BIOLOGY: Mature larvae are small, green caterpillars with three dark stripes running the length of the body.  The caterpillars are about 10 mm (approximately 3/8 inch) long and will wriggle vigorously when probed or otherwise stimulated.  Adults are small (17mm or 2/3 inch), brownish moths.  Overwintering adults lay eggs on the plants in early spring.  Larvae emerge in early May, feed through July, pupate and emerge as adults in late summer.

DESTRUCTIVE STAGE: Larvae (leaf feeding)

IMPACT TO HOST: Larvae attack poison hemlock by rolling leaves and feeding on foliage, flowers, and buds.

REDISTRIBUTION: Larvae can be collected in late June and early July using picking leaf rolls off of plants. A typical release is 250 adults.Â