Damage

• Squash bugs don't carry diseases, so the only damage the plant receives is at the feeding site. Squash bugs feed by piercing the leaves and sucking out fluid. This causes small yellow spots that eventually turn brown. Vigorous plants can withstand quite a bit of feeding by squash bugs, but serious infestations may cause the leaves to wilt, eventually resulting in the death of the plant.
  
  

Insecticides

• With good cultural and physical controls it isn't usually necessary to use insecticides against squash bugs. If you find members of the squash family wilting in the presence of squash bugs early in the season, use an insecticide containing carbaryl or rotenone. Use only products labeled for squash bugs and follow the label instructions carefully. It isn't necessary to treat squash bugs found late in the season, regardless of the number of bugs.
  
  

Other Controls

• Healthy plants resist damage from squash bugs. Physically remove squash bugs by knocking or dropping them into a bucket of soapy water. Check the undersides of leaves for eggs and squash them when you find them. Lay out boards in the garden. Squash bugs will congregate underneath the boards at night and you can remove them early in the morning. Pick up plant debris around the garden to eliminate hiding places and remove plants when they are through producing for the year.