Billbug and chinchbug activity is continuing in some areas, although the bluegrass billbugs appear to be nearing the end of their larval activity. So the worst should be over for this year. Chinchbugs are well into their second generation this year. Remember that billbug and chinchbug damage resembles drought stress, but the affected turf does not recover in September when the temperatures moderate.
Normally if adequate rainfall (0.5 to 1.0 inch per week) or adequate irrigation is received throughout the summer chinch bug activity is masked. The insects may be present, but because the turf is able to grow vigorously, it can outgrow the insect damage.
This summer has been anything but normal, so if you suspect damage the best thing to do is aerate and over-seed damaged areas with endophytic perennial ryegrass varieties at 6 – 8 lbs. per 1,000 SF, best if done between August 15th – September 15th.