These bugs are diamond shaped, dark brown or black, 1/2″ in size. They hide on the underside of leaves. When they are caught and crushed they emit a foul odor. Squash bugs feed on cucumber, melon, pumpkin and squash. They suck plant juices from the leaves which will show spots that turn yellow and then brown. The stems of affected plants wilt and blacken. Check the undersides of squash plants for egg masses. Pick off affected leaves and destroy them. Get rid of weeds and plant debris around the vegetables. They can be killed by spraying the undersides of leaves with an insecticidal soap.