Pear psylla

You will see tiny yellowish insects with piercing-sucking mouthparts on pear foliage from early spring through fall. Heavy infestations produce abundant honeydew that causes fruit russet and leaf sooty mold. Nymphs cluster on buds and leaves. Damage includes stunting, defoliation, and unmarketable fruit. Pear psylla overwinters as adults and is the most challenging pest for Washington pear growers.

Monitor egg hatch in spring as buds swell. Time dormant oils or insecticidal soaps for early season when crawlers are vulnerable. Maintain vigilant scouting throughout the growing season to prevent population buildup. Predatory insects including minute pirate bugs and parasitic wasps attack psylla. Avoid broad-spectrum insecticides that kill beneficial insects essential for pear psylla control.