Green Pug Moth (GPM) : New England Tree Fruit Management Guide : UMass Amherst

Pasiphila rectangulata

Overview

Green pug moths have been found in New England since the 1990s. The yellow-green larvae are inchworms that bore into flower buds at bud break and feed, causes blossoms to abort. One larva can damage several flowers and, where numerous, can significantly reduce fruit set.

Biology

GPM overwinter as eggs on apple trees, hatch at bud break, and enter buds to feed. Young larvae are olive green with black heads and look like winter moth young larvae.
Larger GPM larvae are green and develop a dark red-brown stripe along the back.
Most larvae finish feeding by Petal Fall, pupate in folded leaves, and emerge as adult moths in June and July.

Monitoring

Examine flower buds for caterpillars at Tight Cluster to early Pink. Tentative treatment threshold is 6 or more GPM larvae per 100 fruit clusters.

Management

Apply insecticide at early Pink if exceed threshold.

Mature green pug moth caterpillar (red stripe) and winter moth caterpillar (Photo H. Faubert)