Watch out for the
bluegrass bill bugs!
Adult beetles are often seen on sidewalks and driveways on sunny spring
days. The larvae or grubs are 1/4 to 3/8 inches long when mature. The
grubworms are white and legless with a brownish head. The matured adult
beetles are 1/4 to 3/4 inches long with hard shells that range in color
from gray to black to dull yellow.
Adult beetles chew holes into the grass stems to deposit their eggs in
the spring. Hatching larvae feed within the stem and hollows it out. As
the larvae mature they move down into the soil and feed on the roots.
This root damage is never severe enough to loosen the turf from the
soil. Even so, damaged stems from the larvae easily break away at the
crown and are filled with a sawdust like material. Billbug damage is
often misdiagnosed for drought damage, delayed spring green-up, dollar
spot, chinch bug or white grub damage.
Insecticides are effective for controlling both the adult beetle and the