Most of the grubs are now pupating and/or emerging as the adult beetles so applying some poison to control them now will do nothing. Grubs are the larva of beetles and if you have small white, or light brown, moths flying up from the turf you probably have another problem, not grub related so treating for grubs would be a waste of your money since that is not the problem.
If you dig into the turf at the edge of the "bad" area and make a 1 foot square (_) type of cut and roll back the sod and count the number of grubs you find (10 or more per square foot is a problem, 5 or less is not), and if you also take a largish can (a 3 pound coffee can works well) and cut both ends out and work that can into the soil a bit, at the edge of the problem area again, and partially fill that with water and find a lot of wee, whitish colored wiggly things floating in that water, that is your problem, the larva of those moths.