Electrical traps, so called harps, efficient and selective against Vespa velutina workers predating on hives.

The introduction in Europe of the yellow-legged hornet Vespa velutina in 2004 has been the most successful invasion of an eusocial vespid, with dramatic effects on honeybees. Whereas an eradication is almost impossible in mainland, attacks and pressure on beehives are arising. Here we study the efficiency of non-attractive interception traps, so-called electric harps, by following a recent work using the same type of device which took place in Galicia (Spain). We used eight beehives separated in two groups, four with electric harps and two without them. Electric harps captured a huge amount of individuals from V. velutina and other species. Thus, beehives with electric harps are expected to experiment less pressure than those without them. Our study is a first step which should motivate further studies on this system. It however illustrates the efficiency and high selectivity of electric harps in protecting beehives, and can be used to understand foraging periods of hornets. Here we conclude that, owing to their low impact on biodiversity, such interception non baited traps provide a good protection of hives as tested in small apiaries, and we advise beekeepers to use these traps for hives situated in areas with high predation pressure. [ABSTRACT FROM AUTHOR]