Pest profile

Silver-Spotted Tiger Moth

Lophocampa argentata · Lepidoptera: Erebidae[2]

Silver-spotted tiger moth caterpillars feed in dirty-looking webbed tents on Douglas-fir and other conifers through fall and winter; their hairs can irritate skin.[1]

Silver-spotted tiger moth with brown forewings covered in silvery-white spots
Silver-spotted tiger moth with brown forewings covered in silvery-white spots. (c) Doug Macaulay, some rights reserved (CC BY) — via iNaturalist, CC BY 4.0

How to identify it

  • Caterpillars reach 1.5 inches and are mostly reddish brown with some blue-black or yellowish hairs.[1]
  • Adults are brownish or tan moths with a 2-inch wingspan and distinct silvery, translucent spots on the wings.[1]
  • Eggs are round and emerald green, laid in clusters on needles at branch tips.[1]

Where it lives

The PNW Insect Management Handbook covers it in Pacific Northwest landscapes, and there are reports of it defoliating forests.[1]

US map: public records from 9 states since 1990 (GBIF).

Biology and life cycle

In fall, tiny white larvae spin small webs at branch tips and overwinter in dense clusters, feeding on warm winter days.[1]

Webs and damage grow more noticeable by spring; in June mature caterpillars wander onto other plants, patios and decks looking for a place to spin cocoons.[1]

Cocoons are woven from silk and the caterpillars' reddish-brown hairs.[1]

Douglas-fir is preferred, but pine, arborvitae, spruce and true firs are also attacked.[1]

Damage and signs

  • Caterpillars eat needles under their webs, but buds aren't harmed and spring growth usually covers most damage; minor infestations do little harm to landscape trees.[1]

Health risk

The hairs can irritate skin when caterpillars are handled without gloves, and rubbing your eyes can embed hairs painfully in eye tissue.[1]

Control

Traps and physical control

Prune out and destroy tents with caterpillars, wearing gloves.[1]

Biological control

Ophion parasitoid wasps and tachinid flies, including the large Tachinomyia similis, make populations crash in landscapes.[1]

Common questions

What are the webs on my Douglas-fir branch tips in winter?
Likely silver-spotted tiger moth caterpillars, which feed in webbed tents through fall and winter.[1]
Why are fuzzy reddish-brown caterpillars crawling on my deck in June?
Mature silver-spotted tiger moth caterpillars leave trees in June to find places to spin cocoons.[1]

Sources

  1. Pacific Northwest Pest Management Handbooks (OSU, WSU, University of Idaho), “Douglas-fir (Pseudotsuga): Silver-spotted tiger moth (Insect Management Handbook).” pnwhandbooks.org/insect/hort/landscape/hosts-pests-landscape-plants/douglas-fir-pseudotsuga-silver-spotted-tiger-moth (accessed 2026-10-06)
  2. iNaturalist, “Lophocampa argentata taxon page (order and family).” www.inaturalist.org/taxa/84792 (accessed 2026-10-06)

Updated 2026-10-14. Built from sourced records. Spot an error? Tell us.