Pine Oak Sawfly

From Bugwoodwiki

USDA Forest Service. 1979. A guide to common insects and diseases of forest trees in the northeastern United States. Northeast. Area State Priv. For., For. Insect and Disease Management., Broomall, PA. p. 123, illus.

The pin oak sawfly feeds on the lower surface of oak leaves, leaving only the upper surface and a fine network of veins. Defoliation first appears in the upper tree crown, but complete defoliation can occur by the end of September. The preferred host is pin oak, but other red oaks and white oak may be affected.

Adults are small, shiny-black, four-winged insects. The yellowish-green larvae or slugs are about ½ inch long. The thoracic legs and head are shiny black. Larvae and adults may be found almost anytime between May and September. Two generations per year are produced as far north as New Jersey.