Insects in Lawns

Black cutworm larva in turfgrass.

However, certain insects may occasionally damage or kill turfgrass. Insect feeding can cause grass to turn yellow or brown or die, especially if the grass is already stressed. Damage usually begins in small, scattered patches, which may merge into large dead areas. Insects that may cause damage in California lawns include various root-, crown-, and leaf-feeding caterpillars; grubs, which include the larvae of scarab beetles such as the black turfgrass ataenius and masked chafers (white grubs); billbugs, which are weevils with white, grublike larvae; and chinch bugs. Vertebrate predators such as skunks, raccoons, wild pigs, and birds may be attracted to turf infested by insects, especially white grubs in autumn, and cause further damage by uprooting grass in search of their prey. 

To assist you before taking any insect control action, see the newly revised Pest Note Lawn Insects by Andrew Sutherland (UC Statewide IPM Program, SF Bay Area), Ali Harivandi (UC Cooperative Extension, Alameda County (retired)), and Steve Dreistadt (UC Statewide IPM Program). This publication will help you identify whether insects are causing the damage and not something else and provide information about the insect life stages susceptible to control actions.