Another huge issue we face in the summer, particularly August, are insects that damage grass both above and below the ground. I highly recommend you treat for them now to avoid problems in the future.
The main insect that attacks lawns across the United States during the summer is the grub worm. Grubs are the larvae of the Japanese Beetle or Junebug. They are hatched in July and feed on grass roots during August and into November. They can devastate lawns, especially if their numbers get out of hand.
If you are going to treat for grub worms, make sure you get a product that contains the ingredient “Merit.” This will give you long lasting control through the summer and into the fall.
Sod Web Worms
Sod web worms are surface feeding insects that can cause some browning in lawns during the summer, especially in the Midwest. You know you have a sod webworm infestation if you see moths flying up and out of the grass when you walk on it. These are the adults, and they don’t do any damage, but their larvae do.
I have not seen much activity with billbugs in my area until this year. These guys start feeding on the surface and then burrow through grass crowns and begin feeding underground, very much like Japanese Beetle grub worms. If you have bill bugs, you need to apply an immediate-acting insecticide like Dylox.
All of these guys can cause brown spots in the lawn in August, so be sure to apply a general surface insecticide now, as well as a Merit-based grub preventative. If you do that, you should be fine!