Squash bugs feed on all members of the cucurbit family, which includes cucumbers, melons, pumpkins, and summer and winter squash. The adults overwinter in garden debris and begin laying eggs in early summer. The best way to reduce squash-bug numbers and their damage is by killing their eggs before they even have a chance to hatch. Follow these easy steps to help keep these pests out of your garden. (Whether you're starting your first garden or switching to organic, Rodale’s Basic Organic Gardening has all the answers and advice you need—get your copy today!)
First, find the eggs. Squash bugs lay eggs on the undersides of leaves in evenly spaced groups. Get in the habit of scouting your squash plants for the shiny, yellowish brown to reddish eggs. Also, keep your eyes peeled for the small, light gray or green, wingless squash-bug nymphs, which suck on the plant's sap, causing the leaves to wilt, blacken, and die.
Now squish 'em. Kill the squash bug eggs by gently rubbing them back and forth with your fingers, making sure to not damage the leaf. Squash bug nymphs are also often present near squash bug eggs. If you see any squash bug nymphs, be sure to squish them, too.