As I mentioned in a previous post, grub damage is evident this time of year. These are some photos from a home lawn adjacent to the golf course that I was called to look at. Much of the turf is dead because the grubs (which in this case are Japanese Beetle larvae) ate the entire root system. You can see the surrounding broadleaf weeds are fine because they didn't feed on those. Again, treating for grubs is very simple...one preventative insecticide application prior to egg hatch (beetle adults lay eggs in early June).
This cup is filled with approximately 50 grubs; all from an area about 2 square feet! Just think, they would all become adult beetles!