Common name: Chinch Bug
Scientific name: Order Heteroptera, family Lygaeidae, Blissus Spp.
Size: Adult—1/16" to 1/5"
Identification: Black bodies with white wings with triangular marks on the back. Emit an odor when crushed. Eggs white to dark red, laid in the soil. Nymphs are red with white stripes across the back. Look similar to the beneficial bigeyed bug. Primarily found on St. Augustine lawns.
Biology and life cycle: Incomplete metamorphosis. After hatching, the wingless nymphs are red, then orange, then black, developing a bright-colored band across their back. Two or three generations a year. Adults hibernate in grass.
Bigeyed Bug Adult
Habitat: Lawns; corn and other agricultural crops.
Feeding habits: Feed the most in heat of summer and early fall. They suck the juice from grass leaves through needlelike beaks. They inject toxic saliva into the plant that causes wilting. Most damage is caused by the nymphs and shows up in circular patterns. They like hot conditions and stressed turf.
Economic importance: Turf damage, especially to St. Augustine. Foliage turns yellow, then brown, then dies. Almost never a problem in well-maintained turf.
Natural control: Healthy soil and turf. When weather turns cool in the fall, a beneficial fungi called Beauveria spp. moves in and kills these pests. It appears as a grayish cottony mass of fungal hyphae. Keep lawns moist and don't over fertilize. Bigeyed bugs are a natural enemy.
Organic control: Diatomaceous earth and compost. Manure tea, molasses, and citrus oil spray.
Insight: Sinking a coffee can with the bottom cut out into the turf and filling with water is supposed to be a way to detect chinch bugs. We question how well this works. Chinch bugs are rarely a problem when turf is kept moist and well maintained.
Note: A friend of Malcolm Beck spread a lawn with hot compost—some that was still strong with ammonia gas—on a warm summer day; the chinch bugs came to the top by the millions and left the area.