Predation pressure dynamics study of the recently introduced honeybee killer Vespa velutina: learning from the enemy

Abstract

Following the recent introduction of Vespa velutina into France, an increase in predation on domestic honeybees, Apis mellifera, has resulted from the dispersion of this hornet across the country. We aimed at providing its predation pressure dynamics at bee hives in two sites by using food traps that could be used as a comparison in future years. The number of trapped and chasing hornets in each apiary was correlated. Predation lasted 5 months on our two sites; 916 and 1,894 hornets were trapped on each site, respectively. Predation at bee hives was found to be affected by wind speed and by the seasonal effect of temperature and humidity. We also show that V. velutina queens and males were present during unusual periods in our traps, which may be significant to understanding their life cycle. These results are discussed with reference to the biology of other Vespine species. This study represents the first monitoring of V. velutina predation pressure dynamics in France. It constitutes an initial database for pest management and suggests ways of protecting bee hives.