Chinch bugs are dark in color and have wings. They are almost microscopic in size, similar to the size of a sesame seed. The best way to tell in they are affecting your property is to look closely for movement in the lawn at the leading edge of the damaged area.
Chinch bug damage often looks like and is mistaken for Summer drought stress or Brown Patch on your lawn. It should not be assumed that if your lawn is browning in a certain area that this damage is either of those. Chinch bugs move quickly and cause extensive damage. They primarily damage areas that have well drained soil or in open areas that get full sunlight.
Mid-May to Mid-June is usually the best time to apply an insecticide to target these insects.
Read More: https://ag.umass.edu/turf/fact-sheets/chinch-bugs