"Murder hornets" in America: What you need to know

The Asian giant hornet, popularly known as the "murder hornet," has been a source of increasing worry in the United States since they were first spotted here in late 2019. The invasive hornet — the world's largest — can decimate entire hives of honeybees, which are necessary to pollinate many crops. The hornets can lay waste to tens of thousands of bees within just a few hours.

They also can deliver painful stings to humans. Their venom is so potent, it can dissolve human flesh and can kill a mouse in a few seconds.

In August 2021, state authorities in Washington and Oregon found the first Asian giant hornet nest of the year and made plans to eradicate it. Here's everything you need to know about the worrisome creatures, and up-close photos of the hornets in action. 

A new nest?

Here's a photo of the first live sighting of an Asian giant hornet in the United States in 2021. It was reported by a resident of Whatcom County, Washington, in August.

WSDA workers netted, tagged and released three hornets between August 11-17. One hornet slipped out of the tracking device, another hornet was never located, and one eventually led the team to the nest.

Yep, a new nest

WDSA experts found the nest in a rural area east of Blaine, Washington, about a quarter of a mile from where the insect was sighted.

Inside a murder hornet nest

In October 2020, a nest was spotted and eradicated in Washington state. The Washington State Department of Agriculture later brought the nest to a research center, where it was split open and examined. Two hornet queens were captured alive.

This was the first known murder hornet nest to be found and eradicated in the United States. Researchers for the WSDA shared these photos in late October 2020 after cutting open the nest in a state facility. 

Queens, captured

Two live queens were found in the nest. Here they are, as seen in a video shared by WSDA researchers. It wasn't immediately clear whether the queens had reproduced.

Wider view of nest

This picture, shared by WSDA researchers as they opened the nest for the first time, can give you a sense of scale. 

The log where the nest was nestled was kept in a walk-in cooler until researchers were ready to examine it.

"New queens emerging"

"At least between the time we conducted the eradication last Saturday and now, there were new queens emerging within the nest," WSDA spokesperson Karla Salp said on Nov. 1, 2020. "There may have also been queens that emerged before we got there. We just don't know at this point." 

Proto-killers

During their examination of the nest, the team found several larvae in the comb and white-capped cells with developing adults. 

A troublesome bug

How did researchers find the full nest? It wasn't easy; it involved tiny pieces of technology, and some sugary strawberry jam to keep the hornets distracted once they were tracked.

Nest spotted

Washington State Department of Agriculture entomologists found the Asian giant hornet nest in Blaine, Washington, on October 23, 2020 — the first one ever found in the U.S. 

The property owner gave the agency permission to eradicate the nest.

Doomed nest

The nest was carefully destroyed by agriculture department workers and brought back to a research facility.

In search of giants

To locate the nest, a WSDA trapper collected two live Asian giant hornets that were caught in a new type of trap. The following day, officials found two more live hornets in another trap in the same area. 

How they did it

Entomologists attached radio trackers to three hornets. They were then released in an area that has been reporting murder hornet sightings for months. 

After they cut into the nest, the researchers found the radio tag that led them to it; it appeared to have been chewed off. 

Tracked to the source

One of those hornets led bug-hunters to the discovery of a nest inside the cavity of a tree. Asian giant hornets normally nest in the ground, but they sometimes nest in dead trees. 

Dozens of the hornets were seen buzzing around the tree when the WSDA team arrived.

Here's the nest

Here's a screen grab from a WSDA video documenting the nest.

Delicate work

Here's a close-up of an entomologist at work on an Asian hornet.

More traps

There is a network of Asian hornet traps, some set by WSDA staff and hundreds more placed by citizen scientists and other cooperators throughout the state. 

What is it eating?

Experts used grape juice — among other lures, apparently — to attract the hornets. Once captured, they enjoyed some strawberry jam.

No more nest

On October 24, 2020, experts descended on the nest and destroyed it.

The team stuffed dense foam padding into a crevice above and below the nest entrance. Next step: wrapping the tree with cellophane, leaving just a single opening. Then the team inserted a vacuum hose to suck the hornets from the nest.

Vacuum full of hornets

In all, the entomologists removed 98 worker hornets. During the early-morning extraction, 85 hornets were vacuumed out of the nest.

Suited up

The whole team had to wear protective suits, of course. The WSDA suspects there may be other nests in the area as well.

Murder hornets on the loose

News of the nest followed a frustrating setback for the state of Washington. In October 2020, scientists from the WSDA affixed tracking devices to two of the invasive species and set them loose. The plan: Follow the buzzing bug back to a nest and destroy it. But things didn't go exactly as the humans had hoped.

What big mandibles you have

The Asian giant hornet can grow up to two inches long. It uses its sizable mandibles to snip the heads off of smaller insects, notably honeybees, for food. Within the mandible, these insects also have a black tooth that they use to dig underground nests.

Wondering what it looks like when these hornets are hungry? Check out the next photo.

How the murder hornet earned its name

This photo from Nagano, Japan, shows two Asian giant hornets hunting. 

And a big stinger too

The hornet's stinger alone is one-quarter inch long, long enough to penetrate regular beekeeping suits.

A royal wingspan

Scientifically, they're known as the Vespa mandarinia. The queens (top row) are the largest of the species, growing to 2 inches long with a 3-inch wingspan. For reference, that's wider than an iPhone X. Worker hornets grow to be 1.4 to 1.6 inches long.

Now, here's what happened with the two live-captured hornets in Washington and what it all means.

Live and murderous

In August 2020, the first live murder hornet specimen turned up in a bottle trap near near Custer, Washington in Whatcom County. Researchers hoped to use the specimen to research and combat the species.

A new use for dental floss

Here, a researcher uses dental floss to attach a tracking device to the hornet's abdomen.

High hopes, big stakes

Scientists and farmers alike were hoping to follow the two captured live hornets back to their nests before the insect's mating season, in the fall.

Farmers in the area are concerned that a large-scale slaughter of the honeybee population could be detrimental to next year's berry crop.

Make sure the knot is tight

The first time scientists tried to track a live hornet back to the nest, they attached the tracker with glue. But the glue did not have adequate time to dry before the hornet was released and came loose almost immediately. The first hornet was gone, quite literally, without a trace.

Taking flight

The WSDA hoped the second attempt would be more fruitful than the first.

Get back here

Here are two scientists attempting to track the hornet back to the nest. The problems began when the hornet flew into some blackberry bushes. The tracker signal was lost in the vegetation. 

The scientists were unable to pick up the signal again. 

First confirmed sighting

This murder hornet madness first began in December 2019. Washington state officials verified two reports of the dangerous insect near Blaine, just south of the border with Canada — the first such sighting in the U.S.

Since then, pest control and government agencies have received unconfirmed reports of sightings as far south as Portland, Oregon. Experts say these hornets are not generally a threat to humans, but could pose a danger to the already struggling U.S. bee population.

"Murder" in the Pacific Northwest

In July, 2020 — more than seven months after the first sighting in the state — the Washington State Department of Agriculture trapped the first of these oversized insects. The dead specimen was collected near Birch Bay in Whatcom County, just a few minutes drive south of the original sighting location outside of Blaine.

Next step: Eradication

The WSDA still plans to use infrared cameras to locate nests.

Asian giant hornet mating season takes place in the fall.

The life cycle begins

The murder hornet's life cycle has several phases, beginning around April. Queens spend the spring building up their colonies in underground nests. A finished nest is about the size of small human child.

A new queen

During the spring and early summer months, worker hornets — female hornets that do not reproduce — help new queens, like the one seen here, to maintain the hive and raise the larvae. 

Meanwhile, adult male hornets hunt alone and bring their plundered insect proteins back to the nest to feed their young.

The slaughter phase

In the warmer summer months, swarms of Asian giant hornets ambush beehives in groups; this behavior is literally called the "slaughter phase."

The bees never had a chance

Here's another angle of murder hornets swarming a beehive, ambushing the bees inside.

Occupying a beehive

Finally, once the hornets' insectile coup is complete, they begin the "occupation phase." Hornets stick around in an overthrown beehive for several days, even up to two weeks, feasting on the young bees inside.

Here, two Asian giant hornets enjoy the spoils of an occupied hive.

Hornet reproduction

Mating season for the Asian giant hornet takes place in the fall. Queens release pheromones to initiate reproductive behavior from male hornets. After fertilization, queens leave the nest to start their own colonies.

As with many hornet species, fertilized eggs hatch into female hornets — the next generation's queens and workers. Unfertilized eggs, with just one chromosome set, become male hornets, called drones.

But do they really pose a threat to humans?

Fortunately, scientists say that the Asian giant hornet is generally not aggressive to people unless their nests — or occupied hives — are disturbed.

Hypothetically speaking, how dangerous are they?

The murder hornet has been known to kill up to 50 people each year in Japan. Sting survivors describe the venom, packed with powerful neurotoxins, as excruciating.

And, as we mentioned before, regular beekeeping suits can't protect you from the long stinger of the Asian giant hornet either. YouTube personality Coyote Peterson once showed what the sting was like on his wilderness series.

This is the murder hornet suit

No, this is no average beekeeping suit. 

Here, entomologist Chris Looney shows off the extra-thick protective gear he'll wear when investigating a possible Asian giant hornets nest. 

But how did they get here?

Karla Salp, a spokesperson for the Washington Department of Agriculture, says that, though it's unclear how the Asian giant hornet wound up on the North American continent, insects can sometimes become "unwitting hitchhikers" on a shipping container or traveler.

In this photo, Looney poses with a dead murder hornet on his jacket.

Entomology crosses the Pacific

Scientists in Japan have been helping entomologists here in North America run genetic tests on the huge insects. The hornets have also been found in British Columbia, Canada. 

Here, Sven Spichiger, an entomologist with the Washington State Department of Agriculture, poses for a photo with an Asian giant hornet sent from Japan.

A tasty snack?

In Japan's central Chubu region, the Asian giant hornet is not just considered a pest. It's also a delicacy. 

Adult hornets are fried on skewers and eaten whole — stinger and all. It is said that eating these insects produces a pleasant tingling sensation in the mouth. Live hornets are also drowned in shochu, a Japanese liquor. Before they die, the hornets release their venom into the spirits.

Trapping the invasive hornets

The Washington State Department of Agriculture hopes to limit the spread of the Asian giant hornet through trapping. Entomologist Chris Looney places a trap in a tree near Blaine, Washington.

Trap the hornets yourself

The Washington State Department of Agriculture has a detailed set of instructions for residents who wish to build and maintain hornet traps.

The WSDA warns volunteers that placing hornet traps may increase their risk of being stung.

Hanging a hornet trap

The traps are made from plastic bottles with a hornet-sized hole cut into one side. The liquid bait in the trap is a mixture of rice cooking wine and orange juice. The bottles should be hung from sturdy branches near the edges of a forest, according to the WSDA.

Residents can report the locations of any traps online.

Checking your traps

Traps should be inspected and the bait replaced each week for 17 weeks, per WSDA recommendations.

Collecting the specimens

Residents who successfully trap any insects — not just Asian giant hornets — should collect the solid contents from the bottle, draining the liquid with a mesh strainer, and transferring the specimens into a plastic food-storage container.

What other kinds of insects appear in the traps?

Entomologists in Washington collected this bald-faced hornet (top) in one of their traps. As you can see, bald-faced hornets are much smaller than the Asian giant hornet.

The adult bald-faced hornet only grows to be about 0.75 inches long, on average, less than half the size of a queen murder hornet.

Hanging a refilled trap

After specimens are removed and the bait refreshed, traps should return to their branches.

Hornets by mail

Any specimens collected in the traps should be wrapped in a paper towel soaked in isopropyl alcohol, deposited in a zip-closure bag and mailed to the WSDA with the trap number and collection date.

You can find the full instructions on the WSDA website.

But did I see a murder hornet in my neighborhood?

None of the insects pictured here is an Asian giant hornet. Many striped insects are commonly found across the United States. Some are even very large.

Unless you live in the Pacific Northwest, it is extremely unlikely that you have spotted a murder hornet near your home, according to experts.

Keep going for a handy cheat sheet to help you identify these common insects buzzing or crawling around your neighborhood.

Cicada killer wasp

This is not an Asian giant hornet. It is a cicada killer wasp. 

These solitary digger wasps can grow up to 2 inches in length and prey on cicadas. They are common in the eastern and midwestern U.S. They are not aggressive and rarely sting humans.

Paper wasp

Paper wasps can also have yellow and black stripes, but they only grow from one-half inch to 1.5 inches long. They are found in every region of the U.S. and are rarely aggressive, unless their hive is directly disturbed.

Yellow jacket wasp

These wasps are found across the United States and are known for their aggression. They will pursue any perceived threat and sting repeatedly and painfully. If you're being chased by a black and yellow bug, it may be a yellow jacket that's the culprit.

Bald-faced hornet

Technically speaking, "bald-faced hornet" is a misnomer. This insect is actually a black-and-white variation of the yellow jacket wasp, and their aggressive behavior reflects that.

As you saw before, this wasp only grows to be around half the size of an Asian giant hornet. The species is native to the North American continent and can be found in most U.S. states.

Mud dauber wasp

The mud dauber, also found throughout the United States, builds its nest from mud. They are easily identified by their defined hourglass shape. Mud daubers feed on spiders and rarely sting people. Blue mud daubers are a primary predator for the black widow spider.

Honey bee

The honey bee is an important pollinator for many varieties of plants. The murder hornet preys on honey bees.

Jerusalem cricket

Found in the western United States, the Jerusalem cricket is not actually a cricket at all. It is a large, flightless, nocturnal insect with bold stripes and large mandibles. It can produce a painful bite if stepped on.

Need more help identifying these hornets?

The Washington State Department of Agriculture has provided these photos to the public...

Telltale characteristics

Here, it's easy to see the differences between a honeybee, a yellow jacket, and the Asian giant hornet.

All we know

More public information on Asian giant hornets can be found via the state of Washington.