A team of researchers published a study outlining the risk of the invasive giant hornet Vespa mandarinia. In the study, the experts examined various factors that may lead to a higher risk of hornet infestation in North America. 

The hornets received a lot of attention and concern due to them killing thousands of honeybees. Risk assessments for counties in Idaho, Montana, Oregon, and Washington were conducted by the team of researchers. Vespa mandarinia, aka the Asian giant hornet, is the largest hornet species. In North America, it was first found in British Columbia, Vancouver, and later in Whatcom County, Washington

What experts think

“Asian giant hornets typically feed on insects, sap, and soft fruits, but they are known to attack and kill beehives in the late summer and early fall when developing males and future queens need protein. This behavior can affect beekeeping and pollination, and if the hornets become established, they could also displace native wasp species,” said one of the researchers.

Research showed that places with ideal temperatures are more susceptible to hornet infestation. Asian hornet queens need an environment warm enough to live through the winter, yet they also seem to be sensitive to scorching climates. The queens prefer green spaces for nest colonization, such as parks or forests. The weather conditions favored by the species is similar to its native regions’ temperature, as seen in Japan, China, and other Asian countries.

Why risk assessment is important 

The risk assessment for the research included factors such as apiary locations, forest covers, and locations of ports and freight hubs in all counties across Idaho, Montana, Oregon, and Washington. As the hornets are native to Asia, port locations that have trade shipments coming from Asian countries are most susceptible to these hornets.

The data from the study was converted into maps of places where the hornets could spread rapidly. Regions were classified as low, medium, or high risk.

“This risk assessment is important because it helps professionals who are monitoring for this invasive species to prioritize areas where the hornet is more likely to establish. When the hornet was first found in the U.S. and reported in the media, there were reports from people all around the country claiming that they were finding them. The interest and enthusiasm is great, but there are many native lookalikes that are important to the local ecosystem. Most importantly, I hope this publication will increase awareness of the threat [these] hornets can pose to essential pollinators in the U.S, a researcher stated.