Hemlock adelgid

Hemlock adelgids infest western hemlock and mountain hemlock foliage, though populations in Western Washington rarely cause visible damage due to host tolerance. You may observe small, dark aphid-like insects at the base of needles; they produce a waxy, white filament. Unlike the destructive eastern hemlock woolly adelgid, this insect is believed to be endemic to the Pacific Northwest and exists in ecological balance.

Monitor hemlock trees for adelgid presence if concerned about potential spread. No control is warranted in Western Washington since native hemlock tolerates the insect well and robust predator populations naturally suppress outbreaks. Avoid broad-spectrum insecticides that disrupt beneficial predators. Maintain tree vigor through appropriate cultural practices.