Have you ever had one of those patches of grass that just didn’t seem to respond to water or fertilizer? It may not be a lack of water, it just might be an tiny insect known as a Chinch Bug (Blissus insularis). Chinch bugs are primarily a problem in St. Augustine grass lawns mostly in the coastal areas of the state. Symptoms of chinch bug damage are characterized by expanding irregular patches of dying or stunted St. Augustine grass. In some cases, a halo of yellowing to orange St. Augustine grass will be observed at the outer edges of the dying grass. Chinch bugs prefer lush, actively growing St. Augustine grass that is found in hot spots of the lawn such as next to driveways and sidewalks.
Adult chinch bugs have small, black bodies with white wings. The nymph (immature) stage of the chinch bug is wingless, yellow to pinkish-red in color with a light colored band across the back. The nymph stage of the chinch bug can be found feeding underneath the leaf sheath of the turf grass plant. While feeding on the grass, the chinch bug injects a salivary fluid into the turf grass plant that disrupts the water conducting system of the plant, causing it to wilt, turn yellow, and then turn brown and die. It normally takes 22 to 25 chinch bugs per 1,000 sq.ft. to cause damage to the St. Augustine grass. Generally, if there are enough chinch bugs to cause damage, they can easily be found moving around in the St. Augustine grass.
Chinch bugs can be controlled chemically with a variety of different products that will need to be spread on to the affected area. Listed below are some of those products which are readily available at your local lawn and garden center or feed store.
| TRADE NAME | ACTIVE INGREDIENT |
| Orthene T/O | Acephate Ortho Systemic Insect Killer |
| Talstar Lawn and Turf
Ortho Bug-B-Gon Max Insect Killer Total Kill Lawn & Garden Insect Killer (granules) |
Bifenthrin |
| Spectracide Triazice Once & Done Insect Killer (granules) | Lambda-cyhalothrin |
STAGES OF CHINCH BUGS
CHINCH BUG DAMAGE IN ST AUGUSTINE
For more information about Chinch Bugs or other lawn and garden questions, contact the Texas A&M AgriLife Extension Service of Austin County at (979) 865-2072, or click on the Ask the Expert tab.
Prepared by Philip Shackelford, PhD
County Extension Agent for Agriculture & Natural Resources
Texas A&M AgriLife Extension Service of Austin County
