First U.S. Sighting of Massive Atlas Moth Confirmed

The insect may have escaped from an illegal cocoon-selling operation

Atlas moth in Bellevue shown to be the size of a human hand
A homeowner spotted the moth on the wall of his garage in early July. Courtesy of Washington State Department of Agriculture

A homeowner near Seattle made the find of a lifetime this summer when he walked outside and spotted a massive, dark-orange moth clinging to the wall of his garage. He snapped a photo of the beautiful creature, using his hand for scale, then fired off an email to Patrick Tobin, an entomologist at the University of Washington.

When Tobin read the message, he almost couldn’t believe his eyes. He replied immediately, asking the homeowner to nab the insect before it flew away. The homeowner was at work, but he raced the 45 minutes back to his home in Bellevue to capture the moth in a bag, which Tobin promptly drove over to pick up.

Now, experts have identified the mysterious insect as an Atlas moth (Attacus atlas), one of the largest moth species in the world, and they’re asking the public to keep an eye out for any more of these colorful insects. This July 7 sighting in suburban Seattle is believed to be the first confirmed incidence of the moth in the United States, per a statement from the Washington State Department of Agriculture (WSDA).

Atlas moth on a leaf
The Atlas moth's orange wings have markings that resemble the head of a snake. Darrell Gulin/Getty Images

With wingspans that can reach up to 10 inches, Atlas moths are native to tropical regions like India, Indonesia and the Philippines, which makes the sighting in the Pacific Northwest especially bizarre.

“It's like if all of a sudden you saw a black rhino walking down [the interstate],” Tobin tells KUOW’s John Ryan.

Atlas moths are federally quarantined pests, which means it’s illegal to “obtain, harbor, rear or sell live moths, whether adults, eggs, larvae or pupae without a permit” from the U.S. Department of Agriculture, per the WSDA.

It’s not exactly clear how the Atlas moth found its way to the Pacific Northwest, but scientists have a pretty good guess. Someone with a Bellevue-based account was selling Atlas moth cocoons on eBay for $60 each. The listing has since been taken down, but Tobin suspects the Atlas moth likely escaped from that illegal seller, reports the Seattle Times’ Amanda Zhou.

As of now, this individual sighting doesn’t mean there’s an infestation. But the state’s agriculture department is asking the public to photograph, collect and report any Atlas moths they see out and about, which will help determine if there’s actually a population of them in the area.

If more Atlas moths have made their way to Washington, that could spell bad news for the region’s fruit-growing industry. The adult moths are harmless—they don't have mouths—but as caterpillars, they feast on the leaves of apple and cherry trees, which would pose a threat to the state’s fruit growers.

With their intricately patterned wings and large size, the moths would be pretty hard for members of the public to miss. Only the white witch moth (Thysania agrippina) has a larger wingspan, at around 14 inches. And Atlas moths are believed to have the largest wing area of all known moth species, reports Gizmodo’s Lauren Leffer.

Atlas moth appears larger than three native moth species
This graphic from the Washington State Department of Agriculture shows how to distinguish Atlas moths from other species. Courtesy of Washington State Department of Agriculture

Their wings taper down at the top and have markings that resemble the head of a snake, which is a useful disguise for confusing hungry predators.

Entomologists aren’t even sure if Atlas moths could survive the weather of the Pacific Northwest, but they don’t want to take any chances. The state is working with the USDA to further investigate the moth sighting and determine how best to respond, if at all.

Anyone who spots one, whether in Washington or elsewhere in the country, should report the moth to WSDA or their state’s plant regulatory officials.

“This is a ‘gee-whiz’ type of insect because it is so large,” says Sven Spichiger, WSDA’s managing entomologist, in a statement. “Even if you aren’t on the lookout for insects, this is the type that people get their phones out and take a picture of—they are that striking.”

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