Chinch Bug
Blissus leucopterus leucopterus (Say), Lygaeidae, HEMIPTERA

DESCRIPTION

Adult-The adult chinch bug is about 4 mm long and black with opaque wings. The wings may be as long as the body or 1/3 to 1/2 the length of the body. In either case, each wing bears a distinctive, triangular, black mark.

Egg-The egg, approximately 0.84 x 0.30 mm, is flattened at one end which bears three to five minute projections. The egg gradually changes in color from pale yellow to red before hatching.

Nymph-The wingless nymph is smaller than but similar in shape to the adult. The head and thorax are brown; the eyes are dark red; and the abdomen is pale yellow or light red with a black tip.


BIOLOGY

Distribution-The chinch bug is found from the east coast into the western plains of Nebraska, Kansas, Oklahoma, and Texas. Specimens have been examined as far north as Maine, Wisconsin, Minnesota, and South Dakota, and as far south as Louisiana and Alabama. Confined primarily to the Midwest, damaging infestations can be associated with above-normal temperatures and below-normal rainfall between March and October in the Southeast.

Host Plants-Chinch bugs attack many forage, lawn, and wild grasses. The principal crop plants damaged are spring barley, wheat, corn, sorghum, Sudan grass, rye, timothy, and, to a lesser extent, winter barley and oats.

Damage-The chinch bug pierces the plant with its four-jointed beak and sucks out the plant sap. This feeding prevents normal growth and results in dwarfing, lodging, and yield reduction. Severe infestations during early development may cause plants to wilt and die prematurely. Most injury is caused by the six nymphal instars.

Life History-Chinch bugs overwinter as adults in various protected areas, particularly among weeds and grasses near fields. Adults emerge in the spring and deposit eggs singly behind the leaf sheath or in the soil at the base of the small grain crop plant. In a few days, the eggs hatch and the nymphs begin feeding on all parts of the host plant from the roots to the uppermost leaves. The nymphs undergo six developmental stages, the last being the adult stage. Two to three generations occur per year, the later generations migrating to corn and sorghum when small grain crops become dry.


CONTROL

Since chinch bugs attack only grass crops, crop rotation, especially with legumes, is an effective cultural control practice. Chinch bug feeding is also deterred by a vigorously growing crop. Therefore, cultural practices -- timely seeding, ample fertilization, and thorough weed control -- help prevent chinch bug damage. Some varieties of corn and sorghum offer resistance to this pest.

If chinch bugs do invade in economic numbers, they must be controlled chemically. For specific control recommendations, consult the North Carolina State Agricultural Extension Service.