Threelined larch sawfly
Damage, symptoms and biologyThe threelined larch sawfly is a common solitary defoliator. Damaging outbreaks have not been recorded in British Columbia.
Mature larva up to 15 mm long. Head, yellowish brown with black eyes. The larvae are tapered caudad with the thorax larger than the abdomen. Body, green marked with a faint middorsal pinstripe and well-defined olive green addorsal, supraspiracular, and epipleural stripes.
This species overwinters as a prepupal larva in a cocoon buried in the soil. Adults emerge in late May and the females lay eggs, usually singly, into slits cut into the needles. Larvae are present from mid-June to July. Mature larvae drop to the ground and spin cocoons in late July.
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 threelined larch sawfly is restricted to tamarack.
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