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Billbug adults are small weevils, 1/3 inch (0.8 cm) long, with
long, downward-pointing snouts and elbowed and clubbed antennae.
They are often seen walking on paved areas but are difficult to find
in turf. Larvae are creamy white, 3/8-inch-long (0.9-cm-long) grubs
with brown heads. The absence of legs distinguishes billbug
larvae from other turfgrass pests.
All turfgrass species
Billbugs first feed on the inside of turfgrass stems and crowns,
then move to feed on roots. The affected area appears brown, thin,
and dead in small, irregular spots. Damage can spread to patches
extending many feet in width. Fine, whitish, sawdustlike frass can
be observed on the soil surface. Damaged turf breaks at the crown
and is easy to pull from the soil, but cannot be rolled up like sod
damaged by white grubs.
Look for billbugs during the spring, summer, and fall. Dig around
roots for whitish, C-shaped, legless grubs up to 3/8 inch (0.9 cm)
long with reddish heads. Look for piles of frass at the base of turfgrass
plants. Inspect outdoor lights around dawn for 1/3 inch (0.8 cm)
brownish to gray snout beetles. Look for adults crawling around sidewalks.
Follow recommended irrigation and fertilization
rates for your turf species. Mow at the high end of the recommended
height for your species. If more than 1 billbug per square
foot is found, you may need to treat the area with an insecticide. Beneficial
nematodes are effective against grubs.
For more information on lawn insects, refer to:
Pest Notes: Lawn Insects