Discovering and Exploring the Leaf-feeding Insects in Our Region

Pacific Northwest (PNW) Defoliators

Defoliator News

Argyresthia pruniella, the cherry blossom moth

(5 June 2014)

The cherry blossom moth is a new tiny moth with larvae that feed on developing fruit. Only know from the United States since 2011, we are still observing this species to see if it will become a pest problem. Learn more about it here: cherry blossom moth




Tortricidae Image Gallery!

(26 Dec 2013)

One service Entomologists frequently provide is identification of potentially serious exotic pests. This can be challenging, since specimens submitted for identification are often very damaged and wing patterns are not visible, and because there are many native moths that can resemble target pests. Sometimes, the internal genitalia - which can be very distinctive between species - is the only identifying characteristic available. Several websites have been developed that make identifying moths much easier (check out Tortricids of Agricultural Importance and Pacific Northwest Moths). With a new image gallery composed of specimens from the WSDA reference collection, we hope to provide an additional resource that makes imagery of many native tortricid species available, including figures of male genitalia. We have also provided an index of species captured in traps targeting important pest species. This website is still being developed, and we hope to improve the interface significantly over the next year. Some improvements will include a scrolling thumbnails page that scales to the user's screen size, and a search bar and alphabetical index to make it easier to find particular species. Please feel free to email us with your suggestions for making this a more useful resource.

Red Lily Leaf Beetle - Pest Alert!

red lily leaf beetle

(28 Jan 2013)

There is yet another introduced defoliator to be alert for, one which might be a serious problem for Pacific Northwest gardeners. The red lily leaf beetle (Lilioceris lilii) is a bright red beetle in the family Chrysomelidae, with a voracious appetite for lilies. Introduced to Canada from Europe in the 1940s, the species was thought to be restricted to the northeastern states and Canada. In spring of 2012, the species was discovered in the Bellevue, WA area. More information can be found in this pest alert from Washington State University Extension ( These beetles are relatively easy to recognize - if you think you see them, please help us track their spread by contacting one of these people with your information:

Sharon Collman, Washington State University Extension

Todd Murray, Washington State University Extension

Chris Looney, Washington State Department of Agriculture

Lilioceris lilii, adult Lilioceris lilii, larvae Lilioceris lilii, eggs



Green Alder Sawfly - Pest Alert!

green alder sawfly
photo by A. Karankou

(8 June 2010)

A newly discovered pest, the green alder sawfly (Monsoma pulveratum), was detected in Washington State this spring by Andrei Karankou of Vancouver, WA. The following news release from Skamania County Extension has more information:


Skamania County, Wash. -

The Green Alder Sawfly was first detected in the lower 48 states of United States this spring in Vancouver, WA. Now green caterpillar-like larvae of the sawfly insects can be found eating the leaves of alder trees along the Columbia River in Skamania County. Entomologists from the US Forest Service and Washington State Department of Agriculture are surveying for the new insect in Western Washington State.

"When green alder sawfly was first found in April, we had hoped to eradicate a small infestation in Vancouver," said Kathy Sheehan, entomologist with the U.S Forest Service. "Thanks to an informal network of entomologists, though, we soon found this sawfly throughout western WA. Now we will be watching closely to see what effect this non-native species has on alders."

The green alder sawfly is native to Europe and Western Eurasia in addition to parts of North Africa. It was first discovered in Newfoundland, Canada in the mid-1990's and first collected in Alaska in 2004. The green alder sawfly is an accidentally introduced pest of alder trees.

Larvae of the green alder sawfly resemble bright green caterpillars and grow up to ½- ¾ inches long. The larvae chew holes in leaves and can defoliate a tree if sawfly populations are high enough. The adults are active in early spring and resemble a wasp without the stinger and constricted waist.

Experts are uncertain of the impact that this new insect will have on alder tree health or on our local flora and fauna. As with any organism newly introduced to our region, there is a concern that economic and environmental damage to our forests could result.

For more information about the Green Alder Sawfly, visit Green Alder Sawfly or contact the WSU Extension office at 509-427-3931

Check out the Species FAQ page to see more pictures of the green alder sawfly.


New Species Added to the FAQ:

We've added several species to our rogue's gallery of defoliators, including new records for the State of Washington. Check them out here: Species FAQs


Introducing the Western Region Lepidoptera Diagnostic Center

USDA-APHIS and WSDA have teamed up to provide Lepidoptera identification services for specimens collected west of the Mississippi. Begining in August, 2009, the "WRLD" Center is ready, willing and able to identify moths collected by Cooperative Agricultural Pest Surveys, and other government and extension efforts - just send us your bugs! Please contact us for submission guidelines.


New Teachers Resource!

(02/08/2010) Teacher's Lesson Plan

Spring is here, and it's a great time to learn about the insects around us. This simple (and inexpensive) lesson plan is available to help teachers plan laboratory and class exercises that take advantage of nature in our backyards.


Introduced European Saw Flies in Washington???

(note: species is Neodiprion sertifer)

Article from: What's That Bug?

Pine sawfly

(05/30/2008) Please help us if you can!
I live in a condo association. Today we discovered these insects in several of our small pine cone bushes. There are hundreds and hundreds of them in all the bushes. If you could identify this caterpillar or worm I would VERY much appreciate it. Most of them are totally black and smoth and slimy like a snake and about 1 inch in length. Here is a picture: Looking forward to a reply at your earliest convenience! Thank you so much!
Gail Phillips
Bellingham, Washington

Hi Gail,
We believe you need to contact your local Department of Agriculture Insect Pest Control division. Call 360-902-2070 or email because we believe you have the Introduced European Saw Fly, Diprion similis. This introduced species is known in the eastern U.S., but we cannot find any indication that it has become established in Washington. BugGuide reports it as far west as Wisconsin. If you have an isolated outbreak, control might still be possible. The University of Georgia Forest Pests website indicates: "The introduced pine sawfly occurs from Canada to North Carolina, and in the central and lake states. Eastern white pine is its favored host, but it also attacks Scotch, red, jack, and Swiss mountain pines. Infestations of this insect can be very serious in young plantations of white pine grown for timber products or Christmas trees." Several days ago we received a letter from Michigan regarding this species.

Probable Confirmation: (06/02/2008) Sawfly larvae on Whatcom pines
Hi Gail (and others…)
The larvae are likely the European pine sawfly, and yes, the occurrence of the species is the first for Washington State (and Western U.S.). However, the species has been in neighboring British Columbia, Canada, for some time, including areas of the Frasier River delta which is not far from the Bellingham area.

I appreciate your interest and efforts to bring the situation to our attention. I am in the process of getting some of the larvae (with help from the County Extension office) to get confirmation of the species and would be glad to let you know if/when that happens. Thanks again for the contact.

Todd Murray

Thanks so much for your Email and information contained therein regarding our occurrence of this recent troubling 'event'. Yes, we would very much be interested in continuing updates regarding this 'infestation'. Also, many thanks to for their immediate response to my inquiry in helping to identify this particular species! Sincerely,
Gail Phillips



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