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Dioryctria moth

Dioryctria moth -
  • Latin name: Dioryctria pseudotsugella Munroe
  • French name:
  • Order: Lepidoptera
  • Family: Pyralidae


British Columbia

This species is generally distributed throughout British Columbia from the Skeena and upper Fraser drainages south; it also occurs south to California and New Mexico.



Damage, symptoms and biology

Dioryctria pseudotsugella is a common, occasionally abundant, innocuous solitary defoliator.

Mature larva up to 15 mm long. Head, brown unmarked. Body, brown, dorsum rusty brown; narrow creamy white subdorsal and spiracular stripes; broad dark supraspiracular stripe.

This species appears to overwinter in the egg stage. Larvae are present from May to July; pupation occurs in July and adults emerge from July to August.

Population fluctuations synchronous with those of the western spruce budworm.

Other information

Similar species: Dioryctria reniculelloides is similar but differs in that the colour of the dorsum and subspiracular stripe is much duller; it also has different host preferences.

Canadian Forest Service Publications

Dioryctria moth

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)

The principal host of Dioryctria pseudotsugella is Douglas-fir; other hosts include western hemlock and grand fir.

Main host(s)

Douglas-fir, Rocky Mountain Douglas-fir

Secondary host(s)

Amabilis fir, Engelmann spruce, Rocky Mountain juniper, subalpine fir, western hemlock, western redcedar, white spruce, white spruce


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