D3494: Trapping effectiveness for greater banded hornet, Vespa tropica L. (Hymenoptera: Vespidae), on Guam

Hornets in the genus Vespa are large predatory wasps that feed on a variety of social Hymenoptera including paper wasps and honey bees. There are a total of 22 species of hornets in the genus Vespa, all of which are indigenous to Asia. There have been three new recent incursions of Vespa in the United States and its territories. One of these incursions is the establishment of the greater banded hornet (GBH), Vespa tropica L., in a residential area in 2016 on the island of Guam.  Fifty-five honey bee colonies have since been lost on Guam to hornet depredation since its introduction. GBH predation has forced local beekeepers to develop entrance excluders, hardware cloth barriers and traps to exclude GBH from colonies within apiaries. This study evaluated the effectiveness of a variety of traps and baits in capturing GBH in four attacked apiaries. Seven trap-bait combinations were compared and catch rates calculated between August 2023 and May 2024. Only one trap-bait combination consisting of squeezed honeycomb contained within a cage of 6.35mm (1/4 in) mesh hardware cloth successfully attracted and retained GBH. Better GBH trapping methods will be required should GBH become established in CONUS.