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Agriculture & Natural Resources Updates for Fannin & Gilmer Counties

Recently, there has been a lot of buzz in the news and a surge of interest in the Asian giant hornet, Vespa mandarinia. The coverage is not traced to any recent event. The insect was found last September 2019 in Vancouver Island (Canada) and again in December 2019 in Washington state. Fortunately, to date, this invasive insect has neither been confirmed present in the state of Georgia nor east of the Mississippi.

The Asian giant hornet is a “true” hornet and the world’s largest, ranging in size from 1.5 to slightly over 2 inches long (38-50mm). The stinger is nearly ¼-inch long and stings are extremely painful. Each year in Japan, 30-50 people die from being stung by these hornets.

The venom is not the most lethal among bees and wasps, but due to the insect’s large size, the dose is larger than any other stinging insect Americans typically encounter. Human sting deaths are biased toward individuals who are prone to anaphylactic reactions or to individuals who receive large numbers of stings. One or a few stings from an Asian giant hornet should not be life-threatening to an average individual.

While the Asian giant hornet is not necessarily aggressive towards humans, livestock or pets, they can inflict a devastating blow to honey bee colonies. There are three phases to an Asian giant hornet attacking a honey bee colony.

The first is the “hunting phase” where individual hornets will capture bees at the entrance of the colony and return to their nest to feed them to their young. The second phase is the “slaughter phase” where the hornets will mark a particular colony with a pheromone to recruit their sisters to the site. Numerous hornets will then descend upon the colony, killing all of the workers and returning to their nest with their prey.

Once the bee hive is dead, hornets enter the “occupation phase,” which involves taking over the hive, collecting pupae and larvae, and returning to their own nest to feed them to their young. In this phase the hornets will guard the hive entrance as if it were their own nest.

The aftermath of an attack is a rather gruesome site. The visible key to an Asian giant hornet attack is “decapitated” or “ripped apart” bees, and not just a pile of intact dead bees, which could be the result of pesticides, starvation or something else.

This is the hornet that incites the famous bee defensive response of “cooking” hornets to death. Asian honey bees grab an invading hornet, pile around it and raise their thoracic temperatures to the critical temperature that is lethal to wasps but tolerable to bees. Unfortunately, American honey bees, which are of European not Asiatic descent, do not have this behavior.

Again, at this time there have been no confirmed cases of this hornet’s presence in Georgia or anywhere outside of Washington state. However, it is important to note that there are other wasps and hornets that may be confused with the Asian giant hornet.

Over the past couple weeks, I’ve been contacted by many concerned Fannin and Gilmer county residents concerning wasps and hornets that are already residents of our state:

  • Cicada killers, Sphecius speciosus, size range 0.6 – 2 inches long (15 – 50mm)
  • European hornets, Vespa crabro, size range 1-1.4 inches (25-35mm)
  • Southern yellowjackets, Vespula squamosa, size range 0.5inches (12mm)
  • Baldfaced hornets, Dolichovespula maculata, size range 0.75 inches (19mm)

The Asian giant hornet and cicada killer may be similar in size but have distinctive differences in coloration. The Center for Invasive Species and Ecosystem Health have put together an “Asian Giant Hornet and its SE US Lookalikes” photographic fact sheet, which is extremely helpful for distinguishing between the different species in our state. We have it posted on our Facebook page for viewing.

At this time, we need to be vigilant but not over-reactive since, again, there is no evidence that the Asian giant hornet has journeyed East. Nonetheless, any sightings and/or disturbances to honey bee colonies should be reported immediately to your county Extension agent.

If you think you have seen an Asian giant hornet, found evidence of an attack (decapitated or ripped apart bees) or have a specimen, again, please contact your County Extension Agent immediately. Your agent will be able to collect your information and any specimens for identification. If you are not sure how to contact your local Extension office, you can call 1-800-ASK-UGA1 to find an agent near you.

For more in-depth information about the Asian giant hornet, please contact us or check out our Facebook page for informative posts on this insect.

Asian giant hornet, Photo by Allan Smith-Pardo, USDA APHIS PPQ, Bugwood.org
European hornet pinned specimen, photo by Allan Smith-Pardo, USDA APHIS PPQ, Bugwood.org