Overview
Pear psylla is one of the more problematic insect pests of pear. It is widely distributed, has several generations and life stages, has an unusual ability to develop chemical control resistance, and secretes copious amounts of honeydew that grows a black fungus making fruit un-marketable. Heavy infestation can also result in tree stunting (psylla shock), reduced fruit set and size, and even death with prolonged infestation.
ID/Life Cycle
Pear psylla is a cicada like insect that feeds on pear trees and overwinters as an adult. This adult form is slightly different from its summer form. Winter adults are black and larger than summer adults. Summer adults are striped and reddish-brown. Eggs are laid in rows, are small and ovoid and appear creamy white when first laid but become yellow to yellow orange at maturity. Overwintered adults emerge from hibernation when spring temperatures warm to 45-50°F. Before tissue growth occurs eggs can be found at the base of buds but may be laid along shoots as well. Later eggs are laid along leaf midveins.
Management Strategies
Monitoring:
Look for pear psylla adults on the first nice sunny day of spring before bud break. winter-form adults; use a beating tray and threshold of an average of 0.2 adults per 10 samples in an acre or less (20 samples in blocks larger than an acre). Adult psylla can also be monitored using sticky traps. summer treatment threshold for pear psylla is one nymph/three leaves. Examine 25 spurs (one per tree) and terminal shoots per orchard to determine the threshold average.
Date: July 2021
Author(s): Elizabeth Garofalo, Jaime Piñero, UMass Extension
Note: This information is for educational purposes only and is reviewed regularly for accuracy. References to commercial products or trade names are for the reader’s information. No endorsement is implied, nor is discrimination intended against similar products. For pesticide products please consult product labels for rates, application instructions and safety precautions. The label is the law. Users of these products assume all associated risks.
This work was supported in part by funding provided by USDA NIFA Extension Implementation Program, Award No. 2017-70006-27137
