Pine Sawfly Larvae: White Worms Eating Needles in Oklahoma

NE Oklahoma pine trees covered in 1-inch white worms (day-active, night-hidden). Eaten needles fall on deck. Identification and control?

Pest: European Pine Sawfly (Neodiprion sertifer)

• Caterpillar-like larvae of primitive wasps
• Grayish-green with light/dark stripes; 1" long
• Feed in groups on older needles (before new growth)
• Prefer mugo, tabletop, Scotch, red, Jack, Japanese pines
• Rarely kill tree but reduce growth; successive years = decline

Control

Insecticides with residual activity: acephate, malathion, carbaryl, esfenvalerate, rotenone, pyrethrin.