Chinch bugs are small, black and white critters that will literally suck the life from a lawn. They prefer St. Augustine grass, but will also feast on Bermuda, Zoysia, and Centipede grass. Chinch bugs like it hot and dry. For this reason, a lot of the damage occurs next to streets, driveways, and sidewalks. Grass damaged by chinch bugs remains attached to its roots, unlike grub damage. They cause irregular patterns in a lawn as opposed to fungal issues that are circular in nature. Before you start spraying or spreading your insect killer of choice, you need to identify the cause of your problem.
Chinch bugs are surface dwelling creatures and they are easily detected. Remove the top and bottom of a steel can. Push it into the soil at the edge of the healthy and damaged grass and then fill it with water. The chinch bug will swim to the top. Then count the bugs. This link will provide you with the number you don’t want to see.
Ok, you found more chinch bugs than average. Now we start to control them. All-natural products include DE (Diatomaceous Earth) or my favorite, orange oil. On the synthetic side, I like Cyonara spray (lambda-cyhalothrin) and Kill-a-Bug (permethrin).