Gall aphids are small, grayish or greenish insects that
feed in distorted tissue or in galls. Two common gall
aphid species are the manzanita leaf gall ahid, Tamalia
coweni, and the poplar petiolegall aphid, Pemphigus sp.
Foliage feeding by gall aphids causes swellings
or galls to form on leaves. Galls are not damaging to trees.
Galls are not damaging to trees. No management
Poplar petiolegall aphid in poplar gall
Manzanita leaf gall aphid damage