Description of European pine sawflies
Defoliation of pine trees and shrubs by clusters of European pine sawfly larvae is a common problem in Iowa during the month of May. Larvae of this widespread pest are grayish-green with 2 light stripes and 1 dark stripe on each side of the body. The legs and head are shiny black. Full grown larvae, usually present by Memorial Day weekend, are about 1 inch long.
Damage caused by European pine sawflies
European pine sawfly larvae are gregarious and stay together in a cluster as they feed on the old needles from mugho, Scots and red pine trees and shrubs. Because only old needles are eaten and not the new, emerging growth, defoliated trees are generally not killed. Damage may be aesthetically displeasing, especially in Christmas tree plantations, and growth of the tree may be stunted.
Management of European pine sawflies
Do you live in Iowa and have an insect you would like identified?
The Iowa State University Plant & Insect Diagnostic Clinic will identify your insect, provide information on what it eats, life cycle, and if it is a pest the best ways to manage them. Please see our website for current forms, fees, and instructions on preserving and mailing insects.
Contact information for each states diagnostic laboratory for U.S. residents. If you live outside of Iowa please do not submit a sample without contacting the Plant & Insect Diagnostic Clinic.