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Identification
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.
Hosts
All turfgrass species
Damage
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.
Monitoring
information
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.
Management
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
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