European pine sawfly

Mature larvae are grayish green, 18–25 mm long, and caterpillarlike in appearance. They have three pairs of thoracic legs and seven pairs of fleshy abdominal prolegs on the lower side of the abdomen. Mature larvae have shiny black heads and five characteristic stripes that run parallel along the length of their bodies. On each side of the body are two adjacent stripes; the one nearest to the legs is dark green or black and the stripe located right above it is grayish green. A light green stripe runs directly down the middle of the back of a mature larva. The eggs appear as an even spaced row of light brown spots along the length of a pine needle. Adults are wasplike, brown to black, and approximately 10-12 mm long.