The squash bug (Anasa tristis) is a perennial and severe pest of pumpkins and squash; it rarely injures cucumbers and melons in the Midwestern United States.
Squash bug adults are brown, flat-topped, and 3/4 inch long. The nymphs are gray, flattened, and up to 3/4 inch long. The eggs are reddish brown and laid in clusters on the leaves.
Both the nymphs and adults suck sap out of leaves, stems, and fruit of squash and pumpkin. Feeding by large numbers causes vines to turn brown and black and then dry up. Heavy feeding on the fruits causes them to collapse and be unmarketable.