The WSDA killed about 85 hornets that were nested in an alder tree by vacuuming them out of the tree. The queen hornet was not in that group, but they do believe they killed her when they pumped carbon dioxide into the tree to kill the stragglers followed by foam sealant and shrink wrap around the tree. Sven-Erik Spichiger, an entomologist who directed the nest eradication, said it is unknown if the hornets will establish a toehold in Whatcom County and begin to migrate to other areas of the U.S. and that it still looks optimistic that the WSDA is ahead of this to keep further nesting out. (Lewis, 2020)
The Asian giant hornets (Vespa mandarinia) have found their way into the United States. Although not aggressive towards humans, these hornets present an additional threat to honey bees. The first siting in the United States was on 8 Dec 2019 by a resident in Blaine, Washington. The WSDA confirmed its identity as an Asian Hornet. This insect has not been found in Virginia or in the U.S. outside of Washington state.
While Asian hornets feast on a variety of insects, they do have an appetite for honey bees. These hornets will attack individual honey bees throughout the season; however, in the summer and early fall, they become very aggressive against the entire hive. A few hornets will attack the entire hive, then take over the hive and begin taking the brood back to their own colony to feed their young.
Asian honey bees have figured out a highly effective way to repel these hornets and eliminate the scouts before a mass attack can happen. Several hundred bees will engulf the hornet and begin to create a temperature of about 117°F for approximately 20 minutes which is lethal to the hornet. Unfortunately, this also kills some honey bees as well.
We do have European hornets that may look similar to these and do go after honey bees individually; however, the size and coloring set them apart. The main differences to tell them apart is the Asian giant hornet’s head is nearly all yellow whereas the European Hornet is reddish brown that transitions to yellow around the face. If you believe you have seen an Asian giant hornet, try to take a picture or safely collect it and send it to your county Virginia Cooperative Extension office. A list of local Extension offices is listed at https://ext.vt.edu/offices.html. There is wealth of information via the internet on Asian giant hornets. The sites used for this article were:
Lewis, S. (2020, November 01). Washington state captures two murder hornet queens alive, days after destroying first known nest. Retrieved November 01, 2020, from https://www.cbsnews.com/news/murder-hornet-washington-scientists-capture-asian-giant-hornet-queens-eradication-nest/