Woolly Apple Aphid Infestation on Mature Apple Tree

Identification

White, powdery/waxy coating on branches of a 20-year-old apple tree in Northern California, easily washed off, is woolly apple aphid (Eriosoma lanigerum). Their waxy covering resists dormant oil. They can damage branches and cause sooty mold on fruit.

Targeted Treatment

Use a product like Conserve SC (spinosad) which is effective on aphids and allows fruit consumption. Apply per label. Monitor for reinfestation. Consult the Cornell IPM fact sheet for detailed biology.