Mysterious Bald Eagle Killer Finally Identified

Illustration for article titled Mysterious Bald Eagle Killer Finally Identified

Photo: Doug Pensinger (Getty Images)

In a new study out Thursday, scientists say they’ve solved the mystery of a neurological disease that’s been killing bald eagles and other birds in the U.S. for over 25 years. The disease appears to be caused by a toxin produced by a species of blue-green algae that grows on an invasive plant—a toxin that may be churned out in the presence of certain pollution.

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In 1994, there was a mass die-off of bald eagles in Arkansas. Before death came, the predatory birds would lose their navigation skills, crashing into trees or even losing their ability to fly. And when scientists examined their brains post-mortem, they found distinct lesions and holes inside, making it look like the brain had been eaten away. Eventually, it was determined that the eagles had caught the illness from the waterbirds they preyed on that often displayed similar symptoms before death. The condition came to be known as avian vacuolar myelinopathy (AVM).

Though scientists suspected AVM was infectious in some way, the exact culprit remained unknown for years. Along the way, more outbreaks of AVM occurred throughout the Southeastern U.S. near lakes and other fresh sources of water. By the early 2000s, a clear connection had been made between the spread of an invasive aquatic plant called Hydrilla verticillata and AVM. By 2015, researchers at the University of Georgia provided evidence that a specific species of cyanobacteria—bacteria that photosynthesize—that grows on this plant was responsible for AVM. The group named the previously undiscovered species Aetokthonos hydrillicola, translated from Greek and Latin to “eagle killer, living on hydrilla.”

Bacterial colonies of the cyanobacterium Aetokthonos hydrillicola growing on a leaf of the invasive aquatic plant Hydrilla verticillata.

Bacterial colonies of the cyanobacterium Aetokthonos hydrillicola growing on a leaf of the invasive aquatic plant Hydrilla verticillata.

Cyanobacteria are also called blue-green algae for the color they give off when they group together in massive numbers (despite the nickname, they’re not true algae, a vague term given to many species of aquatic plants). They’re often dangerous to animals, including people, because of the toxins they can produce. But when scientists at the University of Georgia and elsewhere tried to study A. hydrillicola in isolation, they came across a problem: The bacteria they grew in their lab were harmless to birds. They seemed only to be dangerous when growing on the plant.

In this new study, published Thursday in the journal Science, scientists at the University of Georgia worked together with researchers from Germany and the Czech Republic to unravel the final pieces of the AVM puzzle. Their work indicates that A. hydrillicola only produces the toxin that causes AVM when it’s also around bromide, the negatively charged version of the element bromine.

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Once they discovered this connection, the researchers were finally able to induce this toxin from their lab-grown samples of A. hydrillicola and found that it could kill birds in the same way AVM does in the wild. Genetic analysis of the bacteria also uncovered the specific bits of DNA that allow it to make the toxin. They dubbed their new discovery aetokthonotoxin (AETX), translated to “poison that kills the eagle.”

“We confirmed that AETX is the causative agent of [vacuolar myelinopathy],” the researchers wrote in a summary of their findings.

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While the exact method of killing behind AVM might be solved, there are still lingering questions. Namely, where exactly is the bromide that fuels the production of this toxin coming from, and why does AVM seem to be localized only to the U.S.? Bromide exists naturally in lots of places, but it’s also seen in many synthetic chemicals that could find their way into the aquatic environment. In particular, it can be found in certain herbicides used to control the spread of the Hydrilla plant around water treatment facilities and elsewhere. So it’s possible that, in trying to get rid of one problem, we helped create a separate environmental crisis.

More research will have to be done to confirm the role of these herbicides and other human-created sources of bromide in causing AVM outbreaks, but the authors already recommend that they shouldn’t be used to control Hydrilla populations any longer. Because this toxin can accumulate in other animals besides birds, such as reptiles, fish, and amphibians, it’s also possible that it can sicken mammals, including humans.

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Toxic blooms caused by algae (including blue-green algae) have already become more intense worldwide over the past few decades, and warming temperatures will likely only worsen the situation. And while AVM outbreaks have only been seen in four states to date, the scale of the problem is probably larger than what’s been officially documented.

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Revealing the identity of this eagle killer is definitely cause for celebration, but stopping it will be a whole new challenge.

Florida Bans Sale of Invasive Reptiles as Iguanas and Snakes Take Over

A 14-foot, 95-pound, female Burmese python captured in Naples, Florida.

A 14-foot, 95-pound, female Burmese python captured in Naples, Florida.
Image: Robert F. Bukaty (AP)

The Florida Fish and Wildlife Conservation Commission is clamping down on invasive reptiles, making it illegal for Floridians to breed or sell these problematic creatures except in special circumstances.

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In an effort to protect local ecology, economy, and human health, the state is making it illegal for Floridians to breed or sell such animals as Burmese and scrub pythons, Green anacondas, Nile monitors, green iguanas, and tegus, among several other invasive species. Finalized on February 25, the new rules are meant to improve the regulations on the ownership of invasive reptiles in Florida, and they’re expected to go into effect later this summer.

“Stringent biosecurity measures are required for those entities in possession of Prohibited species to limit escapes,” declares the Florida wildlife commission in its guidelines.

These reptiles are becoming a major menace in the state, ravaging sensitive ecosystems and wreaking havoc in urban environments. The Burmese python, for example, is now endemic in the Everglades, where it consumes a wide variety of prey. Green iguanas have been plaguing home and business owners for years, digging up gardens, damaging sidewalks and seawalls, and occasionally popping up in toilets (yes, seriously). Green iguanas also carry salmonella. So bad is this problem, that the wildlife commission has urged homeowners to kill green iguanas “whenever possible” and without the need for permits.

As the new guidelines stipulate, pet owners will have 90 days to comply with the rules once they go into effect. Except in situations involving requirements to improve outdoor enclosures, which give owners 180 days to comply.

Possession of these animals may be permitted under special circumstances, such as for educational purposes or for “eradication/control activities,” which the Florida wildlife commission describes as a “targeted, systematic effort to remove an entire population of a nonnative species or to contain or otherwise manage the population of an invasive species so as to minimize its spread and impacts.”

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Green iguanas and tegus are still being permitted for personal use (i.e. pets), but those cases will require special permits. These animals can be owned for the duration of their lives, but the commission will only include animals that were owned prior to the new rules going into effect. Owners will have to make sure these animals are marked with a Passive Integrated Transponder (PIT) tag, and they’ll have to renew their permits annually.

Some pet owners in Florida won’t be happy with the new guidelines, and some breeders will likely have to revise their business plans. Sucks, but the environment is important, as is property, not to mention human health and safety.

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Snakes Invented an Incredibly Creepy Way to Climb Trees

Video showing the “lasso” mode of locomotion at 10 times normal speed (the gif is sped up from the original video, which showed 5x normal speed).
Gif: Thomas Seibert/Gizmodo

Jaw-dropping footage taken in Guam shows a previously unknown climbing strategy employed by brown tree snakes.

New research published in Current Biology describes a fifth mode of locomotion in snakes, the other four being sidewinding, rectilinear, lateral undulation, and concertina. The newly discovered form of climbing, dubbed “lasso locomotion,” could result in better mitigation strategies to protect the native bird population from the invasive brown tree snake (Boiga irregularis). The snakes were inadvertently introduced to the island in the 1940s and 1950s, after which time the native bird population began to plummet.

In fact, this lasso locomotion—in which the snakes create a loop with their bodies to generate friction—may be contributing to the “success and impact of this highly invasive species,” allowing them to exploit resources that “might otherwise be unobtainable,” wrote the authors, led by ecologist Julie Savidge from Colorado State University, in their new paper. The lasso technique likely evolved to help them climb trees, but the snakes are now using the method to climb artificial structures like utility poles.

That these nocturnal snakes are slithering amok on Guam is a serious problem. Most of the native birds on the island have disappeared since the snakes’ arrival, with Micronesian starlings and a species of cave-nesting birds being the last to survive. The starlings are of particular ecological importance, as they distribute fruits and seeds across the island. What’s more, these snakes, being proficient climbers, also cause damage to human infrastructure, and they’re responsible for frequent power outages on the island. Thus, it’s important that scientists figure out what brown tree snakes can and cannot climb.

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Savidge, along with CSU ecologist Thomas Seibert, was studying the nesting habits of Micronesian starlings when they stumbled upon the finding. To protect the birds, a nest box was placed atop a tall pole.

“And although we knew the starlings could successfully nest in our nest boxes on larger round utility poles, utility poles are limited in distribution and we wanted to know if we could protect birds nesting in bird boxes on top of EMT poles that had stovepipe baffles attached below the nest box,” explained Savidge in an email. “Stovepipe baffles have been used to keep other snakes and raccoons away from nest boxes on poles in the yards of bird-watchers.”

The scientists were testing the ability of snakes to climb this baffle when the new form of locomotion was discovered.

A brown tree snake on a pole.

A brown tree snake on a pole.
Image: Bruce Jayne

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“We didn’t expect that the brown tree snake would be able to find a way around the baffle,” said Seibert in a CSU press release. “Initially, the baffle did work, for the most part. Martin Kastner, a CSU biologist, and I had watched about four hours of video and then all of a sudden, we saw this snake form what looked like a lasso around the cylinder and wiggle its body up. We watched that part of the video about 15 times. It was a shocker. Nothing I’d ever seen compares to it.”

In total, the scientists observed five different snakes performing the maneuver, climbing up smooth cylinders between 5.9 to 7.9 inches (15-20 cm) in width. A typical brown tree snake measures around 54 inches (138 cm) long.

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Intrigued—if not horrified—by the video, the team recruited Bruce Jayne from the University of Cincinnati, an expert on the mechanics of snake locomotion, who helped study and describe the previously unknown form of climbing. On closer inspection, Jayne noticed how the snakes form bends within the loop of the “lasso,” which helps the animal move upwards.

“The loop of the ‘lasso’ squeezes the cylinder to generate friction and prevent slipping,” said Jayne in an email. “The little sideways bends within the loop of the lasso serve two important functions. First, they provide a mechanism for tightening the loop by using the largest groups of muscles within the body of the snake, and second, they move the snake upward bit by bit as they move toward the tail of the snake and around the circumference of the cylinder.”

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Screencap taken from the video abstract.

Screencap taken from the video abstract.
Image: J. Savidge et al., 2021.

Typically, tree-climbing snakes, when using the concertina form of locomotion, bend sideways to latch onto two places at once. This is fundamentally different, however, as the loop of the lasso is used to grip a single spot on the cylinder.

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It’s an impressive feat, but the lasso method requires intense physical effort. The snakes move upwards very slowly, breathe heavily, take frequent breaks, and often slip. The scientists don’t know how common this technique might be in other species or places, but it’s possible other snakes can do this.

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“To date, I am not aware of anything remotely similar to the lasso locomotion of brown tree snakes in other species,” said Jayne. “However, there are more than 3,500 species of snakes with hundreds of species that climb trees, and sometimes animals in nature perform rare behaviors that have never been observed in laboratory conditions. Thus, much remains to be learned about this issue.”

Equipped with this knowledge, the team now plans to build better protective barriers and study this snake in more detail to fully understand how it pulls off this mind-bending trick.

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Honeybees Fend Off Asian Giant Hornets With Poop

Eastern honeybees at the Ginza Honey Bee Project in Tokyo, Japan in 2014.

Eastern honeybees at the Ginza Honey Bee Project in Tokyo, Japan in 2014.
Photo: Chris McGrath (Getty Images)

Attacks by giant hornets, relatives of murder hornets, on honeybee hives are absolutely horrifying. Worker hornets identify bee hives and then bring in reinforcements of two to dozens of others, slaughtering bees at a rate of up to one per 14 seconds and sawing off their heads to gather protein-rich thoraxes and feast on pupae and larvae.

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The hornets are too well armored for direct attacks with stingers, but in the past, scientists have observed Japanese honeybees swarming the attackers and cooking them alive in body heat. New research published in PLOS ONE on Wednesday highlights another defensive strategy that Asian honeybees use fend off giant hornets: animal poop.

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The study began when University of Guelph professor Gard Otis and another member of the research team learned from a Vietnamese beekeeper that surface areas near the entrances to Eastern honeybee (Apis cerana) hives were smeared with buffalo poop. From there, the researchers learned that the bees were actively gathering droppings from local fauna as well as livestock to ward off Vespa soror, an aggressive species of hornet that gangs up on honeybees. Per the Guardian:

They found these hornets spent less than half the time at nest entrances with dung spotting, compared with clean hives, and 94% less time trying to chew their way in. A final experiment discovered that hives daubed with the secretions that giant hornets use to flag nests for attack were quickly plastered with poo.

After contacting other bee experts, the researchers learned that the spotting behavior is widespread throughout Vietnam and reported in China, Thailand, Bhutan, and Nepal. Some species of stingless bee were known to collect animal feces and incorporate it into their nests, but this was the first report for honey bees.

That’s not all. Researchers wrote in the study they also observed the bees gathering soap scum, and in one case, perhaps smearing a hive in urine:

In addition to animal feces, we saw foragers collecting soap scum and one hive had spots applied to it that were bright blue, but we could not determine their origin. On one occasion, a hive smelled strongly of urine and we found workers visiting a container of human urine nearby.

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The “collection of solid filth” is a previously unobserved behavior in the Apis genus, the researchers wrote. Only stingless bees were previously known to collect filth, and as building material for hives. It’s not clear why the poop was effective at repelling hornets—it’s possible that the hornets simply try to avoid feces in general, that the bees were gathering feces that contained plant matter with specific repellent compounds, or that the stink simply makes it hard for the hornets to smell targets or coordinate attacks. Otis said in a statement that the way the honeybees use animal dung appears to hit several criteria of tool use, in that the bees purposefully hold and manipulate an object from the environment to achieve a specific goal.

“I was shocked [by the use of feces] because bees have such a good reputation for being clean,” Wellesley College professor and study lead Heather Mattila told the Guardian, a shock shared by researchers not associated with the study. “They have hot, wet, permanent homes that are a great place for disease to grow and are filled with babies and food.”

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A murder hornet from Japan being displayed by a Washington State Department of Agriculture pest biologist in Bellingham, Washington in July 2020.

A murder hornet from Japan being displayed by a Washington State Department of Agriculture pest biologist in Bellingham, Washington in July 2020.
Photo: Karen Ducey (Getty Images)

Vespa soror, the species of hornet observed in the study, is a close relative of Vespa mandarinia, another species of hornet native to Asia that has become an invasive species in U.S., and earned moniker the “murder hornet” for its assault on bees. Outside Asia, bees haven’t been exposed to these hornets before, and don’t know how to defend against them. In the U.S., where honeybee populations are already under threat from colony collapse disorder, that brings the prospect that the invasive hornets could wreak havoc if they gain a foothold.

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The first time she heard about Asian giant hornets in the U.S., Mattila added, “I was so worried I couldn’t sleep. I thought, ‘These bees are going to get massacred.’ They just don’t have the exposure to these hornet species and, as a result, they are sitting ducks.”

According to CNN, of the 72 beekeepers surveyed in the study, five kept Western honeybees, which are native to the U.S. Unfortunately, none of those apiarists spotted poop on their hives. Of the remaining 67 beekeepers that kept Eastern honeybees, 63 had hives boasting fecal defenses.

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Washington Scientists Vacuum Murder Hornets Out of First Nest Discovered Stateside

Illustration for article titled Washington Scientists Vacuum Murder Hornets Out of First Nest Discovered Stateside

Photo: Washington State Department of Agriculture

Finally, some good news this year.

Entomologists in Washington have destroyed the first nest of Asian giant hornets, or murder hornets, as they’ve become known in our collective nightmares, discovered in the U.S., the Associated Press reports.

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Crews clad head-to-toe in thick protective gear, looking like they stepped straight out of HBO’s Chernobyl, worked to vacuum the invasive species from the hollow of a tree into bulky canisters on Saturday. If it looks like overkill, remember that these hornets didn’t earn such a terrifying nickname for nothing: Their stings have been described as “like having red-hot thumbtacks” stabbed into you, and the suits keep workers protected from their 6-millimeter-long stingers. The crew came equipped with face shields, too. Because did I mention these things have also been known to spit painful venom into people’s eyes?

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After a weeklong search, the Washington State Department of Agriculture discovered the basketball-sized nest on Friday after outfitting three hornets with radio trackers using dental floss. The nest, which contained an estimated 100 to 200 hornets according to the scientists, was found in the city of Blaine near the Canadian border where several murder hornets have been spotted, the AP reports.

Officials suspect that additional nests could be close by, and will continue searching the area. The tree the nest was found in will also be cut down to suss out any newborn hornets and learn if any queens have already left the hive, scientists said, per the AP. A news briefing on the status of the nest is scheduled for Monday, the agency tweeted.

Asian giant hornets are the largest hornet known on Earth and their queens can reach over 2 inches (5 cm) long. The nickname murder hornet comes from the havoc they wreak on their prey, decapitating bees and other insects with their “mandibles shaped like spiked shark fins” and decimating entire hives in a few hours. Technically, they can survive on tree sap alone, but they seem to prefer munching on colony-living insects instead.

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While these hornets aren’t known to actively attack humans, their stings can be fatal, and up to 50 people a year are believed to be killed by them in Japan, though those estimates vary. They pose much more of a threat to honeybees and, by extension, the farmers that depend on these bees for propagating their crops. In the areas of Asia native to murder hornets, local bee populations have developed a horrifying but effective defense against them (it involves cooking the hornet alive with their collective body heat, and it’s metal as fuck).

Sadly, bees in America, where these hornets began inexplicably popping up in 2019, have no such defense. Scientists in Washington have been rushing to locate the hornets’ nests before their “slaughter phase”—aka when they gorge themselves on prey to prepare for the next stage of their life cycle. Hopefully, the destruction of this nest marks a huge step toward eradicating this invasive species before that happens.

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[The Associated Press]

Just in Time for ‘Slaughter Phase,’ Scientists Find First Murder Hornet Nest in the U.S.

A dead specimen of Vespa mandarinia, aka the Asian Giant Hornet, aka the Murder Hornet, collected by entomologists from the Washington State Department of Agriculture this past July.

A dead specimen of Vespa mandarinia, aka the Asian Giant Hornet, aka the Murder Hornet, collected by entomologists from the Washington State Department of Agriculture this past July.
Image: Karen Ducey (Getty Images)

Entomologists in Washington have confirmed the existence of a nest of Asian giant hornets, more fondly known as murder hornets. The nest is the first such breeding ground discovered in the United States, confirming fears that the invasive species could become established and severely threaten the country’s fragile bee population, as well as possibly attack people. State scientists plan to try destroying the nest this weekend.

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The first U.S. sightings of the Asian giant hornet took place in Washington last winter. This year, scientists began discovering hornets in July. But it wasn’t until entomologists from the Washington State Department of Agriculture were able to trap and capture live hornets earlier this week that finding their nest was made possible. Three hornets in total were outfitted with radio trackers, and it only took a few hours before the nest was found, situated inside the cavity of a tree located on private property in Whatcom County. (The hornets actually prefer nests on the ground, but trees will do in a pinch.) Unfortunately, weather delayed the attempted destruction of the nest scheduled for Friday.

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One of the Asian giant hornets captured by entomologists from the Washington State Department of Agriculture this week

One of the Asian giant hornets captured by entomologists from the Washington State Department of Agriculture this week
Photo: Washington State Dept. of Agriculture

Asian giant hornets are the largest hornet known on earth, with queens able to reach over 2 inches in size. Their murderous moniker is inspired by the devastation they wreak on their prey. Though these insects can survive on tree sap, they love to munch on other colony-living insects, particularly honey bees. It’s thought that a single group of hornets can hollow out an entire beehive of thousands within hours, the only marker left behind being the heads of bees decapitated by the hornets’ relatively huge mandibles. Hornets are big on family, though, so they’ll also save the bee larva of the colony to take home as food for their young.

If that’s not bad enough, these hornets come equipped with enormous stingers filled with potent venom—and they’re not afraid to use them. Hornets don’t actively attack humans, and a single sting is more painful than anything else. But they can be fatal, particularly for people who are allergic to wasp stings. Estimates vary, but up to 50 people a year are thought to be killed by these creatures in Japan. By that same token, though, these hornets are also known to be a delicacy in the parts of Asia where they’re natively found.

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The real danger from the Asian giant hornet isn’t to us, but our bees. The U.S. beekeeping industry has been facing crisis after crisis in recent years, leading to record losses of colonies over the winter. There isn’t a singular cause for these losses, but one crucial factor is thought to be the spread of a voracious arachnid parasite called the Varroa mite. The last thing the country’s bees need is another many-legged bug coming to decimate them.

According to the Washington State Department of Agriculture, the planned destruction of the nest will take place Saturday. The discovery of the nest seems to have been made in the nick of time, as the hornets were preparing to reach their “slaughter phase” soon—i.e. bee feeding time.

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Oh God, These Things Have a ‘Slaughter Phase’

A sample specimen of a dead Asian giant hornet from Japan, also known as a murder hornet, is shown by a pest biologist from the Washington State Department of Agriculture on July 29, 2020 in Bellingham, Washington.

A sample specimen of a dead Asian giant hornet from Japan, also known as a murder hornet, is shown by a pest biologist from the Washington State Department of Agriculture on July 29, 2020 in Bellingham, Washington.
Photo: Karen Ducey (Getty Images)

Washington State officials are frantically searching for a colony of Asian giant hornets—also known as murder hornets—before the invasive species enters its “slaughter phase.” Because of course that’s a thing.

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Washington State Department of Agriculture personnel kicked off a campaign this week to uncover a murder hornet colony following a string of sightings near Blaine, Washington, the New York Times reports. The hornets are about to enter their “slaughter phase,” a period in their life cycle when they descend upon their prey of choice, bees, in droves to harvest them for food, state entomologist Sven Spichiger said in a virtual press conference Friday.

The violent process, in which these hornets are known to decapitate every last bee in a hive, can wipe out entire colonies of honey bees, an already threatened species in the U.S. that farmers depend on for pollinating many of their crops.

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State entomologists found evidence of six hornets in the area this week, leading them to suspect that a nest may be nearby, the Associated Press reports.

“We hope to locate the nest in a couple of weeks and eradicate it,” Spichiger told the outlet.

An agency spokesperson also told the Times that officials caught their first live specimen this week. They intended to equip the hornet with a tracker so as to follow it back to its nest, but their first attempt failed spectacularly. On Wednesday, officials tried to glue a radio tag to the hornet, but not only did the glue not dry fast enough, causing the tracker to slip off, it also stuck to the hornet’s wings and made it unable to fly.

“You do have to be very patient and wait till it dries,” Spichiger said. “But when you’re handling an Asian giant hornet, obviously, it doesn’t want you handling it.”

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The team set up 30 traps baited with orange juice and rice wine throughout the area to try and capture another, the Times reports. At Friday’s press conference, Spichiger said the department was confident it would catch another live specimen within the next few weeks.

“It may be a very daunting task to find the exact location,” he added. “But, you know, that’s what we’re all prepared for, and looking forward to—finding that nest and taking it out.”

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In the meantime, the agency has established an emergency hotline “similar to 911” for beekeepers to contact if their hives come under siege. The department’s campaign encourages beekeepers to “track it, don’t whack it” and take note of which direction the hornets fly toward so as to pinpoint possible nest locations.

A total of 15 murder hornets have been found in the state since spottings first began cropping up in 2019, the department said. In August, officials successfully captured their first two specimens, a queen and a male, proving that their DIY traps worked. Asian giant hornets are the largest in the world at 2 inches (5 centimeters) so traditional hornet traps just won’t cut it.

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As their name would suggest, Asian giant hornets are native to China, Japan, and other Asian countries. Experts are still trying to figure out why the species began appearing in Washington State and the Canadian province of British Columbia last fall, with the prevailing theory being that they may have accidentally hitched a ride on a cargo ship or plane. In addition to being a threat to local bee populations, these hornets can be deadly to humans too. Stings from Asian giant hornet kill an estimated 50 people in Japan every year.