How to Identify Grubs in the Soil in Florida

Physical Identification

• Carefully turn some garden soil over with a hand trowel or slightly roll a turf edge away from the ground to locate grubs. They are commonly found in the first few inches of soil for ample root access and prolific feeding. Most grub species are white and curled into a C-shape between 1/2 and 1-1/2 inches long. Six legs surround the grub's head as it propels itself through the soil. If you find one or two grubs in one square foot, your infestation does not call for extreme controls. Larger populations may reproduce quickly, however, and they start to damage your garden plants or lawn.

Animal Activity

• Florida has a wide variety of wildlife that feeds on grubs. Birds, moles, raccoons, skunks, armadillos and parasitic wasps look for large grub infestations to feed on near the soil surface. Observe your garden or turf over several days or weeks. Consistent wildlife visiting a specific area gives you an indication of where to look for grubs. Wait until animals or birds leave the area before inspecting the site for grubs. Animal activity may actually alleviate your grub problem if the infestation is relatively small.

Damage

• Grubs typically feed on grass because of its dense root structure. Identifying grubs in your grass often requires damage observation. During the summer, grubs feed almost continuously. Patches of dead or yellow grass appear and spread outward like a water puddle. Walking on grub-infested grass often feels spongy. Grass is slowly losing its root system, causing reduced nutrients and moisture to the blades above. As cool weather sets in, grub activity subsides until spring. Inspect these damaged areas for grubs during active feeding periods. Widespread damage may require controls to stop grass decline.

Control

• Your best control for these pests is proper garden maintenance, especially for grass. Water your grass deeply and infrequently to encourage deep roots. Strong plants withstand grub infestations better and may recover without harmful chemical applications. Allow parasitic wasps to leave their larvae in your soil. They actively feed on beetle larvae, but not your plant roots. Once wasp larvae have fed enough, they pupate and eventually leave your garden.