INSECT
CONTROL:
Insects can occur even in a healthy lawn and it is impractical to
attempt to control them all. Insecticides are most effective when
used at specific periods in an insect's life cycle, but only consider
their use if severe lawn damage is threatened. Mite
problems in turf grass are related to drought conditions. These
insects damage the plants by sucking out their juices. A serious
mite problem can usually be prevented by providing adequate water.
Only garden sprays containing a miticide should be used. Common
insecticides do not affect mites, but do kill insects that feed
on mites.
White
grubs chew the roots of grasses causing them to die from lack
of water. Peak injury by grubs often takes place in late summer
and early fall.
The
most effective time to use insecticides is shortly after the eggs
hatch and the grubs are small (usually early August). Large grubs
are immune to most insecticides and lawn thatch can temporarily
prevent insecticides from reaching the grubs. Diazinon, Sevin, and
Oftanol are among the more effective white grub insecticides.
Adult
stages of white grubs are beetles known as "May," "June," or "Japanese"
beetles or chafers. These are most commonly seen in late spring
and early summer during which time they lay eggs.
The
grub (larva) stage of the billbug chews the roots and tunnels into
the developing crown area of grasses, leaving little piles of sawdust-like
debris. Damaged grass dies out in spots and the blades pull easily
from the plant when given a simple tug. Peak damage usually occurs
in early summer as the grubs grow larger.
Although
it is young grubs that do the damage to the lawn, it is difficult
to control the billbugs during this stage. However, adult billbugs,
a type of snout beetle, are present during April through May in
most areas and can be controlled with Dursban, Sevin, Diazinon,
and Oftanol, The object is to kill the billbugs before they have
a chance to lay eggs.
Chinch
bugs damage lawns by sucking sap from the leaves and injecting
a saliva which further damages the grass. Their greatest injury
is caused in lawns suffering from drought. These black and white
insects can be detected by sinking a bottomless can into the soil
and filing it with water. Within a few minutes (5 -10) the chinch
bugs will float to the top.
Insecticides
which are effective against chinch bugs include Diazinon, Sevin,
and Oftanol.
Sod
webworms are caterpillars which live and feed in silk-lined
tubes they form in the grass. Clipped grass that fails to green
in spring may indicate sod web worm infestation. Also, flocks of
starlings or other insect-feeding birds often indicate high populations
of sod webworms or other insects. To diagnose these insects, drench
the lawn with dilute (2-4%) dishwashing detergent. This irritation
will cause them to come to the lawn surface.
Dursban,
Sevin, Orthene, Ofanol and Diazinon are effective treatments best
applied late in the day, a day or two after mowing.
