Billbugs
Billbug adult
Photo courtesy of Clemson University
Billbug larvae are legless white grubs. They measure about 3/8” long and are very fat, with a larger tail end than head end. The head capsule can vary from orange to brown in color. Adult billbugs are weevils that can vary in color from dark gray to black. They are also 3/8” long and have a long snout.
Damage
Damage occurs in the larval stages. The larvae burrow downward inside the grass stems and chew on the stem base, crowns and roots. Injured plants break off easily at the crown when pulled. A fine, light brown “sawdust” is visible in the root zone and on the broken stems of affected plants. Damage can be seen as spotty patches of yellow or dead grass. Injury frequently occurs near sidewalks and driveways, but entire lawns can be affected.
In northern areas, the Bluegrass billbug favors Kentucky bluegrass and does its damage from July to August. In the south, the Hunting billbug favors Zoysia, and occasionally Bermuda and does its damage from June through October. Central and Midwestern states have both species of billbugs.