PESTROPHIC (SAVE / BioGeCO)

Contamination level and behavioral response of the Asian hornet Vespa velutina exposed to pesticides in different environmental conditions.

The impact of pesticides is usually studied from the perspective of biodiversity loss. However, the processes by which they really impact the ecosystem are partially investigated and especially the accumulation of pesticide in trophic networks is of real concern.

The biomagnification process of toxic compounds from preys to predators is mostly unstudied. Although the relationship between pesticides, honey bees, and health has been widely studied in the last decade, nothing is known on the predators of the upper trophic chain level that incorporate honeybees in their diet. In this exploratory project, we will focus on social honeybees, Apis mellifera, which are known to accumulate sublethal doses of pesticides and are intensively predated by the invasive yellow-legged Asian hornet, Vespa velutina, since its introduction in southwest France a decade ago. Taking advantage of this particular prey-predator system, we will study for the very first time, the bioaccumulation of different pesticides commonly used in three different environments all belonging to agroecosystems (vineyard, forest, farmland) in an insect predator species. Honeybees from colonies in the hunting range of V. velutina and wild nests of V. velutina will be detected with the recently developed radio-telemetry technique and sampled in the different landscapes. Individuals (larvae and adults) will be extracted from the colonies for individual pesticide residue analysis. From the same nests contaminated with sub-lethal concentrations of pesticides, the foraging behavior of V. velutina will be studied with Radio Frequency Identification. The growth of the larvae will be measured and the behavior of contaminated foundresses analyzed. The reproductive abilities as well as the male fertility will also be investigated in individuals contaminated or not with pesticides.

Project leader : Denis Thiery (SAVE) - MAIL
Partners : BioGeCo, UR Œnologie, Centre d'Etudes Biologiques de Chizé
© Photo : Frelon Vespa velutina marqué d’une puce RFID d’identification accueilli par un congénère lorsqu’il ramène une proie à son nid.
Copyright INRA UMR Save, cliché Alain Girard.