A properly maintained lawn that has been spared repeated doses of broad-spectrum insecticides naturally supports many kinds of beneficial insects. Under normal conditions, they effectively control most pest insect populations without our even being aware of their activity. However, there may be times when drastic pest control action is necessary, and there are several products that can be used as a last-ditch treatment for a severe webworm problem.
Avoid using any lawn insecticide containing granular diazinon. While this product is effective against many lawn insects, it is known to kill songbirds, ducks, and geese if it is allowed to sit on the surface of grass turf or soil. It has been banned from use on public golf courses for that reason.