What You Need to Know About the Asian Giant Hornet

There’s a lot of hype going around about the “murder hornet.”

There's been a lot of buzz about the Asian giant hornet lately. Dubbed the "murder hornet" by a national news outlet, this slang name has been giving some people a bit of a fright. With a term like that, it's no surprise! The truth about this potentially invasive species, however, is far less scary. So, let's set the record straight by looking at some facts.

1. "Murder hornet" is just a catchphrase – and not a very good one at that.

Its common name is the Asian giant hornet (Vespa mandarinia)—and "giant" is no exaggeration. Averaging 1½ to 2 inches in length, this insect has rightfully earned its place as the largest hornet in the world. To put that in perspective, the Asian giant hornet is about the same size as a double-A battery. That's about three times the size of the Western honeybee, also known as the European honeybee. Add a 3-inch wingspan and ¼-inch stinger, and it's hardly surprising that the Asian giant hornet has been known to raise both eyebrows and questions.

2. The largest hornet in the world is actually a wasp native to Asia.

The Asian giant hornet, which belongs to the same scientific order (Hymenoptera) as ants and bees, is considered a wasp. All hornets are wasps, but not all wasps are hornets. The biggest difference is size: Hornets are larger and more robust, whereas wasps are smaller and have a pinched-in waist. Coloring varies, too, depending on species, though most wasps are black or have various colored markings. The color of the Asian giant hornet is rather distinctive, with a yellow-orange head, bulging black eyes, and a prominent black- or brown-and-yellow striped belly.

Like other wasps, hornets, and bees, Asian giant hornet form colonies that consist of a queen, workers, and juveniles. It's up to the queen to establish the colony, and her preferred nesting location is underneath the ground in an existing cavity, such as an abandoned mole burrow. This makes finding Asian giant hornet nests more difficult and labor intensive than, say, locating a paper wasp nest that's clinging to an eave or gutter.

3. In the United States, the Asian giant hornet only has been spotted in Washington state.

The Asian giant hornet is not officially established here in the U.S. To be clear, they do not occur here naturally at all. There have been less than a handful of confirmed sightings in all of North America as of spring 2020, and those have been in British Columbia, Canada, and Washington state (which has only one confirmed sighting). It's highly unlikely that you will encounter an Asian giant hornet in this country anytime soon, especially if you live east of Washington.

4. There's no evidence that the "murder hornet" is any more of a threat to humans than other hornets are.

In spite of its nickname, the Asian giant hornet is not out to get humans. It is no more a "murderer" than any other wasp or hornet found in the United States. Like other wasps and hornets, the Asian giant hornet feeds on multiple insects. It also feeds on plant sap, which makes it an omnivore more than anything else.

Like others in its species, the Asian giant hornet is unlikely to attack humans—that is, unless its nest or food is disturbed or threatened in some way. If provoked, it will sting, sometimes repeatedly. Its sting is nasty, painful, and may result in an allergic reaction for some.

Then again, the same holds true (to varying degrees) for other species of wasps, hornets, and bees. The biggest difference between other species and the Asian giant hornet is the pain and penetration of its sting, thanks to its powerful and lengthy stinger. It can even penetrate the usual clothing worn by beekeepers and pest control professionals.

5. It is, however, a threat to honeybees.

This insect pest is most often found in rural areas of Japan (thus their other nickname, the Japanese giant hornet), where they feed on other insects, including the Japanese honeybee. As a species, Japanese honeybees have a unique way of fending off Asian giant hornets. Through the beating of their wings, they can literally raise the ambient temperature to a level that the Asian giant hornet cannot withstand.

The same, however, cannot be said of the European honeybees found throughout North America. This is why the Asian giant hornet could become a problem if it were to become established here. The honeybees found in North America, which we need for pollination and honey production, are essentially defenseless against this species, which can easily decimate a honeybee hive. (That's where the "murder hornet" nickname comes from.)

August to October is peak season for Asian giant hornets' honeybee feeding frenzy. Researchers have not yet been able to determine why they favor honeybees over other insects in the fall.

6. If you think you've seen an Asian giant hornet, you're probably mistaken.

In spite of its extremely large size, the Asian giant hornet has a few much more common lookalikes. That means some people may think they've seen one when, actually, they've spotted one of these insects instead:

European hornet (Vespa crabro)

This is the only hornet that is officially established in the U.S.

  • Similar to the Asian giant hornet in size, shape, and color
  • Different in its eye position and abdominal color and pattern

Eastern cicada killers (Sphecius speciousus)

Because they help control the annual cicada population, many consider these native wasps to be beneficial.

  • Similar to the Asian giant hornet in size
  • Different in coloring (especially around the head), with a black-tipped belly

Bald-faced hornets (Dolichovespula maculate)

These native wasps feed on plant-eating insects, such as flies and caterpillars.

  • Similar in very few ways to the Asian giant hornet, other than being aggressive when disturbed
  • Different in that they are black-and-white striped, are much smaller, and create aerial nests

7. The experts are dealing with them.

Fortunately, Asian beekeepers are developing strategies to fend off this honeybee nemesis. For now, in the U.S., there's no real danger to honeybee or human. However, the Washington State Department of Agriculture (WSDA) is preparing to set traps and monitor for this species. Knowing more about the habits and habitats of this (or any other) potentially invasive species, is a preventive measure that will help experts learn how to control them if, it becomes necessary.

8. If you do see an Asian giant hornet, leave it alone.

Why chance a nasty sting? Instead, report the sighting to your local cooperative extension agency or the USDA (and send the carcass if you've spotted a dead one). Really, the best thing you can do is keep calm, stay informed, and let scientists monitor this insect pest.

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