Pest Information: Chinch Bugs

The southern chinch bug, Blissus insularis (Barber), is the most damaging insect pest of St. Augustinegrass. It will occasionally feed on other grasses including bermudagrass, bahiagrass, zoysiagrass, and centipedegrass. The distribution of B. insularis ranges from southern North Carolina south to the Florida Keys and westward to central Texas. Damaging populations have also been reported in southern California, Mexico, and Hawaii.

The hairy chinch bug, Blissus leucopterus hirtus (Montandon), is a serious pest of cool season turfgrasses. Preferred hosts are fine fescues, perennial ryegrasses, bluegrasses, bentgrass and zoysiagrass. These grasses are also susceptible to damage by the common chinch bug, Blissus leucopterus leucopterus. The physical appearance of these species is very similar and it is difficult to positively identify which species is infesting cool season turf. The hairy chinch bug is distributed through eastern Canada and the northeastern United States as far south as Virginia and west to Minnesota.

The Buffalograss chinch bug, Blissus sp, is a common pest on Buffalograss and resembles the hairy chinch bug.

Adult chinch bugs are black with white wings and are 3.0-3.6 mm long. Some adults possess short, non-functional wings. Chinch bugs develop through five nymphal instars. First and second instars of the southern chinch bug are bright orange while the third and fourth instars are dark red and the final instar is black and closely resembles the adult. First and second instars of the hairy chinch bug are bright red; the third instars are orange; the fourth instars are orangish brown; and the final instar is black. The eggs of all species are white and oval with a blunt end and measure 0.25 X 0.75 mm.

Chinch bug development is temperature dependent, and eggs may require as little as one week to hatch during the summer but may require more than a month during the spring. Nymphal development typically requires four to six weeks during the summer. Southern chinch bugs produce three to seven generations per year, depending on the geographic location and weather. Hairy chinch bugs produce two generations per year from southern New England through the Middle Atlantic states and west to Ohio. One generation of hairy chinch bugs is produced per year in upstate New York and southern Ontario, Canada.

Chinch bugs damage turf by inserting their piercing-sucking mouthparts into the crowns, stems and stolons of grass plants to remove sap. During this process they inject a toxin that causes the grass to turn yellow. Thus, damage appears as irregular yellow patches of turf. These areas turn reddish brown and eventually die, while the chinch bugs move outward into healthy turf. A yellow halo around the damaged area is typical of a chinch bug infestation. Damage from chinch bugs shows up first in sunny areas with heat or drought stressed grass and which is often areas near pavement or sidewalks. Although damaging infestations commonly occur from June into September, weather conditions may prolong this period, especially in the range of the southern chinch bug. In south Florida, all stages of the southern chinch bug are present during the entire year.

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