Chinch Bugs

Chinch bugs damage St. Augustine lawns. Although you can occasionally find chinch bugs in other grasses, they rarely cause serious injury to anything other than St Augustine. As the insects suck the plant juices, they also inject toxins that cause yellowish-brown patches to appear in lawns. These patches tend to enlarge gradually as chinch bugs expand their feeding area. If the feeding does not kill the grass, it recovers slowly and the damage lasts for a long time. Chinch bugs are sunshine-loving insects and seldom attack grass in shaded areas. Areas of St. Augustine lawns that suddenly become exposed to more sun, because of loss of shade trees, are especially susceptible to attack.

Adult chinch bugs are about one-fifth of an inch long and are black with white wings folded over the back. Newly hatched nymphs are wingless and pink to bright red with a white band across their backs. Older nymphs are black with a white line across their backs.

Check St. Augustine lawns regularly in the warm months of the year by parting the grass in several locations and watching for these insects as they move into the thatch. Another way to check for chinch bugs is to cut the bottom from an opened fruit can, imbed it an inch or so deep in a green area next to damaged turf, and fill it with water. If chinch bugs are present, they float to the top after 5 to 10 minutes. Look closely. These insects are small.