In late 2019, two unusual hornets with orange and black markings and long stingers were spotted in Washington State. This is the first time these species invaded North America. Further investigation by the Washington State Department of Agriculture and a managing entomologist revealed they were murder hornets, the world's largest wasps, growing nearly two inches in length.
So what are murdering hornets? Also referred to as Asian giant hornet (Vespa mandarinia) as it’s native to Japan and well established throughout East Asia, including Laos, Thailand, Cambodia, Myanmar, Vietnam, and Sri Lanka, this invasive species targets a honeybee, which pollinates crops. They can get rid of a bee colony and a bee nest in just a few hours, and they can also spit venom and inflict numerous powerful hornets' stings on humans.
More commonly five times bigger than a honeybee, murder hornets have a big, firm yellow or orange head with black-colored, teardrop-shaped eyes. The mid-part (the thorax) is dark, and in adults, it tapers in at the waist to intersect the bottom section, known as the abdomen.
Some other bugs look almost the same, but most are evidently smaller than the murder hornet. You can identify larger lookalikes like the western cicada killer wasp and the eastern cicada killer wasp by their smaller heads, lighter-colored thoraxes, and rounder eyes. The bands on their abdomens also appear distinct.
The most common type of hornet in the United States, the bald faced hornet, on one hand, greatly differs in appearance as it’s largely black in color, with a mostly white face. The European hornet sports a brown with yellow abdominal stripes and a pale face.
Queens of this giant hornet, regarded as “the world’s largest hornet,” can grow some 5 centimeters (2 inches) long, about the length of an average-sized woman's thumb. Wingspans can exceed 7 centimeters (2.8 inches), which isn’t quite the entire width of a woman's palm. Workers, on the other hand, have a smaller size.
The Asian giant hornet, the world's largest hornet, isn’t to be confused with the Asian hornet (Vespa velutina), a wasp species also native to many Asian countries, that's been found in Europe since 2004. The species has distinctive yellow legs and its thorax is a velvety brown or black with a brown abdomen.
Murder hornets are less direct threats to humans, although they’re a major problem to the honeybee population. The bee population is beneficial to humans as they’re reliable pollinators. In fact, bees are responsible for pollinating nearly 85 percent of all food crops for humans. These native species mostly target wild bees and honeybee hives during late summer and early fall. They attack the honeybee colony when worker hornets need to provide food for developing young. They strike the entire hive, kill the adult bees, leave their bodies at the bottom of the hive, and bring developing bees, in the form of larvae and pupae, back to their nests for food.
Learn More: Hornets vs Bees
Murder hornets aren’t typically dangerous to humans, but they’ll sting to defend their nest or to keep you distant from a honeybee hive they’ve invaded. If that occurs, their larger size can make their stings worse than those from other insects. There are several reasons for this. First is because their stinger is longer than that of other wasps, and second because their sting can cause a lot more venom and can damage tissue.
Like other wasps and hornets, murder hornets can sting several times. Though it’s very rare for a group of hornets to attack a human, it’s still possible and can be serious if it does occur.
A beekeeper's clothing often can’t defend against the murder hornets’ stings. The murder hornet's stinger is long enough to pass through protective garments. Individuals who are allergic to bee stings or wasp stings should be especially careful around murder hornets.
To give you an idea, a murder hornet transmits a substantial dose of a fairly strong venom. Its sting can deliver a lot of venoms, generally up to 1,100 micrograms (dry weight). That’s more than seven times as much as a little honey bee delivers. The murder hornet venom's knockdown power is to be reckoned with. Seeing what its venom did to laboratory animals, experts say that just one full sting would have a fifty percent likelihood of killing a decent-sized rodent. It’s estimated that the murder hornet’s sting is equivalent to three to 10 yellow jackets stinging at once.
While only a few sightings in the Pacific Northwest of the United States and British Columbia’s Vancouver Island have been confirmed, it’s still best to avoid murder hornets and murder hornet nests. Always move away calmly from it. Swatting at it is not a good idea as it might sting you. If a hornet or hornets get into your vehicle, stop and calmly open all the windows and get out of the car if you’re in a safe enough place.
Furthermore, properly keeping these invasive insects from setting up camp around your home starts with establishing pest control prevention, so plan ahead. Before spring begins, make sure to inspect your house, yard, and any surrounding structures for places that can serve as hornets’ nest.
To make you less prone to attract them in the first place:
There are many things you should do after a hornet sting. Let’s hope that everything will go away after hours of pain and a rash.
Learn More: How to Treat a Hornet Sting
Murder hornet isn’t a species you would want to tolerate anywhere near your home. Suppose you have seen murder hornets' nests (typically underground, such as in abandoned burrows or cavities around tree roots), it’s best to stray away from them as the murder hornets will attack as a group, attracting other members of the colony to join the stinging party. The amount of venom they can inject through several stings can make them hazardous to kids as well as individuals with existing health problems.
It’s best to report it to your state or province's agriculture department immediately or contact an entomologist or pest control specialist to confirm if what you’ve seen are indeed murder hornets’ nests.
The first step to be taken in hornet control is to know the wasp species. At Positive Pest Management, we can help determine and exterminate these stinging insects away from your property through our complete pest control services.
Contact us today for a free estimate.