What is it? The yellow-headed spruce sawfly is a native North American insect with a distinctive dark yellow head. It attacks spruce trees, consuming new and then old needles, which can cause severe defoliation and death. Symptoms Damages What to do? Other resources: https://www.calgary.ca/parks/pests/yellow-headed-spruce-sawfly.html https://tidcf.nrcan.gc.ca/en/insects/factsheet/7875