Greenheaded spruce sawfly
- French common name: Tenthrède à tête verte de l'épinette
- Scientific name: Pikonema dimmockii Cresson
- Kingdom: Animalia
- Phylum: Arthropoda
- Class: Insecta
- Order: Hymenoptera
- Family: Tenthredinidae
Distribution
- Canada
Damage, symptoms and biology
The greenheaded spruce sawfly is common and is frequently found together with the yellowheaded sawfly but is considerably less damaging.
Mature larva to 20 mm long. Head, green marked with black stripes along the vertex and sides. Body, green with prominent white addorsal and spiracular stripes.
This species overwinters as a prepupal larva in a cocoon buried in the duff or subsoil. Adults emerge in May and lay their eggs on the new flush. Larvae initially feed on the current year's needles then move onto the old needles. Larvae are active from mid-June to July when they drop to the ground and spin overwintering cocoons.
Canadian Forest Service Publications
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)
Photos
Cocoon
Thérèse Arcand
Lateral view of mature larva, on Engelmann spruce
Lateral view of mature larva, on Engelmann spruce