2020 Entomology virtual annual meeting

Hello everyone. On Wednesday (11th), I will present our poster by Ignacio Ruiz-Cristi, Dr. Laurence Berville, Dr. Eric Darrouzet.

The use of heat against the invasive hornet Vespa velutina: Toward a biodiversity-friendly method to destroy colonies

The Yellow-legged hornet, Vespa velutina var nigrithorax (Hymenoptera: Vespidae) is an Asian native species who had been unintentionally introduced in France around 2004 and then spread into Europe. Now that his eradication is impossible, it has been considered a species of Union concern, which requires Member states to implement control strategies.

This invasive predator has adapted well to its new environment and is nowadays a major threat to beekeeping activities, mostly by capturing returning honey bees foragers (Apis mellifera) at the beehive entrances. The overarching objective of this study was to assess the thermal resilience of the hornets to develop a green control method mimicking the effective collective defense mechanism of Apis cerana.

Indeed, defensive bee balling (“heat ball”) is particularly pronounced in the Asian honeybees A. cerana in response to hornet attacks.Here, different temperatures and thermal systems were tested on individuals according to their sex, castes, and developmental stages.

 First, two temperatures protocols were tested: instantaneous (“Flash”) versus a gradual increase (“Gradual”) to assess the resilience of the hornets. The resilience of individuals decreased significantly with the raised of temperatures. Larvae were the most resistants. Secondly, dry and steam airflow was compared. The most sudden (under 13 sec) and effective method appeared to be when steam is used. This short time frame before death could prevent hornets to react and/or flee. Further studies are necessary to determine the potential use of this method against V. velutina full colonies in natura.

Nearly 3,200 entomologists joined us for over two weeks of on-demand presentations and posters; livestream plenary and symposia; networking video chats; an online exhibit hall.