Sawfly Larvae on Red Pine: Identification and Control

Not Caterpillars—Sawflies

Greenish-black "worms" eating older pine needles in groups are sawfly larvae (related to wasps). They don't eat new needles.

Damage & Risk

• Defoliation of older needles slows growth but rarely kills trees.
• Repeated years of heavy feeding can weaken trees.

Control

• Mechanical: Clip infested branches, bag and destroy; or knock larvae into soapy water.
• Chemical: Spray foliage with acephate, malathion, carbaryl, esfenvalerate, rotenone, or pyrethrin for larger infestations.

Timing

Treat when larvae are small and actively feeding (spring/early summer).