Asian Giant Hornet found in North America

News of the Asian Giant Hornet’s arrival in Washington state has spread a lot farther than the actual invasive insect has, and there is no evidence it has arrived in Iowa or will ever be here, according to Iowa State University Extension and Outreach specialists.

The Asian Giant Hornet (AGH), Vespa mandarinia, checks in at more than two inches, which makes it the world’s largest. It carries a painful sting and could have a serious detrimental impact on honey bee populations.

Washington State Department of Agriculture verified two reports of the AGH near Blaine, Washington in December, and a nest was discovered—and quickly destroyed—in British Columbia earlier this year. Entomologists in Washington State are on alert, and to identify AGH they are surveying with traps and relying on reports from citizens. Female AGH make their nests in the spring, but in the fall is when it is more likely that they may attack honey bee colonies.

Iowa State University and the Iowa Department of Agriculture and Land Stewardship are monitoring observations and reports about AGH to help assess the threat to Iowans.  Iowans are invited to contact the ISU Plant & Insect Diagnostic Clinic for help identifying suspect specimens. Because ISU is shut-down, contacts via email are more efficient than phone calls.

If a clear picture can be safely taken, send the image to Use extreme caution; photograph a suspect that is already dead or can be safely killed with spray or swatter.  If a picture is not available carefully record detailed observations such as size, shape and colors. 

Donald Lewis, ISU Extension entomologist, urges Iowans to watch for this and other invasive species and to report insects that seem out of the ordinary. 

“The discovery of AGH in Washington and British Columbia late in 2019 is another concern but not a reason to panic,” Lewis said.

According to Extension Program Specialist Randall Cass, it is unclear whether the AGH would find Midwestern habitats suitable, but for now, it is not the biggest worry for beekeepers. A  much more relevant concern for honey bees is the destruction of pollinator habitat.

To help bees and beekeepers and for more information on pollinators and plants to benefit them, please read Conserving Beneficial Insects with Native Plants

The arrival of the AGH is an unwanted, but not entirely unexpected development. Fortunately, there is no evidence of the presence of AGH in Iowa.  Iowans are encouraged to continue learning about AGH and to report suspicious insects.

Further reading:  Washington State Department of Agriculture.

Wasington State University Extension

Smithsonian Magazine


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