Damage, symptoms and biologyDioryctria 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 informationSimilar 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
Diet and feeding behaviour
: 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.
- Date modified: