Search results for "prédateur"
showing 6 items of 6 documents
Integrative taxonomy demonstrates the unexpected synonymy between two predatory mite species: Cydnodromus idaeus and C. picanus (Acari: Phytoseiidae)
2011
Contact: tixier@supagro.inra.fr; Species of the mite family Phytoseiidae are well known as predators of mite pests all over the world. Their identification is thus of great interest for biological control. The specimens examined in this study belong to the species Cydnodromus idaeus (described from Brazil) and C. picanus (described from Chile). They were collected together on the same plant in Argentina. These species are mainly differentiated by the presence/absence of the dorsal solenostomes (gland openings) gd2. Some morphometric differences were observed between the Argentinian specimens and the type material of C. idaeus and C. picanus; however, they were not sufficient to support a sp…
Olfactory attraction of the hornet Vespa velutina to honeybee colony odors and pheromones.
2014
19 pages; International audience; Since the beginning of the last century, the number of biological invasions has continuously increased worldwide. Due to their environmental and economical consequences, invasive species are now a major concern. Social wasps are particularly efficient invaders because of their distinctive biology and behavior. Among them, the yellow-legged hornet, Vespa velutina, is a keen hunter of domestic honeybees. Its recent introduction to Europe may induce important beekeeping, pollination, and biodiversity problems. Hornets use olfactory cues for the long-range detection of food sources, in this case the location of honeybee colonies, but the exact nature of these c…
Anxiété et manipulation parasitaire chez un invertébré aquatique : approches évolutive et mécanistique
2020
Trophically transmitted parasites induce changes in their host’s phenotype. These changes are supposed to increase transmission probability to definitive hosts through the predation of intermediate hosts. This phenomenon is known as ‘parasite manipulation’ has been hypothesized to be an adaptive trait of parasites for a long time. As manipulation involves predator-prey interactions, it is therefore necessary to understand how antipredatory behaviours are modulated by exogenous (predation pressure) and endogenous (infection, emotional state) factors. We tried to go into this phenomenon in depth, in amphipods, by responding toseveral questions : (1) what is the extent of the multidimensionali…
Characterization of trophic links in an agrosystem : weed seed predation by carabid beetles
2012
Agroecology gives evidence of new perspectives in agriculture, and open doors for alternative weed management approaches through different regulation mechanisms. Seed predation is one of them, and the interest is growing to deepen knowledge, relative to this process. This Phd work aims (i) to describe weed seed predation, the dominant carabid predators and the available resource at a local scale in a common crop (winter wheat); (ii) to study predation profiles of main predators, and the pair-wise correlations between the biological components of the system; (iii) to bring new insights regarding potential regulation of weed communities, through seed predation by carabid beetles. Complementar…
Les impacts du campagnol terrestre sur les systèmes fourragers : le cas de l’élevage bovin allaitant en Bourgogne
2014
EAAgroSupECOLDUR; Do vole outbreaks have the same effects on suckler beef farms in Burgundy as they do on daily farms in Auvergne and Franche-Comte? Semi-structured interviews were carried out with 19 farmers from Burgundy who had been affected by a water vole outbreak in 2011. The results indicate that, just like farmers in Auvergne and Franche-Comte, farmers in Burgundy witnessed a decrease in forage quantity and quality. Farmers used diverse measures to deal with the outbreak (e.g., avoidance strategies or the use of bromadiolone). Farmers that described water voles as pests were more likely to have used bromadiolone, while those who described water voles in morphological terms or in ter…
Les coléoptères carabiques sont-ils plus sélectifs face à un risque de prédation ou de compétition ?
2017
Le temps nécessaire à l’évaluation et à l’acceptation d’une ressource est directement lié à sa qualité. Ainsi, les individus s’approvisionnant dans un milieu naturel font face à un compromis entre vitesse de prise de décision et qualité de la ressource (speed-accuracy trade-off). Si la qualité de la ressource est un élément important pour favoriser sa valeur adaptative (fitness), le temps nécessaire au processus de décision n’est plus disponible pour d’autres tâches essentielles comme la vigilance. De plus, une prise de décision trop longue expose aussi les individus à un risque plus important de compétition et de perte d’opportunités. On s’attend à ce que des animaux confrontés à un risque…