Pest description and damage Adult moths are brownish or tan with distinct silver-white spots on the wings. The caterpillars can reach 1.5 inches in length and are mostly reddish-brown with some blue-black or yellowish hairs. The caterpillars of the silver-spotted tiger moth feed on the needles, often "tenting" branches with dirty-looking webs. While most of the feeding occurs through fall and winter, the webs are most noticeable in the spring. Minor infestations cause little harm to trees. Douglas-fir is the preferred host, but pine, arborvitae, spruce, and true firs also are attacked.
For biology, life history, monitoring and management
Douglas-fir (Pseudotsuga)-Silver-spotted tiger moth
See "Caterpillar" in:
See Table 2 in: