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Filament bearer

Filament bearer - Dorso-lateral view of mature larva, on western redcedar
  • Latin name: Nematocampa resistaria (Herrich-Schaffer)
  • French name: Nématocampe
  • Order: Lepidoptera
  • Family: Geometridae




Needle, Scale

Damage, symptoms and biology

The filament bearer is a common solitary defoliator, occasionally causing noticeable defoliation. During outbreaks considerable mortality may occur in understory western hemlock.

Mature larva to 21 mm long. Unique caterpillar with two pairs of white tipped tentacles on the dorsum of the second and third abdominal segments. Head, mottled rusty brown. Body, rusty brown with prominent paired dorsal tubercles on the first and eighth abdominal segments.

This species overwinters in the egg stage. Larvae are present from June to July, pupation occurs in July or August, and adults emerge about two weeks later.

Life cycle (West of the Rockies)

Life cycle (West of the Rockies)
Stage/Month J F M A M J J A S O N D

Canadian Forest Service Publications

Filament bearer

Diet and feeding behaviour

  • Phyllophagous : Feeds on the leaves of plants.
    • Free-living defoliator: Feeds on and moves about freely on foliage.
Information on host(s)

Main host(s)

Engelmann spruce, grand fir, Rocky Mountain Douglas-fir, subalpine fir, tamarack, western hemlock, western larch, western redcedar, western white pine, white spruce


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