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.
chinch bugs (R.A. Casagrande)
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.
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.
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
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.
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.
from the University of Massachusetts Extension, 1999