Pickleworms grow to about 3/4-inch long.

This caterpillar is mainly a problem in the southeastern United States. It feeds on the blossoms, stems, and developing fruits of summer squash, and occasionally cucumbers and muskmelons. The adult moths emerge in spring after overwintering as pupae in semitropical areas such as southern Florida. They migrate northward to lay eggs on leaves, buds, stems, and fruits of susceptible plants. There may be four or more generations per year depending on the climate.

Control

After harvest, pull up and destroy vines, leftover fruits, and nearby weeds, all of which serve as overwintering sites for the insect. Plant as early as possible in order to harvest crops before late summer when damage is usually greatest. Spray with Bacillus thuringiensis (Bt) in late spring.

Photography by Clemson University - USDA Cooperative Extension Slide Series, Bugwood.org