Michigan State University Extension
Ornamental Plants plus Version 3.0 - 00001568
11/12/99
Controlling Lawn Insects
Bluegrass Billbug
Adult billbugs are dull gray to black or brown beetles
with a snout or bill. The larvae (Vis. 1) are white,
humpbacked grubs with a yellow to brown head.
Symptoms are irregular patches of dead grass, especially
near sidewalks or curbs. The dead grass pulls out easily
and has hollow stems. The larvae are present under the
grass and brown sawdust-like frass is present in the root
zone. The adults can be found in the grass near the dead
areas.
Larval controls should be applied in June. Use pesticides
labeled for use on grubs. Only heavily infested lawns
should be given pesticide applications.
Chinch Bugs
The adults (Vis. 2) are small, black bugs 3/16 inch long
with white wings. The larvae are smaller than adults,
wingless, brick red in color with a white band on the back.
It is the feeding of the larvae in late July that is most
damaging. The injury is irregular shaped yellow patches, 2
to 3 feet in diameter, which turn brown and die out.
Non-grass plants may survive in the affected area. The
insects keep moving out from the infested area so are most
likely to be found at the edges of the spots.
Chinch bugs are usually not serious on well watered
lawns so watering properly will help control them. Severe
infestations will require applications of pesticides.
Apply the chemicals according to label directions.
Sod Webworm
The larval stage causes the damage. The larvae are
grayish brown to dirty white and have 4 parallel rows of
dark brown spots on the abdomen. The adults are grayish
tan moths that fly in a zig-zag pattern in the evening.
The symptoms are brown patches where the grass blades
are missing and not simply dead. The larvae can be found
in silk-lined tubes they have made in the thatch layer.
White Grubs
White grubs are the larval stage (Vis. 3) of one of several
beetles. The most common white grub seen in the soil is
the C shaped larvae of the May or June beetle. European
Chafer larvae have become a serious a problem in lawns.
These larvae feed on the grass roots and when numerous can
cause dead areas in the lawn.
Symptoms are dead areas in the lawn. The grass in the
affected area can sometimes be easily pulled out. Roll
back a section of sod to see how many grubs are under the
lawn. If many grubs are found, controls may be necessary.
Frequent irrigation may help infested lawns cope with grub
populations.
Information summarized from the following Michigan State
University Extension publications.
E-2496 Turf Tips for the Homeowner-Hairy Chinch Bug
E-2497 Turf Tips for the Homeowner-Bluegrass Billbug
E-2498 Turf Tips for the Homeowner-Sod Webworm
E-2499 Turf Tips for the Homeowner-White Grubs
E-2500 Turf Tips for the Homeowner-European Chafer
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This file was generated from data base ZZ on 01/19/00.
Data base ZZ was last revised on 11/12/99.
For more information about this data base or its contents please contact
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