Generally white with a brown head, a C-shaped body, and three pairs of short legs. True white grubs (Phyllophaga) have two parallel rows of spines on the underside of the last abdominal segment; annual white grubs (Cyclocephala) have no detectable pattern of spines.

Phyllophaga grubs can seriously damage corn by feeding on roots and root hairs. Damaged plants may be stunted or die. Many species of "white grubs" feed on organic matter. Don't confuse them with Phyllophaga.

May and June (statewide)

Dig up several damaged plants and examine roots and surrounding soil for white grubs.

Not available. Post-emergence plant insecticide treatment not effective. If damage is severe, may need to replant.

http://www.unl.edu/entomology/extension/crops/fieldcorn.shtml