Moths hold the spotlight in first comprehensive guide to Northwest species -Seatle Times

Published – Seattle Times, July 27, 2012

A group of Northwest biologists is creating the first comprehensive guide to the region’s moths.

Butterflies are easy to love, but their night-flying cousins have always been a little harder

Dr. Lars Crabo is an expert in collecting, identifying and cataloguing moths. His extensive, well-organized collection includes orange-and-black Arctia caja moths, which are commonly found in Western Washington. Crabo works as a radiologist.

to cozy up to. A group of Northwest biologists hopes to change that with the first comprehensive guide to the region’s moths.

Far from being a bunch of drab stepsisters, the lesser-known branch of the lepidopteran family includes hundreds of flamboyant varieties and exhibits a degree of diversity that puts butterflies to shame, said Merrill Peterson, the Western Washington University biologist who conceived of the online guide. For every butterfly species in the Pacific Northwest, there are at least six types of moths.

“The sheer number of species makes moths more significant ecologically,” he said.

But they’re also enchanting, said Peterson, a Seattle native who grew up chasing bugs at his family home near Laurelhurst. There are moths that look like hummingbirds and emerge at twilight to sip nectar. Some roll themselves up and masquerade as branches while others hunker down and impersonate a splotch of bird doo. Several species fly during the day. The Polyphemus moth can measure more than half a foot from wingtip to wingtip, while some “micromoths” are smaller than a grain of millet.

Those little guys will have to wait until Peterson and his colleagues expand the guide, which now focuses on more than 1,200 of the region’s biggest moth species. The site includes zoom-able, high-resolution photos and 65,000 records of sightings going back a century or more. There are distribution maps, tips on trapping, and a user-friendly key to identify moths.

“We’ve probably got the most extensive amount of information on these insects that’s available anyplace,” said collaborator Richard Zack, who oversees Washington State University’s collection of 3.5 million insects. The website is designed so anyone can use it, Zack said — from teachers and students to farmers and folks who just want to know what’s flitting around the porch light.

Introducing more people to moths and their astonishing variety was one of Peterson’s goals. Another was pulling together historical and baseline information in order to track population trends as habitats change and climate fluctuates.

“If we’re going to be able to notice the changes around us, we need to be in touch with the natural world,” he said. Helping people put names to the moths they see around them will build familiarity, and watchfulness. “It’s hard to care about something if you can’t stick a name on it,” Peterson said.

The guide was made possible by a world-class moth collection in WWU’s backyard. In the tradition of 19th-century gentleman naturalists, Bellingham radiologist Dr. Lars Crabo has amassed nearly 40,000 specimens over the past several decades.

As a boy in Sweden, Crabo organized his friends into insect-hunting parties. He rekindled the passion after moving to the United States in high school, though serious moth collecting requires so much gear he couldn’t start until he got his first car. Now Crabo hauls his lights and bucket traps in a pickup he calls the mothmobile.

“It’s one of those things you can’t explain,” he said. “These moths are beautiful to me.”

He’s discovered about 40 new species, naming one for his wife and one for his daughter. Another collector named a species for Crabo.

Most of the specimens photographed for the guide are from Crabo’s collection. Oregon State University scientists helped compile the sighting reports and other data, a task that took three years.

The project was funded by $500,000 in National Science Foundation grants under the federal stimulus package. The work generated eight full- and part-time jobs, Peterson said. But the project’s most lasting value will lie in its usefulness as an educational tool and a source of practical information, Zack said.

Beautiful though they may be, some moths are pests, particularly in their larval forms. A better understanding of the species they’re dealing with will help farmers and homeowners mount a more effective defense, Zack said.

For example, there’s a big difference between the corn-ear worm, a moth caterpillar that can devastate a crop, and the false corn-ear worm, a harmless wiggler that feeds on weeds. Farmers bait traps with pheromones and start spraying as soon as the first moths turn up, Zack said. But the harmless variety usually arrives up to a month before the pest. Farmers who spray too early are wasting money.

“Our website will hopefully allow them to differentiate,” Zack said.

Peterson hopes to eventually add more categories of moths until the guide encompasses all of the region’s approximately 2,000 species. Moth-hunting and photography is enjoying a burst of popularity, leading to this week’s designation as the first National Moth Week. So Peterson is optimistic citizen scientists will help improve the site with their discoveries.

“If anybody finds a weird moth or has data to share, we’d love to hear from them.”

Sandi Doughton: 206-464-2491 or

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