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Little is known about the seed ecology of native plants from subalpine and alpine vegetation zones on oceanic islands, although their biodiversity is unique and vulnerable (e.g. facing fires and biological invasions). This study of seed germination focuses on five species, which are representative of the subalpine shrubland of Reunion Island. The main objectives are to identify the presence of dormancy and light requirements, and to evaluate whether GA3 or a smoke-infused water could substitute for the light requirement for seed germination. Over one month, germination tests were performed under different conditions at three temperatures (15, 20 and 25 °C), in light (12-hours light/12-hours dark) and in dark. Seeds were also treated using a single spraying of gibberellic acid (GA3 at 1000 ppm) and a smoke-infused water (named Smoke Water in the study). No dormancy was detected for Stoebe passerinoides. For Erica reunionensis, Agarista buxifolia, Hubertia tomentosa and Hypericum lanceolatum subsp. angustifolium, a potential non-deep physiological dormancy (with a conditional dormancy state) was detected. Moreover, for Agarista buxifolia and Erica reunionensis (Ericaceae), light is required for seed germination. Gibberellic acid (GA3 at 1000 ppm) substitutes for light, except at 25 °C for E. reunionensis. Smoke Water does not improve seed germination, except at 15 °C in dark for E. reunionensis. A better understanding of seed germination for species from subalpine and alpine vegetation zones will mean better threat management and restoration actions.

Les attaques de mouches des fruits sont la cause, chaque année, de nombreux dégâts sur les cultures fruitières et légumières dans les îles de l'océan Indien, et l'introduction non intentionnelle de nouvelles espèces représente toujours une menace supplémentaire de pertes importantes de récoltes. L'amélioration des méthodes de lutte contre les ravageurs passe notamment par une meilleure connaissance de ceux-ci et de leurs foyers potentiels de multiplication. Ce guide présente l'ensemble des plantes-hôtes des différentes espèces de mouches des fruits (Tephritidae), qui ont été recensées aux Comores, à Madagascar, à Maurice, à Mayotte, à La Réunion et aux Seychelles. Chaque plante-hôte est illustrée par des photos (fleurs, fruits, feuillage) et fait l'objet d'une brève description botanique ; les noms vernaculaires de ces plantes sont signalés dans les différentes langues et créoles de la zone. Les différentes espèces de mouches sont mentionnées pour chacune des plantes-hôtes et pour chacune des différentes îles. Sont présentées également des indications sur la qualité et l'importance du fruit vis-à-vis des mouches. De plus, des données sont proposées sur la répartition géographique, l'abondance et les périodes de fructification des plantes-hôtes. Enfin, sont présentés quelques éléments de taxonomie des espèces de mouches les plus communes dans les îles du Sud-Ouest de l'océan Indien.

Recent theory suggests that the geographic location of island radiations (local accumulation of species diversity due to cladogenesis) can be predicted based on island area and isolation. Crickets are a suitable group for testing these predictions, as they show both the ability to reach some of the most isolated islands in the world, and to speciate at small spatial scales. Despite substantial song variation between closely related species in many island cricket lineages worldwide, to date this characteristic has not received attention in the western Indian Ocean islands; existing species descriptions are based on morphology alone. Here we use a combination of acoustics and DNA sequencing to survey these islands for Ornebius crickets. We uncover a small but previously unknown radiation in the Mascarenes, constituting a three-fold increase in the Ornebius species diversity of this archipelago (from two to six species). A further new species is detected in the Comoros. Although double archipelago colonisation is the best explanation for species diversity in the Seychelles, in situ cladogenesis is the best explanation for the six species in the Mascarenes and two species of the Comoros. Whether the radiation of Mascarene Ornebius results from intra- or purely inter- island speciation cannot be determined on the basis of the phylogenetic data alone. However, the existence of genetic, song and ecological divergence at the intra-island scale is suggestive of an intra-island speciation scenario in which ecological and mating traits diverge hand-in-hand. Our results suggest that the geographic location of Ornebius radiations is partially but not fully explained by island area and isolation. A notable anomaly is Madagascar, where our surveys are consistent with existing accounts in finding no Ornebius species present. Possible explanations are discussed, invoking ecological differences between species and differences in environmental history between islands.

Recent theory suggests that the geographic location of island radiations (local accumulation of species diversity due to cladogenesis) can be predicted based on island area and isolation. Crickets are a suitable group for testing these predictions, as they show both the ability to reach some of the most isolated islands in the world, and to speciate at small spatial scales. Despite substantial song variation between closely related species in many island cricket lineages worldwide, to date this characteristic has not received attention in the western Indian Ocean islands; existing species descriptions are based on morphology alone. Here we use a combination of acoustics and DNA sequencing to survey these islands for Ornebius crickets. We uncover a small but previously unknown radiation in the Mascarenes, constituting a three-fold increase in the Ornebius species diversity of this archipelago (from two to six species). A further new species is detected in the Comoros. Although double archipelago colonisation is the best explanation for species diversity in the Seychelles, in situ cladogenesis is the best explanation for the six species in the Mascarenes and two species of the Comoros. Whether the radiation of Mascarene Ornebius results from intra- or purely inter- island speciation cannot be determined on the basis of the phylogenetic data alone. However, the existence of genetic, song and ecological divergence at the intra-island scale is suggestive of an intra-island speciation scenario in which ecological and mating traits diverge hand-in-hand. Our results suggest that the geographic location of Ornebius radiations is partially but not fully explained by island area and isolation. A notable anomaly is Madagascar, where our surveys are consistent with existing accounts in finding no Ornebius species present. Possible explanations are discussed, invoking ecological differences between species and differences in environmental history between islands.

This paper summarizes current knowledge of the occurrence of Dacini fruit flies in the Comoro archipelago of the Indian Ocean. Ten species are confirmed as occurring in the archipelago: Bactrocera invadens Drew, Tsuruta & White, 2005, Dacus bivittatus (Bigot, 1858), D. ciliatus Loew, 1862, D. etiennellus Munro, 1984, D. punctatifrons Karsch, 1887, D. vertebratus Bezzi, 1908 (all Dacina), Ceratitis capitata (Wiedemann, 1824), C. malgassa Munro, 1939, Neoceratitis cyanescens (Bezzi, 1923), and Trirhithrum nigerrimum (Bezzi, 1913) (all Ceratitidina). Records of Bactrocera cucurbitae (Coquillett, 1899) remain unconfirmed. The fauna of the Comoros is briefly compared to that of other islands in the western Indian Ocean.

This paper summarizes current knowledge of the occurrence of Dacini fruit flies in the Comoro archipelago of the Indian Ocean. Ten species are confirmed as occurring there: Bactrocera invadens Drew, Tsuruta & White, 2005, Dacus bivittatus (Bigot, 1858), D. ciliatus Loew, 1862, D. etiennellus Munro, 1984, D. punctatifrons Karsch, 1887, D. vertebratus Bezzi, 1908 (all Dacina), Ceratitis capitata (Wiedemann, 1824), C. malgassa Munro, 1939, Neoceratitis cyanescens (Bezzi, 1923), and Trirhithrum nigerrimum (Bezzi, 1913) (all Ceratitidina). Records of Bactrocera Cucurbitae (Coquillett, 1899) remain unconfirmed. The fauna of the Comoros is briefly compared to that of other islands in the western Indian Ocean.

Background. Since the 60's, trimedlure has been the main para-pheromone used to attract the males of a series of Ceratitis spp. of economic importance, such as the Mediterranean Fruit Fly C. capitata or the Natal fruit fly, C. rosa, for monitoring or detection purposes. In recent years, within a FAO-IAEA coordinated programme, research has been conducted on the possible use of some natural essential oils to improve the sexual competitiveness of the males of such species, in the framework of SIT (Sterile Insect Technique) programmes. Within these programmes the strong attractiveness of Ginger Root Oil (GRO) for the males of some Ceratitis spp. has been confirmed. Based on these results, it appeared useful to compare the attractiveness of a recently available commercial dispenser of Enriched Ginger Oil (Insect Science SA, Tzaneen, South Africa) with that of a standard trimedlure dispenser, in field trapping experiments. More recently, field-cage tests were carried out to determine the factors (age, food status, mating...) influencing the male response in both species. Methods. Four field experiments were conducted in 2009-2010 on different crops. The first one was carried out in a Citrus orchard situated in Bassin Martin, in the south of the island, at an altitude of 290 m a.s.l.. The second trial was carried out in another Citrus orchard, in Petite Ile in the south (alt.: 300m) and the third one in Etang-Salé, in the south-west, in a chilli plot (alt.: 10m). Finally a fourth trial, set up in Piton Armand on the East in a Chinese guava plot (alt.: 450m), is still in progress. For each trial, two types of attractants were compared in Tephri-traps (Sorygar, Spain): Enriched Ginger Oil (EGO) ("Pherolure", Insect Science SA, Tzaneen, South Africa) and trimedlure (Agrisense BCS Ltd, Pontypridd, UK). The attractant dispensers were placed in a small plastic basket at the top of the trap, while a strip of DDVP was placed at the bottom of the Tephri-trap to kill the adult flie

La diversité et le mode de vie de ces organismes utiles, indispensables à la bonne santé d'une agriculture durable, commencent à être mieux connus. Ce petit ouvrage fournit des clés pour une première reconnaissance de ces auxiliaires, notamment les insectes et acariens, et présente leur distribution, leur biologie, leur régime alimentaire et leur comportement. Abondamment illustré, il deviendra un outil de travail pour les chercheurs, les agriculteurs et techniciens agricoles, un sujet de surprise et d'émerveillement pour les amateurs curieux.

Le psylle asiatique des agrumes #Diaphorina citri# Kuwayama est particulièrement dangereux pour les plantations d'agrumes car c'est l'un des deux psylles vecteurs de la maladie du greening des agrumes ou Huanglongbing. Cette maladie, qui limite la longévité des arbres, est due à une bactérie intracellulaire qui affecte principalement le phloème. À l'île de la Réunion, le greening détecté en 1967 était l'obstacle principal du développement de la culture des agrumes. Le contrôle de son vecteur #D. citri#, par introduction à partir d'Inde et multiplication sur place de son parasitoïde spécifique #Tamarixia radiata# (Waterston), a été effectué en 1978; près de 4600 adultes du parasitoïde ont alors été dispersés. Le succès de #T. radiata# combiné avec la distribution de plants sains a été à l'origine de la renaissance de la culture des agrumes à l'île de la Réunion. La présence de #D. citri# en Guadeloupe a été rapportée pour la première fois en janvier 1998. Une enquête menée alors n'a révélé aucune trace de parasitisme d'insecte et seul un champignon, #Hirsutella citriformis# Speare, a prouvé, dans certaines conditions, être capable de contrôler les populations de ce psylle. à partir de l'expérience de l'île de la Réunion et en considérant le fait que la maladie du greening n'avait pas encore été détectée en Guadeloupe, une introduction de #T. radiata# à partir de l'île de la Réunion a été faite en janvier 1999. Environ 1000 adultes de #T. radiata# ont été libérés sur l'ensemble de la Guadeloupe. Actuellement, à peine plus de 1 an après le dernier lâcher, le parasitoïde est bien établi et présent dans presque tous les vergers d'agrumes où les populations de psylles ont considérablement diminué. Les caractéristiques biologiques tout à fait favorables de l'insecte jouent un grand rôle pour expliquer l'excellente efficacité de #T. radiata# dans des programmes de lutte biologique contre #D. citri#.