Both insects can turn grass brown, but they do not feed in the same place. That difference affects what the damage looks like and how the lawn is treated.
Armyworms Chew the Grass Blades
Fall armyworms are caterpillars that later develop into moths. They feed above the soil and can move through a lawn in large numbers. Affected grass may look closely clipped, ragged, thin, or brown.
Atlanta’s warm summers give these insects a long period in which to become active. Problems are often noticed later in the summer, although activity depends on the weather and movement of adult moths. Fresh sod and actively growing grass also deserve attention. The University of Georgia Cooperative Extension notes that armyworm moths are attracted to young, growing grass, making newly established sod more vulnerable.
Armyworm damage often moves faster than a homeowner expects. Caterpillars can be hard to notice until a larger section of grass has already been eaten. Quick changes in the lawn are worth checking instead of waiting for the next mowing or rainfall.
Grubs Feed Below the Surface
White grubs are young beetles. Several beetle species found in Georgia spend part of their life cycle in the soil, where the larvae feed around turf roots.
Early grub damage can resemble drought stress. Grass fades or turns brown even when the soil is moist. As more roots are lost, the turf may feel soft and pull up more easily than the surrounding lawn.
Wildlife activity can provide another clue. Birds may peck at the grass, while armadillos and other animals may dig into the lawn looking for grubs. Their activity does not confirm the problem on its own, but it gives us another reason to check the soil.
