Bark Boring Moths
What are they?
Are they here yet?
Yes, all three of these species have been found in Washington. Cherry bark tortrix continues to spread and build populations as it moves south in western Washington, but hasn’t yet been detected in eastern Washington. It currently infests most cherry and plum trees from Olympia north to Canada and is increasing its attacks on apple trees as well. Isolated populations now occur south as far as Salem, Oregon, having spread that far since their first detection near the Canadian border in 1991. The European apple clearwing moth has been found in Whatcom County and the eastern dogwood borer occurs in Chelan, Douglas, and Spokane Counties.
For more information on where surveys have been conducted for wood-boring insects in the Puget Sound Basin, see map.
Why should I care?
Bark boring moths attack trees in the rose family including apples, cherries, plums, apricots, almonds, peaches, laurels, and many others. Damage from these pests can kill trees or at the very least make them more susceptible to other bacterial and fungal diseases, frost damage, and other insect pests.
Cherry bark tortrix attacks fruit trees in the Pacific Northwest causing noticeable dieback and wilting in the canopy of trees.
The apple clearwing moth is native to Europe and damages host plants via larval feeding in the bark and on the trunk and branches. Larvae tunnel under the bark from below the crown area up to the branches.
The eastern dogwood borer larvae feed in the bark of host trees causing decline or death.
What should I do if I find one?
How can we stop them?
To help stop the spread, do not move fruit trees and rootstocks from infested areas. If you have trees from the rose family in your yard, be on the lookout for these species and for damage they may have caused on your trees. If you find potential evidence of these pests, please contact your local Washington State University Extension office, or the Washington Department of Agriculture to get more information or help with identification.
What are their characteristics?
Cherry bark tortrix
- Forewings have dark and light browns specks or spots.
- Wings have strips of orange, dark purple, and silver.
- Larvae are caterpillar-shaped and usually are transparent, with a pinkish lining in the gut.
- Mature larvae reach the lengths of 1.5 inches and the eggs are very small, oval, and salmon pink.
European apple clearwing
- Larvae are .78 inch to 1 inch long with a reddish-brown head.
- Pupa are a pale yellowish-brown and the adults have a wingspan of .78 inch to 1 inch.
- They have a dark blue-black body with an orange-red band across the abdomen.
- Their wings are transparent.
Eastern dogwood borer
- They are clear-winged moths and have wasp-like bodies, about .5 inches long.
- Adults are bluish-black with a yellow band on their abdomens.
- Eggs are small (.02 x .02 inch), oval, and marked with a pattern of slightly raised lines. Initially pale yellow, the eggs turn darker with development.
- Larvae are cream colored with reddish-brown heads with two reddish-brown spots. Larvae grow to a size of more than .6 inch when fully grown.
- Pupae are light brown, .4 inch long, and inside a cocoon made of silken thread and frass fragments.
How do I distinguish them from native species?
Please contact your local Washington State University Extension office or the Washington Department of Agriculture for help with identification. Also, visit the information sources listed below for more detailed identification characteristics.