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Key message: In mixed stands of Pinus pinaster and Pinus pinea, fewer insect vectors of the pinewood nematode (PWN) were captured than in pure P. pinaster stands. This finding has practical implications for PWN disease management, including the recommendation to improve the diversity of maritime pine plantations and to conserve stone pines in infected areas. Context: The PWN is an invasive species in European pine forests, being vectored by the longhorn beetle Monochamus galloprovincialis. The presence of less preferred host trees may disrupt the insect vector dispersal and slow the spread of the disease. Aims: The aim of the study was to compare the abundance of M. galloprovincialis in pure stands of Pinus pinaster, a preferred host tree, pure P. pinea stands, a less preferred host, and mixtures of these two species. Methods: We selected 20 mature pine stands varying in % P. pinaster and % P. pinea in Spain. In each stand, we installed 3 pheromone traps to catch M. galloprovincialis. We related trap catches to stand and landscape composition. Results: The level of capture of M. galloprovincialis was highest in pure P. pinaster stands and decreased with increasing proportion of P. pinea. Conclusions: The presence of stone pine mixed with maritime pine significantly reduces the local abundance of the PWN insect vector. The most plausible mechanism is that P. pinea emits odors that have a repulsive effect on dispersing beetles.

Treatment with plant elicitors can be a promising method to induce Pinus pinaster tolerance against the pinewood nematode (PWN), Bursaphelenchus xylophilus, by promoting plant antioxidant system, micronutrient accumulation and by modulating plant-associated bacterial populations. To test this hypothesis, plants were sprayed with methyl jasmonate (MeJA), salicylic acid (SA) or benzo (1,2,3)-thiadiazole-7-carbothioic acid-S-methyl ester (BTH), and evaluated until 35 days after-inoculation (dai) for: i) extent of foliar symptoms; ii) nematode density inside stem tissues; iii) proxies for oxidative damage and antioxidant activity, iv) micronutrient concentration and v) bacterial diversity. Compared with non-elicited plants, plant elicitation, particularly with BTH, significantly decreased nematodes density inside stem tissues (by 0.63-fold). Concordantly, without elicitation plant mortality reached 12.5% while no mortality was observed in elicited plants. BTH-elicited plants had significantly higher concentrations of anthocyanins and carotenoids at the end of the assay than SA-elicited and MeJA-elicited plants, which possibly contributed to the lower PWN colonization and degree of foliar symptoms observed. Accordingly, MeJA and SA led to increased lipid peroxidation at 28 dai (by 2.64- and 2.52-fold, respectively) in comparison with BTH (by 1.10-fold), corroborating its higher potential in increasing plant antioxidative response during infection. Moreover, carotenoids showed a negative correlation with nematode migration, whereas polyphenols showed a positive correlation. Elicitors also induced changes in the bacterial community of infected P. pinaster plants, increasing the diversity of specific populations. Finally, elicitors induced significant changes in micronutrients accumulation in plant tissues, namely a decrease in the concentration of B, Mn and Ni in plants treated with BTH compared to those treated with the other elicitors. Altogether, results suggest that el

Bursaphelenchus xylophilus (PWN) causes pine wilt disease (PWD), which is one of the most devastating pine diseases worldwide. Cytochrome P450 (CYP) catalyzes the biosynthetic metabolism of terpenoids and plays an important role in the modification of secondary metabolites in all living organisms. We investigated the molecular characteristics and biological functions of Bx-cyp29A3 in B. xylophilus. The bioinformatics analysis results indicated that Bx-cyp29A3 has a transmembrane domain and could dock with L(−)-carvone. The gene expression pattern indicated that Bx-cyp29A3 was expressed in 0.2, 0.4, 0.6, 0.8, and 1.0 mg/mL L(−)-carvone solutions. The Bx-cyp29A3 expression increased in a dose-dependent manner and peaked at 24 h of exposure when the L(−)-carvone solution concentration was 0.8 mg/mL. However, the gene expression peaked at 0.6 mg/mL after 36 h. Furthermore, RNA interference (RNAi) indicated that Bx-cyp29A3 played an essential role in the response to L(−)-carvone. The mortality rates of the Bx-cyp29A3 knockdown groups were higher than those of the control groups in the 0.4, 0.6, 0.8, and 1.0 mg/mL carvone solutions after 24 h of exposure or 36 h of exposure. In summary, bioinformatics provided the structural characteristics and conserved sequence properties of Bx-cyp29A3 and its encoded protein, which provided a target gene for the study of the P450 family of B. xylophilus. Gene silencing experiments clarified the function of Bx-cyp29A3 in the immune defense of B. xylophilus. This study provides a basis for the screening of new molecular targets for the prevention and management of B. xylophilus.

El nematodo de la marchitez del pino (PWN), Bursaphelenchus xylophilus, se considera uno de los organismos más dañinos de las masas forestales de Coníferas, por lo que está declarado como un organismo de cuarentena en Europa. La normativa existente para prevenir su dispersión por la comercialización de la madera de embalajes, es la Norma Internacional para Medidas Fitosanitarias No. 15 (ISPM 15), basada fundamentalmente en un tratamiento térmico. Por otro lado, la madera se trata con productos específicos contra los organismos xilófagos, y el sector industrial está cuestionando si las medidas adoptadas son suficientes y efectivas frente al PWN, por lo que el objetivo de este trabajo ha sido evaluar el efecto biocida de los principios activos más habituales presentes en las formulaciones de los protectores de la madera, frente al nematodo. Los resultados del estudio mostraron que, de los once compuestos activos estudiados, cloruro de didecil dimetilamonio (DDAC), N-butilcarbamato de 3-iodoprop-2-inilo (IPBC), hidroxicarbonato de cobre, diclofluanida, propionato de N, N-didecil-N-metil-poli (oxietil) amonio (Bardap 26) y cloruro de benzalconio (BAC) ofrecían una buena eficacia frente al PWN, ofreciendo un valor añadido a los productos químicos actualmente utilizados en la protección de la madera.

The research focus in the correlation and function of the microbial community in the pines by PWNs invaded or not, especially, the correlation between fungi and bacteria., Pine wilt disease (PWD) is a worldwide forest disease caused by pine wood nematode (PWN). In this article, we investigated the composition, organization, correlation, and function of the endophytic microbial community in Pinus massoniana field with and without PWN. Samples were taken from branches, upper, middle, and lower trunks, as well as soil, from both healthy and infected trees. The results showed that the fungal diversity of healthy pines is around 1.1 times that of infected pines, while the bacterial diversity is about 0.75 times that of infected pines at the OTUs level. An increase of the abundance of pathogenic fungus such as Saitozyma, Graphilbum, Diplodia, Candida, Pseudoxanthomonas, Dyella and Pantoea was witnessed in infected pines according to the result of LEfSe. Furthermore, Ophiostoma and saprophytic fungus such as Entomocorticium, ganoderma, tomentella, entomocorticium were exclusively prominent in infected pines, which were substantially and highly connected with other species (p < 0.05), indicating the trees’ vulnerability and making the wood blue. In healthy pines, the top three functional guilds are parasites, plant pathogens, and saprotrophs. Parasites (36.52%) are primarily found in the branches, plant pathogens (29.12%) are primarily found in the lower trunk, and saprotrophs (67.88%) are primarily found in the upper trunk of disease trees. Pines’ immunity is being eroded due to an increase in the quantity and types of diseases. PICRUSt2 research revealed that NADH or NADPH, as well as carbon-nitrogen bonds, were more abundant in healthy pines, but acid anhydrides and transferring phosphorus-containing groups were more abundant in infected pines. The shift in resin secretion lowers the tree’s potential and encourages pine wilt and mortality. In total, PWN may have disrupted the microbiological ecology and worked with the community to hasten the demise of pines.

Pine Wood Nematode Bursaphelenchus xylophilus causes Pine Wilt Disease (PWD), resulting in widespread tree mortality. This quarantine organism is necessarily vectored by Monochamus spp. pine sawyer beetles. PWD management through control of the insect vectors has been proposed. Recently, the high potential of entomopathogenic fungus Beauveria pseudobassiana for the biological control of M. galloprovincialis, the only known vector of the disease in Europe, has been shown. Several experiments were carried out aimed to develop a practical method to spread this biological control agent into the beetle population by self-dissemination tactics. Multiple funnel trap collection cups were provided with screened bottoms to effectively reduce by-catch of non-targeted beetles by 72%. Two self-release devices attached to the trap collection cups were field tested and resulted high level effective in allowing escape of trapped M. galloprovincialis adults. These devices were further developed to serve for the self-infection purpose. Two B. peudobassiana concentrations, [109] and [1010] conidia/g in talc powder, were assayed in two selfinfection devices in the laboratory. Survival time averaged was 4,9 days and dosis 2,7 mg·insect-1 was reported for the low dosage applied with thin device. Further studies testing horizontal transmission of self-infected beetles would extend these results., Bursaphelenchus xylophilus, cuyo vector es Monochamus galloprovincialis, provoca la enfermedad del marchitamiento del pino. Las estrategias de control se centran en el manejo del vector. En este trabajo se desarrolla un método de autodiseminación de Beuaveria pseudobassiana, hongo entomopatógeno de alta virulencia sobre M. galloprovincialis, que permita la infección sobre la población de este vector, consistente en un sistema mixto de autoliberación y autoinfección, de los insectos capturados en el bote colector de trampas multiembudos. Se intenta aumentar su selectividad reduciendo las capturas de especies de xilófagos no objetivo mediante modificaciones en el sistema: filtrado a través de mallas de fondo y alturas de conexión del dispositivo al bote. El sistema de malla ancha testado redujo en un 72% la captura de especies no objetivo. El dispositivo de autoliberación de Monochamus, un tubo enroscado externamente al bote colector, ha permitido la autoliberación de la totalidad de los insectos capturados. Se han determinado las características del dispositivo de autoinfección y la concentración del hongo entomopatógeno que pueden resultar adecuadas tras ensayar dos concentraciones: 1·109 y 1·1010 conidios·gramo-1 en talco y dos dispositivos. El dispositivo estrecho forrado internamente con fieltro fino y la dosis de 1·109 conidios·gramo-1 en talco han definido un tiempo promedio de vitalidad (4,9 días) y una cantidad de inóculo transmisible (2,7 mg·insecto-1) adecuado.

Pine Wood Nematode Bursaphelenchus xylophilus causes Pine Wilt Disease (PWD), resulting in widespread tree mortality. This quarantine organism is necessarily vectored by Monochamus spp. pine sawyer beetles. PWD management through control of the insect vectors has been proposed. Recently, the high potential of entomopathogenic fungus Beauveria pseudobassiana for the biological control of M. galloprovincialis, the only known vector of the disease in Europe, has been shown. Several experiments were carried out aimed to develop a practical method to spread this biological control agent into the beetle population by self-dissemination tactics. Multiple funnel trap collection cups were provided with screened bottoms to effectively reduce by-catch of non-targeted beetles by 72%. Two self-release devices attached to the trap collection cups were field tested and resulted high level effective in allowing escape of trapped M. galloprovincialis adults. These devices were further developed to serve for the self-infection purpose. Two B. peudobassiana concentrations, [109] and [1010] conidia/g in talc powder, were assayed in two selfinfection devices in the laboratory. Survival time averaged was 4,9 days and dosis 2,7 mg·insect-1 was reported for the low dosage applied with thin device. Further studies testing horizontal transmission of self-infected beetles would extend these results., Bursaphelenchus xylophilus, cuyo vector es Monochamus galloprovincialis, provoca la enfermedad del marchitamiento del pino. Las estrategias de control se centran en el manejo del vector. En este trabajo se desarrolla un método de autodiseminación de Beuaveria pseudobassiana, hongo entomopatógeno de alta virulencia sobre M. galloprovincialis, que permita la infección sobre la población de este vector, consistente en un sistema mixto de autoliberación y autoinfección, de los insectos capturados en el bote colector de trampas multiembudos. Se intenta aumentar su selectividad reduciendo las capturas de especies de xilófagos no objetivo mediante modificaciones en el sistema: filtrado a través de mallas de fondo y alturas de conexión del dispositivo al bote. El sistema de malla ancha testado redujo en un 72% la captura de especies no objetivo. El dispositivo de autoliberación de Monochamus, un tubo enroscado externamente al bote colector, ha permitido la autoliberación de la totalidad de los insectos capturados. Se han determinado las características del dispositivo de autoinfección y la concentración del hongo entomopatógeno que pueden resultar adecuadas tras ensayar dos concentraciones: 1·109 y 1·1010 conidios·gramo-1 en talco y dos dispositivos. El dispositivo estrecho forrado internamente con fieltro fino y la dosis de 1·109 conidios·gramo-1 en talco han definido un tiempo promedio de vitalidad (4,9 días) y una cantidad de inóculo transmisible (2,7 mg·insecto-1) adecuado.

Over de effecten van invasieve exoten op de biodiversiteit, de landbouw, de economie en de volksgezondheid is veel gepubliceerd, maar over de effecten op landschappen is veel minder geschreven. Terwijl exoten ook voor het landschap en de landschapsecologie een risico kunnen vormen, zoals de vele sprekende voorbeelden in dit artikel laten zien. Om de schade aan landschappen te beperken is actief beleid nodig van overheden en bedrijven, bij voorkeur preventief en op basis van het voorzorgbeginsel.

Pinewood nematode (Bursaphelenchus xylophilus) mortality was investigated after ultrasonic treatment at 20 and 40 kHz frequency. Experiments were conducted with infected small wood specimens that were ultrasonically treated for 1, 3, 5 and 7 hours and two variable temperature conditions, namely, a gradually increasing from ambient to a maximum of 70oC and a decreasing from ambient to a minimum of 5oC. The results revealed that the ultrasonic treatment itself had no significant effect on the nematode mortality at the 5oC level, while at the 70oC level, considerable nematode mortality was observed in short time periods and at 7 hours of sonic exposure it reached 100%. Therefore, certain combinations of timing and frequency of ultrasonic waves and produced heat can be effective in killing pinewood nematodes thus resulting in phytosanitized wood.

Monochamus galloprovincialis, vector del nematodo Bursaphelenchus xylophilus, es el causante en Europa de la enfermedad “marchitamiento del pino” (MP).Con su reciente introducción en Europa, la necesidad de medidas de control resulta urgente. La mejora de trampas y atrayentes aumenta las posibilidades de encontrar métodos de reducción de población del vector en zonas afectadas para erradicar la enfermedad o contener su propagación. Para evaluar la eficacia de su captura masiva, se llevaron a cabo dos experimentos de campo. En 2010 se evaluó el método de captura-marcado-recaptura (CMR) para la estimación de la abundancia poblacional, utilizando la formulación POPAN del modelo Jolly-Seber. Las estimaciones derivadas de los parámetros de mejor ajuste demostraron la validez del método. En 2013 se probaron cuatro densidades de trampas en seis parcelas de 36 hectáreas. Para evaluar la proporción de insectos capturados, se estimó en una zona contigua (260 ha) la densidad de la población local del insecto que resultó ser 82 ind/ha. El trampeo extrajo el 4,66%, 20.50%, 33.33% y 59.80% de la población usando 0.02, 0.11, 0.25 y 0.44 trampas/ha respectivamente. Una función ajustada con dichos datos muestra que el 95% de extracción de población se produciría con 0,82 trampas/ha. Estos resultados abren la posibilidad del uso de captura masiva como método de reducción de la población de M. galloprovincialis, facilitando así la contención o eventual erradicación de la enfermedad en determinadas zonas afectadas por la enfermedad.

Se aislaron tres cepas de hongos entomopatógenos en ejemplares adultos de Monochamus galloprovincialis (Olivier) (Coleptera: Cerambycidae) infectados de forma natural que resultaron pertenecer a las especies Isaria farinosa (Holmsk.) Fr., Lecanicillium attenuatum (Zare & W. Games) y Beauveria pseudobassiana (Bals.) Vuill. Esta es la primera vez que se han aislado estos hongos en ejemplares de M. galloprovincialis. En nuestros ensayos, la cepa de B. pseudobassiana (EABps 11/01-Mg) resultó ser la más virulenta para este insecto. Se investigó su capacidad de transmisión horizontal y vertical en formulación acuosa y seca. La formulación acuosa no mostró evidencias de ningún tipo de transmisión. Sin embargo, todos los insectos infectados de forma horizontal con la formulación seca murieron y su tiempo medio de vida se redujo significativamente. El número medio de mordeduras de oviposición realizadas, huevos puestos, larvas vivas 5 días tras la puesta y orificios de entrada para pupar en el xilema 6 meses después fue significativamente inferior tanto en hembras expuestas directamente al hongo como en aquellas que lo recibieron por transmisión horizontal en comparación con las hembras control, mostrando que una reducción de la progenie inducida de forma horizontal es posible. Estos resultados manifiestan el potencial de la cepa aislada de Beauveria pseudobassiana como agente regulador de la población de este insecto. A través de técnicas de autodiseminación, esta cepa podría ser usada en el control integrado del vector del nematodo de la madera del pino como una nueva herramienta para el manejo de la enfermedad del marchitamiento de los pinos.

Pinewood nematode (Bursaphelenchus xylophilus) mortality was investigated after ultrasonic treatment at 20 and 40 kHz frequency. Experiments were conducted with infected small wood specimens that were ultrasonically treated for 1, 3, 5 and 7 hours and two variable temperature conditions, namely, a gradually increasing from ambient to a maximum of 70oC and a decreasing from ambient to a minimum of 5oC. The results revealed that the ultrasonic treatment itself had no significant effect on the nematode mortality at the 5oC level, while at the 70oC level, considerable nematode mortality was observed in short time periods and at 7 hours of sonic exposure it reached 100%. Therefore, certain combinations of timing and frequency of ultrasonic waves and produced heat can be effective in killing pinewood nematodes thus resulting in phytosanitized wood.

Pinewood nematode (Bursaphelenchus xylophilus) mortality was investigated after ultrasonic treatment at 20 and 40 kHz frequency. Experiments were conducted with infected small wood specimens that were ultrasonically treated for 1, 3, 5 and 7 hours and two variable temperature conditions, namely, a gradually increasing from ambient to a maximum of 70oC and a decreasing from ambient to a minimum of 5oC. The results revealed that the ultrasonic treatment itself had no significant effect on the nematode mortality at the 5oC level, while at the 70oC level, considerable nematode mortality was observed in short time periods and at 7 hours of sonic exposure it reached 100%. Therefore, certain combinations of timing and frequency of ultrasonic waves and produced heat can be effective in killing pinewood nematodes thus resulting in phytosanitized wood.

Pinewood nematode (Bursaphelenchus xylophilus) mortality was investigated after ultrasonic treatment at 20 and 40 kHz frequency. Experiments were conducted with infected small wood specimens that were ultrasonically treated for 1, 3, 5 and 7 hours and two variable temperature conditions, namely, a gradually increasing from ambient to a maximum of 70oC and a decreasing from ambient to a minimum of 5oC. The results revealed that the ultrasonic treatment itself had no significant effect on the nematode mortality at the 5oC level, while at the 70oC level, considerable nematode mortality was observed in short time periods and at 7 hours of sonic exposure it reached 100%. Therefore, certain combinations of timing and frequency of ultrasonic waves and produced heat can be effective in killing pinewood nematodes thus resulting in phytosanitized wood.

Monochamus galloprovincialis, vector del nematodo Bursaphelenchus xylophilus, es el causante en Europa de la enfermedad “marchitamiento del pino” (MP).Con su reciente introducción en Europa, la necesidad de medidas de control resulta urgente. La mejora de trampas y atrayentes aumenta las posibilidades de encontrar métodos de reducción de población del vector en zonas afectadas para erradicar la enfermedad o contener su propagación. Para evaluar la eficacia de su captura masiva, se llevaron a cabo dos experimentos de campo. En 2010 se evaluó el método de captura-marcado-recaptura (CMR) para la estimación de la abundancia poblacional, utilizando la formulación POPAN del modelo Jolly-Seber. Las estimaciones derivadas de los parámetros de mejor ajuste demostraron la validez del método. En 2013 se probaron cuatro densidades de trampas en seis parcelas de 36 hectáreas. Para evaluar la proporción de insectos capturados, se estimó en una zona contigua (260 ha) la densidad de la población local del insecto que resultó ser 82 ind/ha. El trampeo extrajo el 4,66%, 20.50%, 33.33% y 59.80% de la población usando 0.02, 0.11, 0.25 y 0.44 trampas/ha respectivamente. Una función ajustada con dichos datos muestra que el 95% de extracción de población se produciría con 0,82 trampas/ha. Estos resultados abren la posibilidad del uso de captura masiva como método de reducción de la población de M. galloprovincialis, facilitando así la contención o eventual erradicación de la enfermedad en determinadas zonas afectadas por la enfermedad.

Se aislaron tres cepas de hongos entomopatógenos en ejemplares adultos de Monochamus galloprovincialis (Olivier) (Coleptera: Cerambycidae) infectados de forma natural que resultaron pertenecer a las especies Isaria farinosa (Holmsk.) Fr., Lecanicillium attenuatum (Zare & W. Games) y Beauveria pseudobassiana (Bals.) Vuill. Esta es la primera vez que se han aislado estos hongos en ejemplares de M. galloprovincialis. En nuestros ensayos, la cepa de B. pseudobassiana (EABps 11/01-Mg) resultó ser la más virulenta para este insecto. Se investigó su capacidad de transmisión horizontal y vertical en formulación acuosa y seca. La formulación acuosa no mostró evidencias de ningún tipo de transmisión. Sin embargo, todos los insectos infectados de forma horizontal con la formulación seca murieron y su tiempo medio de vida se redujo significativamente. El número medio de mordeduras de oviposición realizadas, huevos puestos, larvas vivas 5 días tras la puesta y orificios de entrada para pupar en el xilema 6 meses después fue significativamente inferior tanto en hembras expuestas directamente al hongo como en aquellas que lo recibieron por transmisión horizontal en comparación con las hembras control, mostrando que una reducción de la progenie inducida de forma horizontal es posible. Estos resultados manifiestan el potencial de la cepa aislada de Beauveria pseudobassiana como agente regulador de la población de este insecto. A través de técnicas de autodiseminación, esta cepa podría ser usada en el control integrado del vector del nematodo de la madera del pino como una nueva herramienta para el manejo de la enfermedad del marchitamiento de los pinos.

The Pine Wood Nematode (PWN) Bursaphelenchus xylophilus is a severe forest pathogen in countries where it has been introduced and is considered a worldwide quarantine organism. In this study, protein markers for differentiating populations of this nematode were identified by studying differences among four selected Iberian and one American population. These populations were compared by quantitative proteomics (iTRAQ). From a total of 2860 proteins identified using the public database from the B. xylophilus genome project, 216 were unambiguous and significantly differentially regulated in the studied populations. Comparisons of their pairwise ratio were statistically treated and supported in order to convert them into discrete character states, suggesting that 141 proteins were not informative as population specific markers. Application of the Character Compatibility methodology on the remaining 75 proteins (belonging to families with different biological functions) excludes 27 which are incompatible among them. Considering only the compatible proteins, the method selects a subset of 30 specific unique protein markers which allowed the compared classification of the Iberian isolates. This approach makes it easier search for diagnostic tools and phylogenetic inference within species and populations of a pathogen exhibiting a high level of genetic diversity.

Les invasions biologiques se sont intensifiées au cours des dernières décennies en raison d'une accélération des échanges commerciaux. Ces invasions représentent une menace pour les écosystèmes et de nombreuses activités anthropiques, il est donc crucial de comprendre les mécanismes qui les sous-tendent afin de mieux prévoir et limiter leurs impacts. Dans cette thèse, j'aborde la question du potentiel dispersif d'espèces natives et non natives impliquées dans une association phorétique nouvellement formée. En particulier, je me focalise sur le cas de l'association entre un nématode invasif ravageur des pinèdes, le nématode du pin (Bursaphelenchus xylophilus) et son insecte vecteur endémique en Europe (Monochamus galloprovincialis). J'ai tout d'abord étudié les flux de gènes de l'insecte vecteur seul afin d'identifier les barrières à sa dispersion. J'ai ensuite simulé l'expansion spatiale du couple nématode-vecteur à l'aide d'un modèle de dispersion, en intégrant l'effet synergique de cette nouvelle association. Les résultats obtenus au cours de cette thèse montrent qu'il existe un important potentiel de dispersion du nématode invasif en Europe par le biais de cette association phorétique. En revanche, certains paramètres de l'environnement tels que les reliefs et les températures basses qui leur sont associées, ainsi que les fortes densités en pins constituent des barrières à la dispersion du vecteur et donc des obstacles potentiels à l'expansion du nématode invasif. Au-delà des apports relatifs au modèle d'étude, cette thèse a conduit au développement de plusieurs méthodes pouvant être adaptées à d'autres cas d'associations phorétiques nouvelles et, par extension, contribuer à la compréhension de la dispersion des espèces au sein de ces systèmes complexes et peu étudiés.

Les invasions biologiques se sont intensifiées au cours des dernières décennies en raison d'une accélération des échanges commerciaux. Ces invasions représentent une menace pour les écosystèmes et de nombreuses activités anthropiques, il est donc crucial de comprendre les mécanismes qui les sous-tendent afin de mieux prévoir et limiter leurs impacts. Dans cette thèse, j'aborde la question du potentiel dispersif d'espèces natives et non natives impliquées dans une association phorétique nouvellement formée. En particulier, je me focalise sur le cas de l'association entre un nématode invasif ravageur des pinèdes, le nématode du pin (Bursaphelenchus xylophilus) et son insecte vecteur endémique en Europe (Monochamus galloprovincialis). J'ai tout d'abord étudié les flux de gènes de l'insecte vecteur seul afin d'identifier les barrières à sa dispersion. J'ai ensuite simulé l'expansion spatiale du couple nématode-vecteur à l'aide d'un modèle de dispersion, en intégrant l'effet synergique de cette nouvelle association. Les résultats obtenus au cours de cette thèse montrent qu'il existe un important potentiel de dispersion du nématode invasif en Europe par le biais de cette association phorétique. En revanche, certains paramètres de l'environnement tels que les reliefs et les températures basses qui leur sont associées, ainsi que les fortes densités en pins constituent des barrières à la dispersion du vecteur et donc des obstacles potentiels à l'expansion du nématode invasif. Au-delà des apports relatifs au modèle d'étude, cette thèse a conduit au développement de plusieurs méthodes pouvant être adaptées à d'autres cas d'associations phorétiques nouvelles et, par extension, contribuer à la compréhension de la dispersion des espèces au sein de ces systèmes complexes et peu étudiés.

The pine wilt disease (PWD) is caused by the pine wood nematode (PWN) Bursaphelenchus xylophilus, a microscopic worm that feeds off the host´s xylem cells and, under favourable edaphic-climatic conditions, is able to kill an adult tree in less than four months. It has become a devastating pest for pine forests leading to the yearly loss of thousands of pine trees worldwide, including P. pinaster plantations in Portugal. In the Iberian Peninsula it has, however, not yet significantly affected other Pinus species in the field, namely P. pinea, leading to the hypothesis that Pinus spp. have differential mechanisms that determine host susceptibility to the nematode. In the current presentation I will highlight some of the concerted Iberian efforts that have been undertaken at “Universidade Católica”, with collaboration with “Universidad de Extremadura” and “Misión Biológica de Galicia” (CSIC) in order to understand some of the anatomical, physiological, biochemical, and molecular aspects that underlie host susceptibility within different Pinus species. Controlled inoculations and an integrated analysis of several host traits allowed us to conclude that aspects related to disease resistance may be linked to stem anatomical traits, to the differential expression of specific genes, to the release of particular volatile organic compounds (VOCs), and to the constitutive and induced expression of defence molecules.

Le nématode du pin Bursaphelenchus xylophilus, originaire des Etats-Unis, est responsable de dépérissements massifs dans les forêts de pin des pays où il a été introduit. Il utilise comme vecteur un insecte du genre Monochamus, notamment M. galloprovincialis en Europe. L'objectif de cette thèse est de fournir des informations concernant les capacités de dispersion de ce coléoptère afin de mieux prédire le risque d'invasion. A l'aide d'expériences en manège de vol, nous avons montré que les adultes émergents, encore immatures, sont déjà en mesure de maintenir des vols soutenus. Ils peuvent parcourir une distance d'environ 500m par jour et les capacités de vol augmentent avec la prise de poids pendant la phase de maturation sexuelle. Il n'existe pas de compromis d'allocation de l'énergie entre fonctions de dispersion et de reproduction pendant cette période et nous proposons de qualifier ces insectes de "income breeder" et "capital disperser". A l'état mature M. galloprovincialis est capable de voler un total de 16km, avec des vols individuels d'environ 1km; ces performances augmentent avec l'âge et le poids des insectes. Le maintien des capacités de vol tout au long de la vie adulte de M. galloprovincialis conduit à proposer que les distances potentiellement parcourues dépendent surtout de la longévité de l'insecte. Dans une expérience d'élevage en conditions contrôlées nous avons montré que la vie adulte dure au moins 4 mois, augmentant quand les fluctuations thermiques sont atténuées. Ces résultats ont des implications pour la gestion de B. xylophilus en Europe puisqu'ils démontrent que la méthode d'éradication par coupe rase sur un rayon de 500m est probablement inopérante.

Le nématode du pin Bursaphelenchus xylophilus, originaire des Etats-Unis, est responsable de dépérissements massifs dans les forêts de pin des pays où il a été introduit. Il utilise comme vecteur un insecte du genre Monochamus, notamment M. galloprovincialis en Europe. L'objectif de cette thèse est de fournir des informations concernant les capacités de dispersion de ce coléoptère afin de mieux prédire le risque d'invasion. A l'aide d'expériences en manège de vol, nous avons montré que les adultes émergents, encore immatures, sont déjà en mesure de maintenir des vols soutenus. Ils peuvent parcourir une distance d'environ 500m par jour et les capacités de vol augmentent avec la prise de poids pendant la phase de maturation sexuelle. Il n'existe pas de compromis d'allocation de l'énergie entre fonctions de dispersion et de reproduction pendant cette période et nous proposons de qualifier ces insectes de "income breeder" et "capital disperser". A l'état mature M. galloprovincialis est capable de voler un total de 16km, avec des vols individuels d'environ 1km; ces performances augmentent avec l'âge et le poids des insectes. Le maintien des capacités de vol tout au long de la vie adulte de M. galloprovincialis conduit à proposer que les distances potentiellement parcourues dépendent surtout de la longévité de l'insecte. Dans une expérience d'élevage en conditions contrôlées nous avons montré que la vie adulte dure au moins 4 mois, augmentant quand les fluctuations thermiques sont atténuées. Ces résultats ont des implications pour la gestion de B. xylophilus en Europe puisqu'ils démontrent que la méthode d'éradication par coupe rase sur un rayon de 500m est probablement inopérante.

Monochamus-boktorren komen in en buiten Europa voor in bossen. De kevers doen zich hier tegoed aan naaldbomen. In Nederland zijn vijf Monochamus-soorten aangetroffen, die alle door versleping op onverwachte plekken kunnen opduiken. Eén soort – de dennen-geelschildboktor (M. galloprovincialis) – heeft een populatie in de duinen bij Schoorl en leeft daar een rustig bestaan, waarbij van schade aan dennen of een vergroting van het areaal geen sprake lijkt.

Following a request from European Commission, the PLH Panel examined the comments of the Portuguese plant health authorities on a previous EFSA opinion with regard to pine wood nematode (PWN) and Pinus pinea and a report on PWN surveys in Portugal. Regarding the comment, based on behavioural responses of PWN to CO2 and to ß-myrcene, that Monochamus galloprovincialis can feed on P. pinea without implying PWN infestation, the Panel noted the uncertainties on how chemical attraction influences the exit of PWN from the vector. The Panel agreed that P. pinea is not a preferred breeding host of M. galloprovincialis, but it noted the evidence from Italy of breeding of M. galloprovincialis in fallen woods of P. pinea, suggesting P. pinea to be an occasional host. The Panel agreed that, although pathogenicity of PWN has been recorded on P. pinea in inoculation experiments on small plants, this does not necessarily relate to pathogenicity on larger trees in the field. The additional information on Portuguese PWN surveys is not sufficient to conclude that P. pinea is resistant to PWN. The Panel also noted that asymptomatic infestations by PWN are well known in other areas, and pine species considered tolerant to PWN could still maintain it at low levels in restricted parts of a tree. The Panel concluded that there is high uncertainty concerning the classification of the risk of spread of PWN with plants and wood of P. pinea, owing to the scarcity of information on the interaction of M. galloprovincialis, PWN and P. pinea, as well as on the field resistance of P. pinea to PWN. Owing to high uncertainty related to the host potential of P. pinea, more studies on the transmission of PWN at feeding wounds and on its survival in trees and wood of P. pinea are needed.

Het Instituut voor Landbouw- en Visserijonderzoek (ILVO) en de Université Libre de Bruxelles (ULB) onderzoeken of de zeer schadelijke “dennenhoutnematode” (dennenaaltje, Bursaphelenchus xylophilus) ook in ons land voorkomt. Het aaltje kan dennenbomen parasiteren en doden. De wetenschap weet dat de uitheemse (Noord-Amerikaanse of Oost-Aziatische) Monochamus drager is of kan zijn van het gevreesde aaltje.

In the frame of the EU project PRATIQUE (KBBE-2007-212459 Enhancements of pest risk analysis techniques) a suite of models was developed to support the quantitative assessment of spread in pest risk analysis. This dataset contains the model codes (R language) for the four models in the suite. Three versions of the code are provided, differing in grid and spatial extent: (1) a decimal degree grid version for Europe; (2) a metric grid version for Europe and (3) a decimal degree grid version for other parts of the world. Usage of the code is described in the “Tutorial on the generic spread models“. Case studies were conducted with the decimal degree version, using European maps of climate suitability and presence of host or habitat for seven species: (1) Diabrotica virgifera virgifera, (2) Anoplophora chinensis, (3) Anoplophora glabripennis, (4) Eichhornia crassipes; (5) Meloidogyne enterolobii, (6) Bursaphelenchus xylophilus / Monochamus, (7) Gibberella circinata. See the “Description of case studies“ for details. Further background can be found in the publication: Robinet C, Kehlenbeck H, Kriticos DJ, Baker RHA, Battisti A, Brunel S, Dupin M, Eyre D, Faccoli M, Ilieva Z, Kenis M, Knight J, Reynaud P, Yart A, van der Werf W (2012) A suite of models to support the quantitative assessment of spread in pest risk analysis. PLoS ONE

The European Commission requested the Panel on Plant Health to deliver a scientific opinion on the phytosanitary risk of plants (other than fruits and seeds) of Pinus pinea and of the genera Chamaecyparis, Cryptomeria and Juniperus for the spread of pine wood nematode (PWN) via movement of infested plants or untreated plant products or by supporting natural spread of PWN in conjunction with European species of the vector. The Panel analysed the data submitted by Portugal regarding surveys on the Tróia Peninsula where P. pinaster and P. pinea co-occur, and the related laboratory results of Naves et al. (2006) on feeding and oviposition preferences of Monochamus galloprovincialis. The Panel also undertook a comprehensive review of the literature. The zero infestation of PWN recorded on P. pinea on the Tróia Peninsula was not significantly different from the result for P. pinaster, because of the small P. pinea sample. Hence, the conclusion that P. pinea is not a host plant for PWN is not supported by the data submitted, principally because of low statistical confidence arising from the few P. pinea trees present. Moreover, the limited presence of P. pinea in the study areas means that the results are representative neither of the Tróia Peninsula nor of other parts of Portugal. Naves et al. (2006) recorded some oviposition by M. galloprovincialis on P. pinea, but less than on other hosts. No differences in feeding of M. galloprovincialis on P. pinaster and P. pinea were detected, thus potentially allowing PWN transmission to trees by this route. The available information regarding the genera Chamaecyparis, Cryptomeria and Juniperus as potential hosts of Monochamus spp. and PWN suggests overall a low susceptibility to PWN or its vectors; the uncertainty concerning PWN is high and would require supplementary research.

Plant parasitic nematodes are the most destructive group of plant pathogens worldwide and their control is extremely challenging. Plant Essential oils (EOs) and their constituents have a great potential in nematode control since they can be developed for use as nematicides themselves or can serve as model compounds for the development of derivatives with enhanced activity. This study reviews the plant EOs evaluated as potential nematicides and their toxic effects against pinewood nematode (Bursaphelenchus xylophilus) and root-knot nematodes (Meloidogyne spp.). Additionally, the nematicidal activity to M. javanica of several EOs from Spanish aromatic plants and their components is described.

CONCLUSIES Monochamus sutor is in Nederland bekend van zeventien exemplaren, waarvan algemeen wordt aangenomen dat deze zijn geïmporteerd. De meest recente stamt uit 1961. De dichtstbijzijnde populatie bevindt zich in het zuidoosten van Rheinland-Pfalz in Duitsland. Het lijkt vooralsnog niet waarschijnlijk dat de soort op eigen kracht in Nederland terecht komt. Monochamus galloprovincialis is in Nederland van zes waarnemingen van ingevoerde exemplaren bekend, de recentste uit 2009. Daarnaast bevindt zich tenminste sinds de eerste helft van de twintigste eeuw een populatie in de duinen bij Bergen en Schoorl (Noord-Holland). Buiten de duinen van Schoorl en Bergen zijn er geen populaties van Monochamus-soorten uit Nederland bekend. De aanwezigheid van een populatie M. galloprovincialis bij Bergen en Schoorl toont aan dat Nederland in ieder geval klimatologisch voor deze soort geschikt is. Gezien de lage trefkans van de soort is het echter niet uit te sluiten dat er op andere plekken in Nederland populaties aanwezig zijn. Potentiële vindplaatsen zijn grote opstanden van dennen (M. galloprovincialis) of grote opstanden van sparren (M. sutor). Zelfs indien beide soorten niet op eigen kracht vanuit het buitenland Nederland weten te bereiken, dan nog zouden ze via import in ons land terecht kunnen komen. Hierbij is de import met plantmateriaal het waarschijnlijkste hoewel de waarneming in 2009 van een exemplaar van M. galloprovincialis bij een kuikenmestbedrijf te Ede laat zien dat ze ook op andere wijze ingevoerd kunnen worden. De vijftien, in de zomer van 2009, bij Bergen en Schoorl gevangen exemplaren van M. galloprovincialis bleken geen Bur

CONCLUSIES Monochamus sutor is in Nederland bekend van zeventien exemplaren, waarvan algemeen wordt aangenomen dat deze zijn geïmporteerd. De meest recente stamt uit 1961. De dichtstbijzijnde populatie bevindt zich in het zuidoosten van Rheinland-Pfalz in Duitsland. Het lijkt vooralsnog niet waarschijnlijk dat de soort op eigen kracht in Nederland terecht komt. Monochamus galloprovincialis is in Nederland van zes waarnemingen van ingevoerde exemplaren bekend, de recentste uit 2009. Daarnaast bevindt zich tenminste sinds de eerste helft van de twintigste eeuw een populatie in de duinen bij Bergen en Schoorl (Noord-Holland). Buiten de duinen van Schoorl en Bergen zijn er geen populaties van Monochamus-soorten uit Nederland bekend. De aanwezigheid van een populatie M. galloprovincialis bij Bergen en Schoorl toont aan dat Nederland in ieder geval klimatologisch voor deze soort geschikt is. Gezien de lage trefkans van de soort is het echter niet uit te sluiten dat er op andere plekken in Nederland populaties aanwezig zijn. Potentiële vindplaatsen zijn grote opstanden van dennen (M. galloprovincialis) of grote opstanden van sparren (M. sutor). Zelfs indien beide soorten niet op eigen kracht vanuit het buitenland Nederland weten te bereiken, dan nog zouden ze via import in ons land terecht kunnen komen. Hierbij is de import met plantmateriaal het waarschijnlijkste hoewel de waarneming in 2009 van een exemplaar van M. galloprovincialis bij een kuikenmestbedrijf te Ede laat zien dat ze ook op andere wijze ingevoerd kunnen worden. De vijftien, in de zomer van 2009, bij Bergen en Schoorl gevangen exemplaren van M. galloprovincialis bleken geen Bursaphelenchus xylophilus bij zich te dragen en er kan met redelijke zekerheid worden aangenomen dat deze populatie vrij is van deze nematode. Tijdens het in 2009 bij Schoorl uitgevoerde veldwerk bleek dat de WitaPrall Bark Beetle Trap (WBBT) in combinatie met het feromoon Gallowit geschikt is voor het inventariseren van M. galloprovinc

Pine wilt is a disease of pine (Pinus spp.) caused by the pinewood nematode, Bursaphelenchus xylophilus. The pinewood nematode is native to North America and is not considered a primary pathogen of native pines, but is the cause of pine wilt in some non-native pines. In countries where the pinewood nematode has been introduced, such as Japan and China, pine wilt is an important non-native disease.

マツノザイセンチュウ（Bursaphelenchus xylophilus）からSDS/フェノール・塩化セシウム法によりRNAを抽出し，ポリ（A）＋RNAを精製した．さらにこのマツノザイセンチュウに由来するポリ（A）＋RNAが鋳型活性を持っことを確かめた．これを用いてマツノザイセンチュウ病の病原物質の候補であるセルラーゼの起源が証明される可能性がある．, Total RNA was successufully isolated from the pine wood nematodes, Bursaphelenchus xylophilus, by the SDS-phenol/CsCl method. Poly(A)+ RNA was purified from the RNA, and was shown to have template activity. Since poly(A)+ RNA is produced by eucaryotes, including the pine wood nematode, the template active poly(A)+ RNA of the pine wood nematodes can be used to clarify the origin of cellulase in the pine wilt disease.

Er bestaat een risico op introductie van Aziatische boktorren. Deze exoten kunnen voor gevaarlijke situaties zorgen bij straatbomen en grote schade aanrichten in de groene ruimte. Om voorbereid te zijn op mogelijke introducties van deze organismen worden de mogelijkheden van staminjectie onderzocht als bestrijdingsmaatregel tegen genoemde boktorren