Origin:
Native to North America, and identified as a pest of crops as early as 1780. They may have originated in southern, more tropical climates and migrated northward as crops were planted.
Biology:
There are 3 species of very similar chinch bugs in the U.S., all in the genus Blissus. Using their straw-like proboscis they feed on the plant fluids of grasses, including turf, corn, wheat, and other crops. In turf they hide within the thatch and feed most often on the crown of the plant and base of the blades. They undergo simple metamorphosis, with 5 nymph stages. As it feeds the chinch bug injects a chemical into the plant that begins to clog the vascular system of the plant, leading to yellowish dead patches on the leaves and ultimately death of that blade of grass. As feeding continues the dead areas of the turf expand outward in small, irregular patches. Damage is most noticeable in open, sunny areas.
Identification:
Adults are about 4 mm long, and oval and flattened on top. The wings are characteristically held flat over the abdomen and folded one over the other. The white veins and the different appearance of the inner and outer halves of the wings give them an “X” marking on top of the wings. The first two nymph stages are red, wingless, and with a white band across the abdomen. The next two instars are orange and show wing pads beginning to develop. The adult has a black body with the white-marked wings held over the abdomen. The adult stage overwinters hidden in some protected area in the landscape, or often within structures in crawl spaces or wall voids. Eggs are deposited by the females in the spring, laying 15-20 per day for several weeks. Egg to adult takes from 1 to 3 months, depending on temperatures, and there are 2 to 3 generations per year.
Characteristicts Important to Control:
This begins with ensuring the cause of the problem by inspecting the thatch for the bugs, which will be at the perimeter of the dead patches. The presence of only a few chinch bugs is not a threat to the turf, and healthy turf can withstand these minor infestations without applications of pesticides. Natural predators and resistant strains of turf can also keep them at bay. Where chinch bugs are a traditional problem an early application of an insecticide to the turf will intercept the over-wintering females before they deposit their eggs. Timing is important, and your local Extension Service can provide information for your region.
