The larvae are grayish-green with two light stripes and one 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. European pine sawfly larvae are gregarious and stay together in a cluster as they feed on the old needles. Because only old needles are eaten, defoliated trees are not killed.
Control can be as simple as pruning off and discarding infested branches.
Heavier infestations on larger trees may justify foliar sprays of Sevin, Orthene, or Isotox. Iowa State University , Ames, Iowa. This information subject to a usage policy .