia, Laboratório de Biodiversidade Molecular, Universidade Federal Rural do Rio de Janeiro (UFRRJ), Instituto de Ciências Biológicas, Laboratório de Polimorﬁsmo de DNA, Instituto de Ecología, Departamento de Ecología de la Biodiversidad, Università degli Studi di Padova = University of Padua (Unipd), Leopold Franzens Universität Innsbruck - University of Innsbruck, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Montpellier (UM)-Institut de recherche pour le développement [IRD] : UR226-Centre National de la Recherche Scientifique (CNRS), Queen's University [Kingston, Canada], Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, Federal University of Para - Universidade Federal do Pará - UFPA [Belém, Brazil] (UFPA), Universidade do Porto = University of Porto, Masaryk University [Brno] (MUNI), Estación Biológica de Doñana (EBD), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Huazhong Agricultural University [Wuhan] (HZAU), University of Northern British Columbia [Prince George] (UNBC), Università degli studi di Trieste = University of Trieste, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-École pratique des hautes études (EPHE), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Universidade do Porto, Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UMR237-Aix Marseille Université (AMU)-Avignon Université (AU), Cecilia, Agostini, R. G., Albaladejo, A., Aparicio, Wolfgang, Arthofer, P., Berrebi, Peter T., Boag, Ignazio, Carbone, Gabriel C., Conroy, A. M., Cortesero, Evonnildo Costa, Gonçalve, Diogo, Costa, Alvarina, Couto, MIrko De, Girolamo, Hao, Du, Shi Jian, Fu, T., Garrido Garduño, L., Gettová, A., Gille, Igor Guerreiro, Hamoy, C. M., Herrera, Carina, Heussler, Eduardo, Isidro, C., Josso, Patrick, Krapf, Robert W., Lamont, A., Le Ralec, Susana, Lope, Carla, Luí, Hui, Luo, F., Mahéo, Ilaria A. M., Marino, L., Mieuzet, Brent W., Murray, Steven M., Ogbourne, Pallavicini, Alberto, C., Parejo Farné, Tomaso, Patarnello, C., Paty, Carolina, Pereira, Catarina, Pinho, Pablo, Pinto, D., Poinsot, Adrienne, Powell, Alexander I., Putman, André, Santoro, Sidney, Santo, Birgit C., Schlick Steiner, Candace, Scott, Maria Silvanira, Barbosa, A., Šimková, J. C., Simon, Antonio Solé, Cava, Florian M., Steiner, Zhengxin, Sun, Torboli, Valentina, Lane P., Tredway, Peter J., Van Coeverden de Groot, Anderson, Vasconcello, E., Vázquez Domínguez, Deng Qiang, Wang, Yu Xiang, Wang, Qi Wei, Wei, Lorenzo, Zane, and Shu Huan, Zhang
Subjects: 0106 biological sciences, 0303 health sciences, [SDV]Life Sciences [q-bio], Computational Biology, 010603 evolutionary biology, 01 natural sciences, 03 medical and health sciences, Databases, Genetic, micropsatellites, Genetics, Animals, Ecology, Evolution, Behavior and Systematics, Microsatellite Repeats, 030304 developmental biology, Biotechnology
Abstract: International audience; This article documents the addition of 234 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Acipenser sinensis, Aleochara bilineata, Aleochara bipustulata, Barbus meridionalis, Colossoma macropomum, Delia radicum, Drosophila nigrosparsa, Fontainea picrosperma, Helianthemum cinereum, Liomys pictus, Megabalanus azoricus, Pelteobagrus vachelli, Pleuragramma antarcticum, Podarcis hispanica type 1A, Sardinella brasiliensis and Sclerotinia homoeocarpa. These loci were cross-tested on the following species: Acipenser dabryanus, Barbus balcanicus, Barbus barbus, Barbus cyclolepis, Drosophila hydei, Drosophila melanogaster, Drosophila obscura, Drosophila subobscura, Fontainea australis, Fontainea fugax, Fontainea oraria, Fontainea rostrata, Fontainea venosa, Podarcis bocagei, Podarcis carbonelli, Podarcis liolepis, Podarcis muralis and Podarcis vaucheri.
Published: 2013
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28. Molecular analysis reveals high compartmentalization in aphid-primary parasitoid networks and low parasitoid sharing between crop and noncrop habitats

Author: Marion Maret, Alan Walton, Anne Le Ralec, Mathilde M. Besson, Darren M. Evans, Manuel Plantegenest, Stephane A. P. Derocles, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, School of Biological, Biomedical and Environmental Sciences, University of Hull, Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), AGROCAMPUS OUEST-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA)
Subjects: Crops, Agricultural, 0106 biological sciences, Competitive Behavior, Food Chain, agroecosystems, apparent competition, Molecular Sequence Data, Aphidiinae parasitoids, Biological pest control, Parasitism, Generalist and specialist species, 010603 evolutionary biology, 01 natural sciences, Intraspecific competition, Parasitoid, host–parasitoid communities, Genetics, Animals, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, 16S rRNA, Aphidiinae, Ecosystem, Ecology, Evolution, Behavior and Systematics, 2. Zero hunger, Aphid, biology, Ecology, Agriculture, 15. Life on land, biology.organism_classification, Hymenoptera, Ecological network, 010602 entomology, Aphids, food webs, France
Abstract: International audience; The ecosystem service of insect pest regulation by natural enemies, such as primary parasitoids, may be enhanced by the presence of uncultivated, semi-natural habitats within agro-ecosystems, although quantifying such host–parasitoid interactions is difficult. Here, we use rRNA 16S gene sequencing to assess both the level of parasitism by Aphidiinae primary parasitoids and parasitoid identity on a large sample of aphids collected in cultivated and uncultivated agricultural habitats in Western France. We used these data to construct ecological networks to assess the level of compartmentalization between aphid and parasitoid food webs of cultivated and uncultivated habitats. We evaluated the extent to which uncultivated margins provided a resource for parasitoids shared between pest and nonpest aphids. We compared the observed quantitative ecological network described by our molecular approach to an empirical qualitative network based on aphid–parasitoid interactions from traditional rearing data found in the literature. We found that the molecular network was highly compartmentalized and that parasitoid sharing is relatively rare between aphids, especially between crop and noncrop compartments. Moreover, the few cases of putative shared generalist parasitoids were questionable and could be due to the lack of discrimination of cryptic species or from intraspecific host specialization. Our results suggest that apparent competition mediated by Aphidiinae parasitoids is probably rare in agricultural areas and that the contribution of field margins as a source of these biocontrol agents is much more limited than expected. Further large-scale (spatial and temporal) studies on other crops and noncrop habitats are needed to confirm this.
Published: 2014
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29. Conception de systèmes de culture innovants pour la filière des légumes industrie de plein champ en Bretagne

Author: Puech, Camille, Bruaile, Arnaud, de Keyser, Eva, Le Ralec, Anne, Paraiso, Jérôme, Venard, Julie, Faloya, Vincent, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Issy les Moulineaux, PICARD Surgelés, ARDO, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: Ateliers de conception, Expérimentation, Pratiques agroécologiques, Sustainability, Design workshops, [SDV]Life Sciences [q-bio], DEXiPM-FV, Agro-ecological practices, Durabilité, Experimentation
Abstract: Dans le cadre d’un projet mené en partenariat avec différents acteurs de la filière des légumes industrie de Bretagne, une démarche de co-conception de systèmes de culture innovants est mise en place chez 4 agriculteurs. L’objectif est de réduire autant que possible l’impact environnemental et sanitaire de leurs pratiques et d’anticiper la disparition des produits phytosanitaires. Après une analyse des systèmes de culture initiaux, des ateliers collectifs ont permis de concevoir des systèmes innovants intégrant une diversité de pratiques agro-écologiques. Ces systèmes ont été expérimentés dès 2016 par les agriculteurs puis analysés à l’aide d’un modèle d’évaluation multicritères. Bien que les résultats mettent en évidence une diminution des performances économiques et sociales des systèmes, les 4 agriculteurs ont pu diminuer leurs IFT et se sont montrés très satisfaits des premiers changements réalisés. Une deuxième phase de conception-expérimentation a donc été programmée pour 2017, afin de pouvoir ajuster les systèmes conçus et réaliser les changements de pratiques qui n’ont pas pu être faits en 2016. Ces premiers résultats sont prometteurs compte tenu des importantes contraintes relatives à la filière des légumes industrie. A terme, les différents partenaires envisagent donc de diffuser les pratiques agro-écologiques vertueuses identifiées à plus large échelle., As part of a project carried out with various partners of the industrial vegetable sector in Brittany, the codesign of innovative cropping systems is implemented with 4 farmers. The target is to reduce as much as possible the environmental and health impact of their practices and to anticipate the phasing-out of agrochemical products. After an analysis of initial cropping systems, collective workshops led to the design of innovative systems integrating a diversity of agro-ecological practices. These systems were experimented by farmers in 2016, and analyzed using a multicriteria evaluation model. Although results show a decrease in economic and social performances of the systems, the 4 farmers were able to reduce their TFIs and were highly satisfied with the first modifications. A second design-experimentation step has therefore been scheduled for 2017 in order to adjust the systems and to realize the modifications that could not be made in 2016. These first results are promising given the important constraints associated to the industrial vegetable sector. Ultimately, the various partners are planning to disseminate on a larger scale the virtuous agro-ecological practices identified.
Published: 2017
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30. Two new species of aphid parasitoids (Hymenoptera, Braconidae, Aphidiinae) from the high arctic (Spitsbergen, Svalbard)

Author: Željko Tomanović, Anne Le Ralec, Jean-Christophe Simon, Yannick Outreman, Maurice Hullé, Bernard Chaubet, Stephane A. P. Derocles, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Fac Biol, University of Belgrade [Belgrade], French Polar Institute (Institut Paul Emile Victor) [426], Serbian Ministry of Education and Science [III43001], AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
Subjects: Spitsbergen, 0106 biological sciences, EUROPE, [SDV]Life Sciences [q-bio], ACYRTHOSIPHON-SVALBARDICUM, Hymenoptera, 010603 evolutionary biology, 01 natural sciences, INVERTEBRATES, Aphid parasitoids, Parasitoid, 03 medical and health sciences, Arctic environments, 14. Life underwater, Aphidiinae, SP-N, 030304 developmental biology, 0303 health sciences, Aphid, biology, Ecology, Insect biodiversity, biology.organism_classification, GENE, LIFE-CYCLE, New species, Arctic, Animal Science and Zoology, Species richness, Braconidae
Abstract: International audience; The high arctic Svalbard archipelago is characterized by a low insect species richness explained by both extreme living conditions and insularity. Here, we described two new species of Hymenopteran parasitoids found in Spitsbergen, the main island of Svalbard, using aphids as hosts. We named the first one Diaeretellus svalbardicum (Hymenoptera: Braconidae) because of morphological similarities with other European members of the Diaeretellus genus. D. svalbardicum parasitizes exclusively the aphid Acyrthosiphon svalbardicum, a species endemic to Svalbard. We also reported in D. svalbardicum a unique case of wing polymorphism with macropterous and micropterous forms in both genders. We named the second newly described parasitoid species Aphidius leclanti because of morphological similarities with other members of the Aphidius genus. Contrarily to D. svalbardicum, A. leclanti exploits the only two aphid species regularly found in Spitsbergen, A. svalbardicum and Sitobion calvulum. (C) 2012 Elsevier GmbH. All rights reserved.
Published: 2013
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31. Effects of spontaneous field margin vegetation and surrounding landscape on Brassica oleracea crop herbivory

Author: Anna Pollier, Bruno Jaloux, Yann Tricault, Anne Le Ralec, Armin Bischoff, Anne-Marie Cortesero, Elie Lamarre, Orlane Salvadori, Institut méditerranéen de biodiversité et d'écologie marine et continentale (IMBE), Centre National de la Recherche Scientifique (CNRS)-Institut de recherche pour le développement [IRD] : UMR237-Aix Marseille Université (AMU)-Avignon Université (AU), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, AGROCAMPUS OUEST, French Federal States ('régions') Bretagne, Pays de la Loire, Scientific Network GIS-PICleg, Avignon Université (AU)-Aix Marseille Université (AMU)-Institut de recherche pour le développement [IRD] : UMR237-Centre National de la Recherche Scientifique (CNRS), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
Subjects: 0106 biological sciences, cereal, Ecosystem service, parasitism, Context (language use), larvae, Biology, natural enemies, cabbage, 010603 evolutionary biology, 01 natural sciences, context, Crop, agricultural landscapes, Abundance (ecology), 2. Zero hunger, Herbivore, Ecology, biological-control, fungi, Species diversity, food and beverages, Plant community, sown wildflower strips, Vegetation, 15. Life on land, coccinella-septempunctata coleoptera, 010602 entomology, Agronomy, Biological control, Plant-insect interactions, Brassicaceae, Herbivore regulation, Plant cover, Animal Science and Zoology, Semi-natural habitats, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Agronomy and Crop Science
Abstract: International audience; Semi-natural structures of agricultural landscapes are known to provide important habitat functions for natural enemies of crop herbivores. Although several functions such as resource and shelter are related to plant species, the role of the floristic composition is not well understood. Using a correlative approach, we analysed interactions between plant functional groups of spontaneous field margin vegetation and the regulation of crop herbivores. We further compared the influence of the local plant community with that of landscape structure at different scales (50-500 m). We used Brassica oleracea crop plants as phytometers planted into field margins of 48 fields and observed correlations of explanatory variables (vegetation, landscape) and response variables (herbivore and natural enemy abundance, crop damage) for two consecutive years (24 fields x year(-1)). We observed significant positive and negative correlations between plant functional groups and variables related to crop herbivore regulation. In general, plant cover based-models provided a better fit than diversity-based models. Entomophilous flowering plants providing nectar showed a positive correlation to ladybird abundance and aphid parasitism and a negative relationship with major crop plant damage caused by leaf-chewing invertebrates. Cover and diversity of wild Brassicaceae species were positively correlated with flea beetle damage and abundance. Most correlations with plant functional groups remained significant after fitting variables of landscape structure. The density of semi natural habitats showed predominantly positive correlations to crop herbivore regulation, whereas the density of crops was negatively correlated. The number of significant relationships decreased from natural enemy to herbivore abundance and to plant damage. Our results demonstrate the relative importance of field margin vegetation for crop herbivore regulation. The differential responses to plant functional groups support the idea that designing specific plant mixtures may improve biological control. Additional effects of landscape variables suggest that a combination of local and landscape-scale management is the most promising strategy to optimise this ecosystem service. (C) 2016 Elsevier B.V. All rights reserved.
Published: 2016
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32. Are generalist Aphidiinae (Hym. Braconidae) mostly cryptic species complexes?

Author: Derocles, Stephane A. P., Plantegenest, Manuel, Rasplus, Jean Yves, Marie, Alexia, Evans, Darren M., Lunt, David H., Le Ralec, Anne, University of Hull, Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES), AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Centre de Biologie pour la Gestion des Populations (UMR CBGP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut de Recherche pour le Développement (IRD [France-Sud])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, We thank the ‘Conseil Regional de Bretagne’ for project funding. This study was also founded by the French NationalResearch Agency (Landscaphid project, ANR-09-STRA-05)., ANR-09-STRA-0005,LANDSCAPHPID,Influence du paysage sur les pucerons ravageurs des cultures et le potentiel de contrôle biologique - Application à l'ingénierie écologique pour la gestion des ravageurs(2009), Université de Rennes (UR), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: [SDV]Life Sciences [q-bio], [SDV.BV]Life Sciences [q-bio]/Vegetal Biology
Abstract: International audience; Aphidiinae are mostly composed of specialist parasitoids and the few species described as generalist are suspected to be composed of cryptic specialists, almost indistinguishable based on morphological characteristics. The use of molecular markers has proven to be a useful tool for revealing cryptic species complexes and here we use seven mitochondrial and nuclear gene fragments to study possible genetic differentiation among seven Aphidiinae generalists. Maximum likelihood (ML) trees and Bayesian Poisson tree processes (bPTP) models were conducted on each gene separately and on the seven genes together. The standard cytochrome c oxidase I barcode region appeared to be the most polymorphic and probably the best marker to reveal putative cryptic species. However, we showed with ML trees and bPTP models that a complementary use of mitochondrial and nuclear genes was the most relevant approach to reliably identify cryptic genetic clades in the Aphidiinae. Overall, most of the analysed generalist morphospecies were shown to be composed of subgroups related to the aphid host, some of them revealed as cryptic species by the species delimitation analysis. Further studies are needed to reveal the generality of this result in Aphidiinae.
Published: 2016
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33. Selecting volatiles to protect brassicaceous crops against the cabbage root fly, Delia radicum

Author: Alice Mortreuil, Sébastein Dugravot, Anne Le Ralec, Alan Kergunteuil, and Anne-Marie Cortesero
Subjects: 0106 biological sciences, Diamondback moth, biology, fungi, Green leaf volatiles, food and beverages, biology.organism_classification, 01 natural sciences, Predation, 010602 entomology, chemistry.chemical_compound, Horticulture, chemistry, Insect Science, Botany, Anthomyiidae, Beneficial insects, PEST analysis, Ecology, Evolution, Behavior and Systematics, Methyl salicylate, Delia radicum, 010606 plant biology & botany
Abstract: Volatiles resulting from plant–herbivore interactions play an important role in the behavioral decisions of phytophagous, predatory, and parasitoid insects and could be used for managing pest insects. However, to date and after about 40 years of research, documented studies on applications in the field remain extremely scarce. Delia radicum L. (Diptera: Anthomyiidae), the cabbage root fly, is a major pest of brassicaceous crops for which classical control strategies are currently lacking. Our previous studies showed that dimethyl disulfide (DMDS), a compound emitted by roots heavily infested by D. radicum larvae, was attractive for the fly’s main natural enemies and could lead to a reduction of 60% in number of eggs laid on treated plants in the field. As a follow-up of this work, we conducted another field study to select additional volatiles that could be used in a push–pull approach. Several synthetic herbivore-induced plant volatiles, selected on the basis of their potential action on the behavior of both the fly and its natural enemies, were placed in odor dispensers in experimental broccoli plots and their influence on oviposition by D. radicum and egg predation by ground-dwelling predators was assessed. Our results confirmed the role of DMDS in reducing D. radicum egg numbers on broccoli plants and revealed that (Z)-3-hexenyl acetate, a green leaf volatile released by recently damaged plants, strongly stimulated fly oviposition. Also, two of the compounds tested slightly modified predation activity of ground-dwelling predators: acetophenone decreased the proportion of predated patches, whereas methyl salicylate increased it. This study is a first step in designing a push–pull strategy to control the cabbage root fly.
Published: 2012
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34. Evolutionary ecology of the interactions between aphids and their parasitoids

Author: Anne Le Ralec, Jacques J. M. van Alphen, Joan van Baaren, Cécile Le Lann, Yannick Outreman, Marylène Poirié, Caroline Anselme, Biologie des organismes et des populations appliquées à la protection des plantes (BIO3P), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Biologie Fonctionnelle, Insectes et Interactions (BF2I), Institut National de la Recherche Agronomique (INRA)-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon, Interactions Biotiques et Santé Végétale, Institut National de la Recherche Agronomique (INRA), Interactions Biotiques et Santé Végétale (IBSV), Centre National de la Recherche Scientifique (CNRS)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut National de la Recherche Agronomique (INRA), Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA), Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Paysages, Changements Climatique, Biodiversité, Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Université de Lyon-Institut National des Sciences Appliquées (INSA), Institut National de la Recherche Agronomique (INRA)-Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, Institut National de la Recherche Agronomique (INRA)-Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), and Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes (UR)-Institut Ecologie et Environnement (INEE)
Subjects: 0106 biological sciences, media_common.quotation_subject, Biological pest control, Defence mechanisms, Insect, Hymenoptera, Biology, 010603 evolutionary biology, 01 natural sciences, General Biochemistry, Genetics and Molecular Biology, Host-Parasite Interactions, Animals, Adaptation, Aphidiinae, media_common, Aphid, Behavior, Animal, Ecology, General Immunology and Microbiology, Reproduction, Parasitoid communities, Aphididae, Biodiversity, General Medicine, biology.organism_classification, Biological Evolution, Diapause, Climatic change, 010602 entomology, Aphids, Evolutionary ecology, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, General Agricultural and Biological Sciences, Braconidae
Abstract: International audience; Many organisms, including entomopathogenous fungi, predators or parasites, use aphids as ressources. Parasites of aphids are mostly endoparasitoid insects, i.e. insects which lay eggs inside the body of an other insect which will die as a result of their development. In this article, we review the consequences of the numerous pecularities of aphid biology and ecology for their endoparasitoids, notably the Aphidiinae (Hymenoptera: Braconidae). We first examine the various mechanisms used by aphids for defence against these enemies. We then explore the strategies used by aphidiine parasitoids to exploit their aphid hosts. Finally, we consider the responses of both aphids and parasitoids to ecological constraints induced by seasonal cycles and to environmental variations linked to host plants and climate. The fundamental and applied interest of studying these organisms is discussed.
Published: 2010
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35. The delay in arrival of the parasitoid Diaeretiella rapae influences the efficiency of cabbage aphid biological control

Author: Sara Neuville, Anne Le Ralec, Bruno Jaloux, Yannick Outreman, AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, and Féderation Nationale des Agriculteurs Multiplicateurs de Semences
Subjects: 0106 biological sciences, Population, Biological pest control, 010603 evolutionary biology, 01 natural sciences, Parasitoid, Functional response, Braconidae, Release delay, education, 2. Zero hunger, education.field_of_study, Aphid, biology, Diaeretiella rapae, fungi, food and beverages, Aphididae, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, Hymenoptera, 010602 entomology, Horticulture, Agronomy, Brevicoryne brassicae, Insect Science, Biological control, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Agronomy and Crop Science
Abstract: International audience; The efficiency of the biological controlstrategies based on parasitoids, either as a release or a conservative measure, depends on the timely arrival or release of the parasitoids after colonization of the field by the pest. In this study, the effects of the delay between the cabbage aphid Brevicoryne brassicae (Hemiptera: Aphididae) infestation and the release of its parasitoid Diaeretiella rapae (Hymenoptera: Braconidae) and of the number of parasitoid releases on aphid population dynamics and host plant growth were investigated. When the parasitoids were released at the start of the infestation, 89.6 % of the aphids were parasitized one month later, and the damage to cabbage was low. The identical number of parasitoids released two weeks after the start of the infestation partially controlled the aphid population, but the growth of the cabbage was altered. The earliest introduction of the parasitoid to the crop led to an efficient host regulation, and the release in three times rather than in one time did not improve the control efficiency at this release delay. The implications for biological control strategies that use parasitoids of aphids are discussed.
Published: 2016
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36. Field and laboratory selection of brassicaceous plants that differentially affect infestation levels by Delia radicum

Author: Anne Marie Cortesero, Sébastien Dugravot, C. Paty, A. Le Ralec, V. Chaminade, S. Dourlot, Alan Kergunteuil, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Chercheur indépendant, GIS PIClÃ©g, AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Rennes 1 (UR1)
Subjects: Integrated pest management, trap plant, egg predators, brassicaceae, push–pull strategy, niveau d'infestation, Context (language use), Biology, medicine.disease_cause, delia radicum, Infestation, infestation level, Push–pull strategy, medicine, composé olfactif, cabbage root fly, piège attractif, plant attractiveness, 2. Zero hunger, Herbivore, stimulus olfactif, 'push-pull' strategy, attractive trap, fungi, olfactory stimuli, plante piège, food and beverages, 15. Life on land, biology.organism_classification, Crop protection, Agronomy, Insect Science, PEST analysis, cabbage root ﬂy, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, Agronomy and Crop Science, Delia radicum
Abstract: International audience; Several plant traits control plant-insect interactions and shape host range of herbivorous insects according to their degree of dietary specialization. Understanding how plant species diversity influences herbivore infestations is of interest for the development of alternative crop protection strategies. In a pest management context, an appropriate selection of plants can modify pest distribution at the field scale. To develop a push-pull' strategy against the cabbage root fly, Delia radicum, we conducted a field study to both determine which plants exhibit contrasted pest infestation levels and to evaluate their influence on egg predation activity. Our field experiment reveals that infestation levels of brassicaceous plants by the cabbage root fly in the field can vary considerably according to plant genotype and species, while the number of predated eggs is only slightly affected by plant species. Olfactometry studies carried out under laboratory conditions revealed that plants harbouring the highest number of eggs in the field were also highly attractive, suggesting that olfactory stimuli are responsible, at least partially, for the differential infestation levels observed in the field. In a push-pull' context, this study demonstrates that different brassicaceous plants could be used to redistribute cabbage root flies in broccoli crops without compromising herbivore control by natural enemies. In addition, the importance of plant volatiles for infestation levels suggests a potential for developing a semiochemically assisted push-pull' system in which trap plants would be enhanced by synthetic release of attractive compounds.
Published: 2015
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37. Oviposition Behavior of the Pollen Beetle (Meligethes aeneus): A Functional Study

Author: Régine Delourme, Maxime R. Hervé, Marie Trabalon, Anne Marie Cortesero, Anne Le Ralec, Nathan Garcia, Université européenne de Bretagne - European University of Brittany (UEB), Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Ethologie animale et humaine (EthoS), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Université de Caen Normandie (UNICAEN), Normandie Université (NU)-Normandie Université (NU)-Centre National de la Recherche Scientifique (CNRS), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), CJS grant from the French National Institute of Agronomical Research, Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, Université de Caen Normandie (UNICAEN), and Normandie Université (NU)-Normandie Université (NU)-Université de Rennes (UR)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Avian clutch size, Host (biology), [SDV]Life Sciences [q-bio], [SDV.BA]Life Sciences [q-bio]/Animal biology, education, fungi, Oilseed rape (Brassica napus), Seta, food and beverages, Biology, biology.organism_classification, behavioral sequence, Animal ecology, Insect Science, Botany, plant acceptability, Ovipositor, [SDV.NEU]Life Sciences [q-bio]/Neurons and Cognition [q-bio.NC], PEST analysis, Pollen beetle, insect pest, Ecology, Evolution, Behavior and Systematics, scanning electron microscopy, Meligethes aeneus
Abstract: International audience; The recognition by female phytophagous insects of a plant as a ‘good’ or ‘bad’ host for egg laying is based on a variety of cues (either visual, physical or chemical). Specific cues are often looked for during stereotypic oviposition behaviors, composed of several phases having their own function(s). In this study the oviposition behavior of the pollen beetle Meligethes aeneus, a pest which lays eggs in flower buds of only some brassicaceous plants, was described in detail on five oilseed rape (Brassica napus) genotypes. In parallel, setae borne by the ovipositor were characterized by scanning electron microscopy. Observations showed that the stereotypic oviposition sequence is functionally divided into three independent phases: external inspection, internal inspection and egg laying. The ovipositor plays a role in all phases by gaining information about external and internal bud parts. This role appears to be only physical since all the setae it bears are mechanoreceptors. Despite the fact that the pollen beetle is a specialist for oviposition, important variations in secondary metabolites that are typical of its host plant family (i.e., glucosinolates) on the bud did not influence clutch size. The crucial phase in the oviposition sequence seems to be the external inspection, during which poor and high-quality host plants are probably discriminated. Chemical information on bud surface is likely to be determinant in this process.
Published: 2015
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38. Perception-based foraging for competing resources: Assessing pest population dynamics at the landscape scale from heterogeneous resource distribution

Author: Sylvain Poggi, Nicolas Parisey, Yoann Bourhis, Anne Le Ralec, Youcef Mammeri, Anne-Marie Cortesero, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, UMR LAMFA, Université de Picardie Jules Verne (UPJV), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Laboratoire Amiénois de Mathématique Fondamentale et Appliquée - UMR CNRS 7352 (LAMFA), Université de Picardie Jules Verne (UPJV)-Centre National de la Recherche Scientifique (CNRS), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: 0106 biological sciences, Resource (biology), Foraging, Population, Resource distribution, Distribution (economics), Context (language use), 010603 evolutionary biology, 01 natural sciences, Delia radicum, 03 medical and health sciences, Energy supply, education, Multi-scale modelling, 030304 developmental biology, 2. Zero hunger, 0303 health sciences, education.field_of_study, business.industry, Ecology, Ecological Modeling, Environmental resource management, 15. Life on land, Geography, Crop protection, Population model, Resource perception, Metabolic currency, Reaction-diffusion equation, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, business
Abstract: International audience; Resource distribution, through its effects on individual foraging and survival, drives population dynamics across the landscape. In an agricultural context, resource distribution is therefore a key information in assessing whether or not a pest population may invade and persist in a given environment. Addressing this issue by means of numerical exploration requires a population model with a sound dependence on the landscape. In this paper, we demonstrate that this dependence is effectively secured by a multi-scale description of the population. We derived a reaction-diffusion population model accounting for two individual-scale processes determining resource utilisation: (1) resource perception as a determinant of mobility and (2) energy supply management as a determinant of survival. In this model, the distribution of two competing resources (feeding and laying sites) affects the spatial population dynamics of a dipteran pest through a heterogeneous dispersion of the individuals and a metabolic currency. We conducted a global sensitivity analysis to evaluate the impact of both individual-scale processes on the population dynamics. This exploration demonstrated the biological relevance of the model according to field observations and theoretical expectations. Our key finding is that resource perception and energy supply management appear as significant as the demographic component regarding the resulting dynamics of the pest. Building on its acute multi-scale landscape dependence, this model may be particularly useful for investigating the putative relationships between agricultural landscape features and pest outbreaks
Published: 2015
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39. Can imperfect host discrimination explain partial patch exploitation in parasitoids?

Author: A. Le Ralec, Jean-Sébastien Pierre, Yannick Outreman, and Eric Wajnberg
Subjects: 0106 biological sciences, Ecology, biology, Host (biology), Homoptera, Aphididae, Hymenoptera, biology.organism_classification, 010603 evolutionary biology, 01 natural sciences, Parasitoid, 010602 entomology, Sitobion avenae, Insect Science, PEST analysis, Braconidae
Abstract: 1. Host discrimination by Aphidius rhopalosiphi (De Stefani Perez) (Hymenoptera: Braconidae) was first studied on the grain aphid Sitobion avenae (Fabricius) (Homoptera: Aphididae). Females tended to avoid oviposition in hosts parasitised 3h earlier. No evidence of host discrimination ability on freshly parasitised hosts was suggested, however, and ovipositional experience had no effect on host discrimination. 2. The effects of host discrimination ability on the exploitation strategy of patches containing different proportions of unparasitised hosts and hosts parasitised for 3 h were studied. Females spent less time on patches with a higher proportion of parasitised hosts, reflecting the females' ability to perceive the potential profitability of the patch. This ability may be based on the nature of the hosts encountered (unparasitised or parasitised). 3. Incomplete exploitation of unparasitised hosts was also observed. It seems that this partial exploitation is related to the inability of A. rhopalosiphi to recognise freshly parasitised hosts. As a female may experience a risk of self-superparasitism during patch depletion, this could promote early departure from incompletely exploited patches. 4. The effect of previous experience on the patch exploitation strategy was also assessed. Females were tested twice on two patches of the same quality. Results suggested that the experience acquired during a previous visit led the females to leave the patch sooner and to lay fewer eggs in parasitised hosts. 5. Patch exploitation strategy may therefore be the result of different factors such as host discrimination and experience. The evolutionary consequences of the results are discussed.
Published: 2001
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40. Larval hitch-hiking and adult flight are two ways of aphidiinae parasitoids long-range dspersal

Author: Manuel Plantegenest, Evelyne Turpeau Ait-Ighil E, Charles-Antoine Dedryver, Bernard Chaubet, Anne Le Ralec, Stephane A. P. Derocles, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, AGROCAMPUS OUEST, Conseil Regional de Bretagne, Agence Nationale de la Recherche-Landscaphid 16 project (ANR-09-STRA-05), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), ANR-19-JPW2-0005,STRATALS,Stratification of presymptomatic amyotrophic lateral sclerosis: the development of novel imaging biomarkers(2019), AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: Male, Nymph, Food Chain, animal structures, Population, Population Dynamics, Wasps, Biological pest control, Parasitism, Parasitoid, Host-Parasite Interactions, Species Specificity, Animals, DNA barcoding, parasitoid dispersion, education, Aphidiinae, Ecology, Evolution, Behavior and Systematics, education.field_of_study, Aphid, Suction trap, Ecology, biology, fungi, migratory aphid, food and beverages, biochemical phenomena, metabolism, and nutrition, biology.organism_classification, molecular detection, [SDV.MP]Life Sciences [q-bio]/Microbiology and Parasitology, Insect Science, Aphids, Flight, Animal, Larva, Biological dispersal, Female, France, Animal Distribution
Abstract: International audience; Dispersal strategies and success of pests' natural enemies widely influence the efficiency of biological control. In this study, we compare two dispersal strategies among Aphidiinae parasitoids: eggs and larvae dispersal through winged aphid flight and active dispersal by adult parasitoids. Using a molecular method applied to a sample of >2,000 winged migratory aphids captured in a suction trap situated in Western France, we assessed the proportion of winged aphids carrying an aphidiine larva. In the six most abundant aphid species, we found an average parasitism rate of migrating aphids close to 1% and identified seven different, mainly generalist, parasitoid species. We also identified the species and the sex of adult Aphidiinae captured by the suction trap based on morphological criteria. We found that dispersing adult parasitoids were almost exclusively female. Parasitoid dispersal strategy seems to be species-dependant but this result needs to be confirmed by an exhaustive analysis of winged aphids captured. We discuss the possible impact of the low parasitism rate of winged aphids on parasitoid population dynamics and the importance of these results in the context of biological control and of the study of food webs between aphids and their natural enemies.
Published: 2014
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41. Effects of field and landscape variables on crop colonization and biological control of the cabbage root fly Delia radicum

Author: Lucie Raymond, Anne Marie Cortesero, Denis Poinsot, Jacques Baudry, Céline Josso, Anne Le Ralec, Julia Saulais, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Université européenne de Bretagne - European University of Brittany (UEB), Dynamiques Forestières dans l'Espace Rural (DYNAFOR), Institut National de la Recherche Agronomique (INRA)-École nationale supérieure agronomique de Toulouse [ENSAT]-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées, SAD Paysage (SAD Paysage), Institut National de la Recherche Agronomique (INRA)-AGROCAMPUS OUEST, French Ministry for Research, Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure Agronomique de Toulouse-Institut National Polytechnique (Toulouse) (Toulouse INP), AGROCAMPUS OUEST-Institut National de la Recherche Agronomique (INRA), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, Institut National de la Recherche Agronomique (INRA)-École nationale supérieure agronomique de Toulouse (ENSAT), Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National Polytechnique (Toulouse) (Toulouse INP), and Université de Toulouse (UT)-Université de Toulouse (UT)
Subjects: 0106 biological sciences, Integrated pest management, Colonization, Crop damages, Infestation, [SDV]Life Sciences [q-bio], Geography, Planning and Development, Biological pest control, Predation, Generalist and specialist species, 010603 evolutionary biology, 01 natural sciences, Delia radicum, Spatial extent, Nature and Landscape Conservation, 2. Zero hunger, Ecology, biology, business.industry, Agroforestry, Pest control, 15. Life on land, biology.organism_classification, Pest management, 010602 entomology, 13. Climate action, Agriculture, Parasitism, Biological control, PEST analysis, Landscape ecology, business
Abstract: International audience; Agriculture intensification has deeply modified agroecosystems from field to landscape scales. To achieve successful pest control using natural enemies, understanding species interactions over all scales remains a challenge. Using the cabbage root fly as a model, we studied whether field and landscape characteristics influenced colonization and infestation of broccoli fields by the pest and its control by natural enemies. We also determined whether species of different trophic level or host specialization would respond to environmental characteristics at the same spatial extent. During a multiple-species and multiple-spatial extent study in northwestern France, we recorded pest colonization and infestation in 68 fields, collected associated natural enemies and assessed crop damages. In each field, we considered management practices and characterized the surrounding landscape in 50-500 m-wide buffers. Our main findings are that Delia radicum and its main natural enemies respond to both field and landscape characteristics. Semi-natural areas supported both crop colonization by pests and natural enemy action. The pest and its enemies differed in their responses to field or landscape variables. Landscape elements such as field banks favored the movement of the pest while impeding the movement of some natural enemies. Pest pressure did not increase with the neighboring density of Brassica crops. The presence of natural enemies did not reduce crop damage but reduced pest emerging rates. Finally, specialist parasitoids responded to the landscape at larger spatial extents than generalists. These results outline the complexity of improving pest control through landscape management.
Published: 2013
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42. Egg contents in relation to host-feeding in some parasitic hymenoptera

Author: A. Le Ralec
Subjects: 0106 biological sciences, food.ingredient, biology, Ecology, Host (biology), Zoology, Plant Science, Hymenoptera, biology.organism_classification, 010603 evolutionary biology, 01 natural sciences, Parasitoid, 010602 entomology, Feeding behavior, food, Animal ecology, Insect Science, Yolk, embryonic structures, Hemolymph, General Agricultural and Biological Sciences, Agronomy and Crop Science, Ecology, Evolution, Behavior and Systematics
Abstract: Using transmission electron microscopy, egg content is studied in 10 parasitoid species, which either feed on host hemolymph or do not. As expected, hydropic eggs were found to contain little yolk which is only lipoid. In host-feeding species, the yolk contains a great number of typical protein bodies whereas in species that do not host-feed and which produce large eggs, the yolk contain very different bodies.
Published: 1995
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43. Prédation des pucerons par un cortège d’ennemis naturels sur Brassicacées légumières : quantification et facteurs de variation à l’échelle du paysage agricole

Author: Yann Tricault, Armin Bischoff, Cortesero, A. M., Bruno Jaloux, Parisey, N., Anne Le Ralec, Salvadori, O., Saulais, J., Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Biologie des organismes et des populations appliquées à la protection des plantes (BIO3P), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, AGROCAMPUS OUEST-Université de Rennes 1 (UR1), and Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA)
Subjects: [SDV.BV.AP]Life Sciences [q-bio]/Vegetal Biology/Plant breeding, ECOLOGY
Abstract: Prédation des pucerons par un cortège d’ennemis naturels sur Brassicacées légumières : quantification et facteurs de variation à l’échelle du paysage agricole
Published: 2012

44. Selecting volatiles to protect brassicaceous crops against the cabbage root fly, Delia radicum

Author: Kergunteuil, Alan, Dugravot, Sébastein, Mortreuil, Alice, Le Ralec, Anne, Cortesero, Anne Marie, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
Subjects: dimethyl disulfide, predators, conservation biological control, field-evaluation, biological control, natural enemies, (Z)-3-hexenyl acetate, push-pull, induced plant volatiles, staphylinid, Anthomyiidae, green leaf volatiles, diamondback moth, flowering plants, Diptera, fungi, herbivore‐induced plant volatiles, food and beverages, plutella-xylostella, herbivore-induced plant volatiles, beneficial insects, [SDV.BV.AP]Life Sciences [q-bio]/Vegetal Biology/Plant breeding, field study, parasitic hymenoptera, ENTOMOLOGY, push–pull, [SDE.BE]Environmental Sciences/Biodiversity and Ecology, conspecific females, oviposition, Predator
Abstract: Publication Inra prise en compte dans l'analyse bibliométrique des publications scientifiques mondiales sur les Fruits, les Légumes et la Pomme de terre. Période 2000-2012. http://prodinra.inra.fr/record/256699; International audience; Volatiles resulting from plantherbivore interactions play an important role in the behavioral decisions of phytophagous, predatory, and parasitoid insects and could be used for managing pest insects. However, to date and after about 40 years of research, documented studies on applications in the field remain extremely scarce. Delia radicum L. (Diptera: Anthomyiidae), the cabbage root fly, is a major pest of brassicaceous crops for which classical control strategies are currently lacking. Our previous studies showed that dimethyl disulfide (DMDS), a compound emitted by roots heavily infested by D. radicum larvae, was attractive for the flys main natural enemies and could lead to a reduction of 60% in number of eggs laid on treated plants in the field. As a follow-up of this work, we conducted another field study to select additional volatiles that could be used in a pushpull approach. Several synthetic herbivore-induced plant volatiles, selected on the basis of their potential action on the behavior of both the fly and its natural enemies, were placed in odor dispensers in experimental broccoli plots and their influence on oviposition by D. radicum and egg predation by ground-dwelling predators was assessed. Our results confirmed the role of DMDS in reducing D. radicum egg numbers on broccoli plants and revealed that (Z)-3-hexenyl acetate, a green leaf volatile released by recently damaged plants, strongly stimulated fly oviposition. Also, two of the compounds tested slightly modified predation activity of ground-dwelling predators: acetophenone decreased the proportion of predated patches, whereas methyl salicylate increased it. This study is a first step in designing a pushpull strategy to control the cabbage root fly.
Published: 2012
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45. A universal method for the detection and identification of Aphidiinae parasitoids within their aphid hosts

Author: Pierre Taberlet, Manuel Plantegenest, Jean-Christophe Simon, Anne Le Ralec, Stephane A. P. Derocles, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), 'Conseil Regional de Bretagne', French National Research Agency [ANR-09-STRA-05], French GIS Picleg (Brassinse Project), ANR-19-JPW2-0005,STRATALS,Stratification of presymptomatic amyotrophic lateral sclerosis: the development of novel imaging biomarkers(2019), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), and Université de Rennes (UR)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-INSTITUT AGRO Agrocampus Ouest
Subjects: 0106 biological sciences, hymenoptera-braconidae, MESH: Sequence Analysis, DNA, [SDV]Life Sciences [q-bio], Wasps, dna, MESH: Base Sequence, 01 natural sciences, DNA barcoding, Parasitoid, RNA, Ribosomal, 16S, MESH: Animals, Aphidiinae, phylogenetic-relationships, LWRh, Aphid, biology, food web, communities, MESH: RNA, Ribosomal, 16S, molecular detection, DNA, Intergenic, southeastern europe, MESH: Wasps, BIOCHEMISTRY & MOLECULAR BIOLOGY, MESH: Aphids, Biotechnology, MESH: DNA Primers, Mitochondrial DNA, 16S, molecular markers, MESH: Host Specificity, Molecular Sequence Data, Parasitism, 010603 evolutionary biology, DNA sequencing, Host Specificity, cereal aphids, pcr, Botany, Genetics, Animals, DNA Barcoding, Taxonomic, gene, MESH: DNA Barcoding, Taxonomic, parasitoid, Ecology, Evolution, Behavior and Systematics, DNA Primers, MESH: DNA, Intergenic, MESH: Molecular Sequence Data, Base Sequence, Host (biology), biological-control, fungi, Sequence Analysis, DNA, sequence, biology.organism_classification, 010602 entomology, [SDV.BV.AP]Life Sciences [q-bio]/Vegetal Biology/Plant breeding, Evolutionary biology, Aphids
Abstract: International audience; Molecular methods are increasingly used to detect and identify parasites in their hosts. However, existing methods are generally not appropriate for studying complex host-parasite interactions because they require prior knowledge of species composition. DNA barcoding is a molecular method that allows identifying species using DNA sequences as an identification key. We used DNA amplification with primers common to aphid parasitoids and sequencing of the amplified fragment to detect and identify parasitoids in their hosts, without prior knowledge on the species potentially present. To implement this approach, we developed a method based on 16S rRNA mitochondrial gene and LWRh nuclear gene. First, we designed two primer pairs specific to Aphidiinae (Hymenoptera), the main group of aphid parasitoids. Second, we tested whether the amplified regions could correctly identify Aphidiinae species and found that 61 species were accurately identified of 75 tested. We then determined the ability of each primer pair to detect immature parasitoids inside their aphid host. Detection was earlier for 16S than for LWRh, with parasitoids detected, respectively, 24 and 48 h after egg injection. Finally, we applied this method to assess parasitism rate in field populations of several aphid species. The interest of this tool for analysing aphid-parasitoid food webs is discussed.
Published: 2012
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46. Identification of molecular markers for DNA barcoding in the Aphidiinae (Hym. Braconidae)

Author: Corinne Cruaud, Stephane A. P. Derocles, Anne Le Ralec, Jean-Yves Rasplus, Astrid Cruaud, Bernard Chaubet, Manuel Plantegenest, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: 0106 biological sciences, Genetic Markers, Mitochondrial DNA, hymenoptera-braconidae, long, Molecular Sequence Data, introgression, Introgression, Locus (genetics), genus, 010603 evolutionary biology, 01 natural sciences, DNA barcoding, Electron Transport Complex IV, 03 medical and health sciences, Phylogenetics, mitochondrial-dna, Botany, Genetics, Animals, DNA Barcoding, Taxonomic, biological-control agent, Aphidiinae, phylogenetic-relationships, parasitoid, Ecology, Evolution, Behavior and Systematics, Phylogeny, 030304 developmental biology, 0303 health sciences, biology, oxidase subunit-i, biology.organism_classification, wavelength rhodopsin, [SDV.BV.AP]Life Sciences [q-bio]/Vegetal Biology/Plant breeding, aphid, Genetic marker, Evolutionary biology, Aphids, specimens, parasitoid flies diptera, extraction, Insect Proteins, southeastern europe, cytochrome c oxydase I, Braconidae, BIOCHEMISTRY & MOLECULAR BIOLOGY, Biotechnology
Abstract: Correspondence: Stephane Derocles, Fax: +33 2 23 48 51 70; E-mail: stephane.derocles@agrocampus-ouest.fr; International audience; Reliable identification of Aphidiinae species (Braconidae) is a prerequisite for conducting studies on aphidparasitoid interactions at the community level. However, morphological identification of Aphidiinae species remains problematic even for specialists and is almost impossible with larval stages. Here, we compared the efficiency of two molecular markers [mitochondrial cytochrome c oxydase I (COI) and nuclear long wavelength rhodopsin (LWRh)] that could be used to accurately identify about 50 species of Aphidiinae that commonly occur in aphidparasitoid networks in northwestern Europe. We first identified species on a morphological basis and then assessed the consistency of genetic and morphological data. Probably because of mitochondrial introgression, Aphidius ervi and A.microlophii were indistinguishable on the basis of their COI sequences, whereas LWRh sequences discriminated these species. Conversely, because of its lower variability, LWRh failed to discriminate two pairs of species (Aphidius aquilus, Aphidius salicis, Lysiphlebus confusus and Lysiphlebus fabarum). Our study showed that no unique locus but a combination of two genes should be used to accurately identify members of Aphidiinae.
Published: 2012
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47. Structure du paysage en parcelles de Brassicacées : impact sur les insectes phytophages et leurs ennemis naturels

Author: Cortesero, A. M., Anne Le Ralec, Saulais, J., Ezanic, A., Baudry, J., Armin Bischoff, Bruno Jaloux, Parisey, N., Salvadori, O., Yann Tricault, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Biologie des organismes et des populations appliquées à la protection des plantes (BIO3P), AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: Biological Control, [SDV.BV.PEP]Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy
Abstract: Structure du paysage en parcelles de Brassicacées : impact sur les insectes phytophages et leurs ennemis naturels.
Published: 2011

48. Aphid – parasitoid food web in crops and field margins

Author: Derocles, S., Le Ralec, Anne, Fedde, R., Gerardin, C., Hidalgo, K., Kamenova, S., Marrec, R., Martin, L., Walton, A., Plantegenest, Manuel, Institut de Génétique, Environnement et Protection des Plantes (IGEPP), AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: Ecology, [SDV.BV.PEP]Life Sciences [q-bio]/Vegetal Biology/Phytopathology and phytopharmacy
Abstract: Les plantes sont sessiles et les flux génétiques entre populations sont donc limités. Cette faible mobilité renforce une sélection divergente dans des environnements contrastés. Par conséquent, on peut partir du principe que dans un milieu donné, les populations locales présentent une "fitness" supérieure à celle des populations non locales. Cependant, les mécanismes, les facteurs clés et les échelles de l'adaptation locale sont peu connus. Dans le cadre de deux projets, nous avons analysé les facteurs conduisant à l'adaptation locale et en particulier, le rôle des interactions biotiques. Le premier programme une transplantation réciproque entre 3 pays européens qui vise à comparer l'importance du sol et du climat, et à étudier l'influence de la communauté végétale du voisinage. Le deuxième projet est centré sur les interactions trophiques. Une manipulation des phytophages principaux dans des transplantations réciproques permet d'évaluer leur rôle dans l'adaptation locale. Ces transplantations sont accompagnées par des " common garden experiments " afin d'évaluer l'importance de l'origine des végétaux pour la restauration écologique. Dans les deux programmes de recherche, la théorie d'adaptation locale a été confirmée pour 3 espèces végétales sur 4. Nous avons trouvé une adaptation au site (climat) mais pas au sol d'origine. Une influence des facteurs biotiques a été mise en évidence mais dans des sens opposés, soit renforçant, soit affaiblissant l'adaptation. La co-évolution entre adaptation des plantes et des phytophages ne permet donc pas des conclusions générales. Néanmoins, nos études ont montré que chaque implantation de végétaux non-locaux change les interactions biotiques.
Published: 2011

49. Abdominal sensory equipment involved in external host discrimination in a solitary parasitoid wasp

Author: Marlène Goubault, Anne-Marie Cortesero, Julie Fourrier, Anne Le Ralec, Chrystelle Paty, Sonia Dourlot, Biologie des organismes et des populations appliquées à la protection des plantes (BIO3P), AGROCAMPUS OUEST, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, and Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST
Subjects: 0106 biological sciences, Histology, Population, Wasps, HYMENOPTERA, Parasitism, Zoology, EPIDINOCARSIS-LOPEZI, TRICHOGRAMMATIDAE, Hymenoptera, OVIPOSITION BEHAVIOR, MESH: Abdomen, 010603 evolutionary biology, 01 natural sciences, MESH: Host-Parasite Interactions, Parasitoid, Parasitoid wasp, Host-Parasite Interactions, Lepidoptera genitalia, ULTRASTRUCTURE, MESH: Behavior, Animal, Abdomen, HYM, [SDV.BV]Life Sciences [q-bio]/Vegetal Biology, Animals, MESH: Animals, Sensilla, education, Instrumentation, education.field_of_study, biology, Behavior, Animal, Host (biology), fungi, ACCEPTANCE BEHAVIOR, HETEROPTERA, Anatomy, biology.organism_classification, MESH: Sensilla, LEPIDOPTERA, 010602 entomology, Medical Laboratory Technology, Ovipositor, MORPHOLOGY, Female, MESH: Wasps, MESH: Female
Abstract: Already parasitized hosts are often of poorer quality than healthy hosts. It is therefore usually advantageous for parasitoid females to recognize and reject them. Parasitized hosts can be identified on the basis of various physical or chemical marks present on the surface or inside the hosts or their surroundings in the case of concealed host. Here we studied host discrimination behaviors of females of a certain population of Pachycrepoideus vindemmiae, a solitary ectoparasitoid, which are known to reject large-sized parasitized hosts after an abdominal examination of their surface. We first investigated females' recognition behaviors of host parasitism status when confronted to small-sized hosts (Drosophila melanogaster pupae) as host size may influence the use of different cues for host selection. We showed that, in such a situation, females also discriminate parasitized hosts after an external host exploration with the tip of their ovipositor sheath (third valvulae). We then described the sense organs present on the different parts of the ovipositor by means of scanning and transmission electron microscopy analysis. As the extremity of the third valvulae bears only one type of sensilla that appears to be chemoreceptors, we considered these sensilla as highly likely to be involved in host discrimination in P. vindemmiae. To our knowledge, this is the first time that receptors located on the ovipositor sheath are described as implicated in host discrimination in parasitoid wasps. We discuss potential chemical markers that might be detected by these receptors.
Published: 2011
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50. Confronting a spatialy explicit population model with biased random walk to agroecosystems complexity

Author: Parisey, N., Yann Tricault, Anne Le Ralec, Cortesero, A. M., Institut de Génétique, Environnement et Protection des Plantes (IGEPP), Institut National de la Recherche Agronomique (INRA)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-AGROCAMPUS OUEST, AGROCAMPUS OUEST-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut National de la Recherche Agronomique (INRA), Institut National de la Recherche Agronomique (INRA)-Université de Rennes (UR)-AGROCAMPUS OUEST, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)
Subjects: [SDV.IDA.SMA]Life Sciences [q-bio]/Food engineering/domain_sdv.ida.sma, AGRONOMY
Abstract: Although a national strategy for the coexistence of GM and conventional/organic crops in Ireland has been published (McGill et al 2005) measures pertaining to the coexistence of GM and non-GM oilseed rape (OSR) crops was omitted pending the completion of
Published: 2011

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