Cool-season-mite
Guides
Oligonychus ununguis
spruce spider mite
Oligonychus ununguis, commonly known as the spruce spider mite, is a globally distributed pest of coniferous trees, particularly spruce. It is considered one of the most important pests of spruce plantations in Ontario and causes significant damage to ornamental conifers. The mite feeds on needle sap, causing foliage discoloration, and produces silk webbing that accumulates dust. Populations thrive in cool spring and autumn conditions but decline during hot summer weather when temperatures exceed 85°F.