The host range of black grass bugs is quite broad. Most damaged plants will eventually recover if there is adequate moisture, but drought conditions coupled with severe black grass bug damage may cause some plant mortality. Heavy infestations may prevent seed formation, and black grass bugs often are pests of grass seed production fields. Certain amounts of damage to the leaves seem to repel cattle or make the grass unpalatable. Damaged leaves may appear straw colored, as if they have been damaged by frost. Most feeding is done on the upper surface of the leaf. The bugs begin feeding at the leaf tip and proceed downwards, feeding with the head pointing down. Within seconds of the start of feeding, a whitish spot appears at the site from the destruction or removal of chlorophyll. Immature stages are similar in appearance to the adults, but smaller.Д«lack grass bugs damage plants in the spring by piercing and sucking the contents of cells. brachycera is jet black in color, with no markings. hesperius has buff coloration on the outer margins of the wing covers. Black grass bugs are about 1/4 inch in length when mature and black in color over most of the body. Thirty-four species of Labops and Irbisia are known from North America. A second species, Irbisia brachycera (Uhler) may be locally abundant. Several species of black grass bugs exist in Colorado, with the most common being Labops hesperius Uhler. Even moderate infestations of black grass bugs may offer significant competition with livestock for rangeland forage.

Losses in heavily infested range may exceed 90 percent of the forage. Monocultures of these grasses provided a habitat that was conducive to population explosions. The first reports of damage to range grasses were in 1938, when many western ranges were seeded with introduced wheatgrasses. The bugs apparently caused little damage to native plants before rangeland improvements were attempted. These small black bugs are native to western rangeland, being first collected by the Hayden expedition in Colorado in 1871. Cultural and chemical control measures may be effective for many seasons if timed correctly.Д«lack grass bugs have caused considerable damage to certain western range grasses over many years.Black grass bugs compete directly with livestock for forage grasses and may be major problems in some areas and years.Problems are especially obvious on roadsides seeded with wheatgrasses. Severe infestations are primarily associated with rangeland reseeded to introduced wheatgrasses.Black grass bugs are native to western rangelands and exist at low populations on native range.

Black bugs