What should I do, if anything.

Reporter
June 8, 2010, 7:29 a.m.

Hi Roy, thanks for your report. Initially, I suspect this may be a native moth, as we have several moths that create these tents, including the silver spotted tiger moth. However, I have forwarded your report on to entomologist Jim Labonte at the Oregon Department of Agriculture, and he will best be able to determine the species. It can be difficult, however, to determine species from caterpillars, as the species can look quite similar. I'll let you know what Jim says.
Lisa DeBruyckere, Oregon Invasive Species Council Coordinator

Lisa DeBruyckere
June 8, 2010, 10:44 a.m.

Roy, see the response from Jim LaBonte at ODA:

These are a native species, the western tent caterpillar, which feeds on a wide variety of broad leaved trees and shrubs. They rarely cause significant damage. If the plant is of high value, spraying the nest with high velocity water to break it apart or using appropriate pesticides will suffice. Otherwise, they are nothing to be concerned about. Periodically, they have outbreaks where they become quite numerous and cause substantial defoliation, but this is a short-lived phenomenon with little significant impact. Diseases, parasites, and predators catch up to them in time and reduce the numbers dramatically. By the way, gypsy moth caterpillars do not make webbing or silken tents. James R. LaBonte, Taxonomist, Oregon Dept. of Agriculture

Lisa DeBruyckere
June 21, 2010, 2:13 a.m.