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University
of Rhode Island GreenShare Factsheets
Chinch
Bugs Blissus
spp.
Hemiptera: Lygaeidae
Chinch
bugs are a complex of three different species within the Lygaeidae
family. They have piercing-sucking mouthparts and they feed on the
sap of grass plants. They reside in the thatch area of the turfgrass
stand and prefer to feed on the lower leaf sheath and crown area
of the plant. The chinch bug can be a major insect pest on home
lawns throughout the country. The hairy chinch bug (Blissus hirtus)
is the most common species in the Northeast. The hairy chinch bug
prefers bentgrasses, but will attack many other lawn grasses as
well. The adult chinch bugs are about 3 to 5 mm (1/8 to 1/5 inch)
in length and black with white markings on the wings. The wings
rest flat over the back of the insect and there is a black spot
between the wings. Adults may be long-winged or short-winged. There
are five nymphal instars of chinch bus ranging in size from 1 to
3 mm (1/32 to 1/5 inch). The first two nymphal instars are red,
with a white band across their abdomen, while the third and fourth
instars are orange with wing pads just beginning to appear. The
fifth instar is black with wing pads easily visible.
The chinch bug inserts its straw-like mouthparts into the plant
tissue and sucks out the plant juices while injecting chemicals
into the plant which clog the vascular system. The area around the
feeding puncture usually turns yellow. Damaged areas first appear
as small, irregular patches which enlarge as the insects spread.
Chinch bugs are most damaging in open, sunny areas.
Chinch bugs spend the winter as adults in partially protected areas
(under shrubs or around foundations of houses). As the weather warms
in the spring, adults move into open areas, where females begin
laying eggs. Fifteen to 20 eggs per day are deposited for two to
three weeks. The eggs hatch in one to two weeks, and the nymphs
begin to suck the juices from host plants. It takes 30-90 days to
reach adulthood. There are two generations per year, with a partial
third generation in unusually warm summers. There is considerable
overlap of generations, and all stages can be found during the summer.
Examine the grass in the marginal areas of injured patches, not
in the clearly dead grass. Spread the grass gently with your fingers
and look in the thatch, near the soil surface. Chinch bugs are usually
very active in the summer, so you will be able to see them scurrying
around, especially on warm summer days. An alternative method of
detecting chinch bugs is to remove both ends of a large tin can,
such as a coffee can. Soften the soil a little with water, and insert
one end of the can into the ground at least 5 to 8 cm (2-3 inches)
deep, leaving at least 10 cm (4 inches) of the can above the ground.
Fill the can with water and wait about five minutes. If chinch bugs
are present, they will float to the surface of the water, where
you can count them. In many instances,
chemical control of chinch bugs is not necessary. Studies in Michigan
have demonstrated that lawns which receive adequate amounts
of water
throughout the summer (preferably weekly deep waterings) are able
to tolerate relatively high populations of chinch bugs without
sustaining
damage. In addition, many lawns have natural populations of predators,
such as ground beetles or "big-eyed bugs," which can keep chinch
bug populations from getting out of hand. Insecticide applications
sometimes have very adverse effects on these predators, causing
the chinch bug populations to develop more rapidly in subsequent
years. Plant
resistance has also been reported for a number of turfgrass species
and cultivars. Research has demonstrated strong resistance of endophyte-enhanced
turfgrasses to the hairy chinch bug. Turfgrass managers
usually control chinch bug populations after major damage has occurred.
To avoid this problem in areas with habitual problems, an April
to mid-May insecticide application will control the overwintering
females and subsequent generations during the summer. Reinfestation
may occur from adjacent areas, but this process is slow and may
require an additional year or more. This adult treatment must be
made before egg laying occurs. As with any pesticide application,
be sure to read the label and apply the material at the specified
rate. Avoid mowing the area for two or three days afterward. Adapted
from the University of Massachusetts Extension, 1999
Pesticides
are poisonous! Read and follow all safety precautions on labels.
Handle carefully and store in original containers out of reach
of children, pets or livestock. Dispose of empty containers
immediately, in a safe manner and place. Pesticides should never
be stored with foods or in areas where people eat.
When trade names are used for identification, no product endorsement
is implied, nor is discrimination intended against similar materials.
Be sure that the pesticide you intend to use is registered for
the state of use.
The user of this information assumes all risk for personal injury
or property damage.
For more
information, call the URI CE Gardening and Food Safety Hotline
at 1-800-448-1011 or (401)874-2929 from outside Rhode Island;
Monday-Thursday between 9 am and 2 pm.
University
of Rhode Island Cooperative Extension provides equal program
opportunities.
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