Squash vine borer
Size: Up to 1 inch long
Where/When: Commonly attacks summer squash, winter squash and pumpkins. Cucumbers and melons are less frequently affected. The larva is active from mid-July through August.
Significance: Serious pest of vine crops. The larva feeds through the center of the stems, blocking the flow of water to the rest of the plant. Plants become wilted, may collapse, and ultimately die.