How to Manage Pests

Distinguishing the larvae of clearwing moths from American plum borer

Distinguish American plum borer larvae from clearwing moth larvae by using a hand lens to examine the crochet pattern (arrangement of small hooks) on the bottom of the prolegs (leglike appendages) on their fourth abdominal segment:

1. Clearwing larva have crochets in two transverse rows (rows are oriented perpendicular to the insect's body length).
2. American plum borer crochets are more dense and form a complete circle or oval. The plum borer's prolegs are also more narrow than clearwing prolegs when compared with the width of their abdominal segment.

Adapted from Peterson, A. 1956. Larvae of Insects. Part 1. Ann Arbor, MI: Edwards Brothers.

Proleg crochets: A. Clearwing, B. American plum borer