You’ve heard about them on the news, your friends have posted seventy-three memes about them already, but what exactly are murder hornets? These two to three-inch-long invasive species from Japan are not as deadly to humans as the media makes them out to be. But that does not mean we should not worry about them. What is troublesome about the giant Asian hornet (Vespa mandarinia) is their destruction of honeybees. Without bees, the entire human race is put in jeopardy. Let’s learn about “murder hornets.” What are they? How you can be more informed than your neighbor who thinks of them as something out of a horror movie, ready to kill every human they come into contact with. 

Murder hornet

Biology of the Giant Asian Hornet

Giant Asian Hornets are the record holders for size. They are the largest hornet of all species with queens measuring two and a half to three inches in length, while workers measure about two to two and a half inches. They are distinctly colored with bright orange heads and orange striped abdomens. Giant Asian Hornets have a stinger that measures nearly one centimeter in length, much longer than most other hornets. The wingspan of these hornets can be up to three inches in diameter, depending on the size of the specimen. The head of these giant hornets is also fuller than most other hornets, giving them an animated appearance when seen head-on. The extended facial features house large muscles that power enlarged mandibles that are used to rip the heads off their prey. The favored form of predation of the Giant Asian Hornet is called slaughter, which is how they got their nickname of “murder hornet.” When they find a food source, such as a colony of honeybees, they will eliminate nearly the entire population in only a matter of a few hours. 

Giant Asian Hornets have been known to decimate entire colonies of honeybees. However, this is not their only food source. Hornets of all varieties are carnivores preying on several insects, including large beetles, other hornets, wasps, and honeybees. The venom of the Giant Asian Hornet can kill mice and other small animals. Because of their enlarged size, they deliver roughly seven times more venom than most other bee species, making their sting one of the most painful. Because hornets do not lose their stinger after the attack, they can deliver multiple stings. While this is cause for concern to those with bee allergies, most of the population can survive even multiple stings by a Giant Asian Hornet, though it will be quite painful. 

How Did Invasive Giant Hornets Get Into the US?

At this time, it is unknown exactly how the Giant Asian Hornets made their way to the US. The experts at Texas A&M University in College Station, TX, theorize that it is likely a queen found a wintering spot inside a container ship bound for the Pacific Northwest. This hibernation in a container would have lead to her accidental transport across the ocean. Currently, Giant Asian Hornets have only been spotted in Southwestern Canada and the Pacific Northwest in Washington State. 

There is no giant population of killer bees waiting to spread out across the United States. Still, because of their destruction of honeybee populations, we must eliminate any potential colonies before they begin to multiply. As with many invasive species, competition with native species becomes an issue. If the environment cannot support the invasive species, the ripple effect on native species can be disastrous. 

Additionally, honeybees are crucial pollinators. They are responsible for nearly eighty percent of the pollination of cultivated crops. Without bees, food crops would be significantly depleted, leading to mass shortages in the worldwide food supply. Giant Asian Hornets are predators of the honeybee, and due to their slaughter hunting, this can be a concern for beekeepers. Currently, these hornets have only been identified in the Pacific Northwest of the United States. A live colony was found and eliminated in the Southwestern province of British Columbia in Canada. To date, there is not much to worry about throughout the rest of the US, unless more live colonies of Giant Asian Hornets are located in this or other regions. 

Why You Should Be Worried About Bee-Killing Hornets

The cause for concern with Asian Hornets is that they can decimate an entire bee colony in a matter of hours. These giant hornets will hang outside a honeybee nest and attack workers as they come and go. Within hours the entire colony will be eradicated. This slaughter is how the Giant Asian Hornet came to get its name, “murder hornet.” These hornets rip the heads off their prey and feed the thorax to their young. Beekeepers are the only ones that need to worry about potential populations of the Giant Asian Hornet. However, aside from beekeepers, most people find these and all hornets to be useful, as they eat a multitude of crop-destroying bugs, including caterpillars. Honeybees are not the only prey on the list of the Giant Asian Hornet. So long as populations do not grow, the “murder hornet” isn’t much of a threat right now in the US. However, the State Department of Agriculture in Washington State has set up a report line so that if you see one of these Giant Asian Hornets, you can report its sighting and help to reduce the spread of this invasive species. 

Do Murder Hornets Really Kill Humans?

Giant Asian Hornets are worrisome if you meet one because they have longer stingers than most hornets. Beekeepers need to be careful because these extra-long stingers can also pierce typical beekeeping protective gear. The venom of the Giant Asian Hornet isn’t any more potent than a honeybee’s sting; however, because of their size, they deliver about seven times the amount of venom. Unlike honeybees, the Giant Asian Hornet doesn’t lose its stinger after stinging its prey so that it can sting multiple times. This additional delivery of venom is what can prove to be hazardous for humans. In Japan, Giant Asian Hornets cause between thirty and fifty deaths per year. But those deaths are attributed to allergic reactions and anaphylactic shock, rather than toxicity from the venom itself. This makes the “murder hornet” no more dangerous than any other bee for most humans. Still, caution should be observed by those with bee allergies. 

Next Steps to Prevent the Spread of the Murder Hornet

The good news is that Giant Asian Hornets do have a natural enemy, which is plentiful in the US, the praying mantis. But here’s the truth, only two dead Giant Asian Hornets were found in Washington State in late 2019, and one live colony in Southwestern Canada was found and eliminated in 2020. The media hype about Asian Hornets is just that…hype. Here in the US, we really don’t have to worry much about this species unless more colonies start being reported. 

If you happen to be traveling in the Pacific Northwest and find yourself near a giant hornet, the Washington State Department of Agriculture has a website where you can upload a photo and report your sighting. Most, if not all, of the images submitted at this time, are not “murder hornets” but rather a close cousin of Vespa Mandarinia, the Giant Hornet Vespa Velutina. Concerned parties can snap a picture of the offending hornet and upload it to: http://www.maps.arcgis.com/apps/GeoForm/index.html?appid=e3720c303c414210967920b07bad13f5

You will be asked to answer a few simple questions, such as where you were when you took the picture as well as some information about yourself. 

Do I need to worry about the Giant Asian Hornet?

At this time, only two dead hornets have been reported in Washington State. However, there has been evidence of further colonies. Local experts have been setting out traps in the hopes of slowing down the possible spread of the hornet. These giant hornets, while large, are not “killer bees.” At least not to humans. The venom, while not any more toxic than honeybees, is delivered in a larger dose, making the sting and post-sting pain and swelling a lot worse than a honeybee’s. The only real concern at this time is the threat they pose to honeybee populations as their numbers have been declining for the last several years. Honeybees are responsible for pollinating about eighty percent of the world’s food crops, so without them, man then becomes in jeopardy of declining crop production and world food supply. 

Resources:

UF | IFAS
http://entnemdept.ufl.edu/creatures/MISC/BEES/Vespa_mandarinia.html

National Geographic:
https://www.nationalgeographic.com/animals/2020/05/why-asian-giant-hornets-have-painful-stings/

NY Post:
https://nypost.com/2020/05/07/grisly-video-shows-praying-mantis-eating-brain-of-a-murder-hornet/

NCSU | Entomology:
https://entomology.ces.ncsu.edu/2020/05/asian-giant-hornets/

Washington State Department of Agriculture:
https://agr.wa.gov/departments/insects-pests-and-weeds/insects/hornets
https://www.maps.arcgis.com/apps/GeoForm/index.html?appid=e3720c303c414210967920b07bad13f5

Washington State University:
https://news.wsu.edu/2020/04/06/wsu-scientists-enlist-citizens-hunt-giant-bee-killing-hornet/

Entomology Today:
https://entomologytoday.org/2020/05/11/big-beautiful-confusing-deciphering-true-hornets-vespa/

Texas A&M:
https://entomology.tamu.edu/2020/05/11/get-to-know-the-asian-giant-hornet-or-murder-hornet/
https://today.tamu.edu/2020/05/13/get-to-know-the-asian-giant-hornet/

Virginia Tech, Department of Entomolgy
https://www.ento.vt.edu/News/Asian_Giant_Hornet.html

Dusty Showers has been in the urban nuisance wildlife and pest control field since 1993. Taught by Garon Fyffe, a pioneer in humane nuisance wildlife management, Dusty has a passion for finding humane solutions to human & wildlife conflicts. Dusty was the only individual invited by the Florida Fish & Wildlife Commission in the lat 1990's to help write legislation for legal protection of Florida bats. With an instinct for solving wildlife, Dusty found pest control to be an easy "add-on interest". Dusty started his first business "Animal Instincts Wildlife & Pest Management" in the Tampa Bay, Florida area in 1995. Eventually selling Animal Instincts in 2002, Dusty went on to start Creepy Creatures Termite and Pest Control in 2009, which he still owns and operates today in Palm Harbor, Florida.