|LOONEY, CHRIS - Washington Department Of Agriculture|
|CARMAN, BRANT - Washington Department Of Agriculture|
|CENA, JENNI - Washington Department Of Agriculture|
|CICHORZ, CASSIE - Washington Department Of Agriculture|
|IYER, VIKRAM - University Of Washington|
|ORR, JESSICA - Washington Department Of Agriculture|
|ROUECHE, NATHAN - Washington Department Of Agriculture|
|SALP, KARLA - Washington Department Of Agriculture|
|UDO, LANDON - Washington Department Of Agriculture|
|VAN WESTENDORP, PAUL - British Colombia Ministry Of Agriculture And Lands|
|WILSON, TELISSA - Washington Department Of Agriculture|
|WOJAHN, RIAN - Washington Department Of Agriculture|
|SPICHIGER, SVEN-ERIK - Washington Department Of Agriculture|
Submitted to: Journal of Hymenoptera Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/17/2023
Publication Date: 3/2/2023
Citation: Looney, C., Carman, B., Cena, J., Cichorz, C., Iyer, V., Orr, J., Roueche, N., Salp, K., Serrano, J.M., Udo, L., van Westendorp, P., Wilson, T., Wojahn, R., Spichiger, S. 2023. Detection and description of four Vespa mandarinia (Hymenoptera, Vespidae) nests in western North America. Journal of Hymenoptera Research. 96:1-20. https://doi.org/10.3897/jhr.96.99307.
Interpretive Summary: The Northern Giant Hornet (NGH), Vespa mandarinia, is one of the largest hornets in the world and is known as a predator of other social insects, such as honeybees. This insect recently invaded the United States, with detections in northwestern Washington State. A group of scientists from Washington State and British Columbia conducted a survey to locate and eradicate nests of Northern Giant Hornet. This survey used standard traps and bait used in the native range of the Northern Giant Hornet, and lures developed by a scientist at the USDA laboratory in Wapato WA. There was also an online portal created to encourage community participation in trapping and detection efforts. Results of the survey allowed the researchers to capture live hornets and to use radio tags to locate four Northern Giant Hornet nests. Nests were removed and the contents within were counted and measured. Results of this study provide important information on invasive Northern Giant Hornet populations and directly resulted in the eradication of four Northern Giant Hornet nests from 2020-2021.
Technical Abstract: Vespa mandarinia Smith 1852 is a semi-specialized predator of other social Hymenoptera and one of the two largest species of Vespa. Several specimens of this predatory wasp were detected in Canada and the United States in 2019, including an entire nest that was located and destroyed on Vancouver Island, British Columbia. The Washington State Department of Agriculture and the United States Department of Agriculture collaborated to survey Washington State for V. mandarinia in 2020-2021, using traps staffed by agency personnel, collaborators from local governments and non-governmental organizations, and the general public. Trap data and public reports were used to select sites for live-trapping or net surveys, and live hornets captured in these efforts were subsequently collected and fitted with radio tags in order to locate nests. The survey ultimately led to the discovery of a V. mandarinia nest in October, 2020, and three nests in August and September, 2021. All of the nests were in Alnus rubra trees, with one just above the ground in a standing dead tree, and the other three in cavities 1.5 to ~5 meters above the ground in living trees. The number of combs in each nest varied between four and ten, cells between 418 and 1329, and total hornets per nest varied between 449 and 1474 (including immature and mature stages). Together, the four nests indicate an incipient population of V. mandarinia in the Cascadia region, and ongoing action by local, state, provincial, and federal governments, and residents of both countries, is required to avoid establishment of another exotic species in the region.