Background

Western Tent Caterpillars (Malacosoma californicum pluviale) periodically occur in high numbers in Western Washington. Sometimes, the beautiful forest caterpillar, Malacosoma disstria, can become quite populous too. "Out breaks" can occur every 3-7 years depending on weather and other factors. During the spring and summer of 2003, many communities around the Puget Sound experienced high numbers of tent caterpillars. Washington State entomologists are predicting another year with large numbers of tent caterpillars in 2004.

This web site is intended to offer education about the biology, pest status and management of tent caterpillars. This information will aid homeowners and pest managers around Puget Sound in making pest management decisions, safely and effectively. Please use the drop down menu up to the left side of your screen or the text links at the bottom of the page to find the information that you are interested in. Click on any of the images to see a larger image. You can also navigate using the text links below. Feel free to contact us if you have any questions.

Entomologists, Mark Hitchcox (USDA-APHIS) and Eric LaGasa (WSDA) inspect damage on this young cherry tree. The presence of three tents resulted in nearly complete defoliation. Picture taken mid-June, 2003. Blaine, WA