Southern Ag Malathion 50 E.C. is labeled to treat aphids, spider mites, cucumber beetles and leaf hoppers on squash but the product label does not specifically list squash bugs.  Sevin Concentrate is labeled for squash bugs and many other insects on edibles such as vegetables, fruit trees as well as flowers, shrubs, lawns and the exterior perimeter foundations of the home. Please view the full product label for more information.