Billbug

Billbug larvae feed inside grass stems and on roots, creating irregular brown patches in lawns that pull up easily because the root system is destroyed. You will notice the damage resembles drought stress, but the turf does not recover with watering. Adults are small, dark weevils with a distinctive snout, active from late spring through summer in Western Washington lawns.

Maintain vigorous turf through proper mowing height, fertilization, and irrigation to help grass outgrow larval feeding damage. Overseed with resistant grass varieties where billbugs are persistent. Entomopathogenic nematodes applied as a soil drench in late summer target larvae in the root zone. Avoid broad-spectrum insecticides that disrupt natural enemies.