Hot and dry. That’s how they like it! “They” are chinch bugs, and this is chinch bug season, when the temperatures soar, and it’s tough to keep up with lawn watering. Chinch bugs can be tough to spot, because 1) they are small, about 1/6 to 1/5 of an inch, and 2) they are quick to hide in the thatch at soil level when disturbed. But their damage is unmistakable. Well, it can be mistaken for lack of water, because chinch bug infested St. Augustine causes the grass to first look wilted, and dries up like straw. If your irrigation system does not have uniform coverage, then dry spots will appear under these hot and dry conditions. Chinch bugs always seem to first go for the hottest, driest part of the yard, along sidewalks, driveways, walls, etc.
Here are 3 easy ways to figure out if chinch bugs are bugging your yard. First, test the irrigation system. If the soil is moist in the “dry spots” after an irrigation, then that is not the problem. A long shanked screwdriver will easily penetrate soil that is moist. Next, if there are patches of dead St. Augustine, check how the weeds, if any, are looking. Pictured here you see dead grass with lush crabgrass. If water was the problem, the crabgrass at least would be wilted. Finally, check the lawn in mid-day. Crouch down so you can get a close look at a small patch of green grass adjacent to the stressed/wilting grass. Fix your gaze on the grass for a minute or 2, and you will notice insects scurrying around. There might be spiders or ants crawling around, but if chinch bugs are present, they will crawl up a grass blade, crawl back down, looking for a spot to feed upon with the piercing-sucking mouthparts.
Here is an earlier blog posting with photos and more on chinch bugs. Don’t let them damage a good lawn.