Green Pug

By Chris T. Maier
Department of Entomology
The Connecticut Agricultural Experiment Station
123 Huntington Street
P.O. Box 1106
New Haven, CT 06504-1106
Telephone: (203) 974-8476 Fax: (203) 974-8502
Email: Chris.Maier@ct.gov  

The introduced green pug is a potential pest of apple and pear trees. This geometrid moth, a native of Europe and Asia, was first detected in North America in Nova Scotia in 1970. By the early 1980's, the pug had spread to Maine. By 1997, it had reached Connecticut. Since 1997, the green pug has become common throughout Connecticut. In the eastern United States, the green pug now inhabits New England, New York, and New Jersey. The moth also occurs the Pacific Northwest.

Damage: In spring, the caterpillars feed upon buds, flowers, and occasionally developing leaves. When they are abundant, the caterpillars reportedly can defoliate fruit trees, causing reduced growth and loss of crop. To date, the caterpillars have not damaged trees in sprayed Connecticut orchards.

Host Plants: In the Northeast, the caterpillars feed upon at least 30 species of trees, including apple and crabapple (Malus, 23 species), pear (Pyrus, 5 species), and shadbush (Amelanchier, 2 species). In Europe, they also have been reported to feed upon cherry (Prunus) and hawthorn (Crataegus). In Connecticut, the caterpillars are most abundant on unsprayed apple and crabapple trees.

Life Cycle and Appearance: The green pug has one generation per year, spending the winter as an egg. The caterpillars hatch from the gray oval eggs (1/16" by 1/10") in early April of most years. They feed upon buds, flowers, and developing leaves, binding flower parts or leaves together with silk to make a shelter. The caterpillars complete their growth by mid-May at which time they are yellowish green with a purplish red or green stripe down the center of their back. When they are full-grown, they are 3/8-1/2" in length. The caterpillars form pupae under loose bark of tree trunks or in the soil under trees. The grayish adult moths, which have a wingspan of 5/8-7/8", emerge 2-3 weeks later, usually between the last week of May and the second week of June. Between late May and early July, the females lay eggs singly near the buds on twigs. The eggs remain dormant until the following spring.  

Summary

The introduced green pug is a potential pest of apple and pear trees.