White grubs have damaged fall-planted grass pastures in Missouri the past six weeks, according to the University of Missouri's Integrated Pest & Crop Newsletter. University entomologists blame Southern masked chafer or Northern masked chafer grubs with causing the most damage in seedling grass stands. These grub species have one-year life cycles and are often referred to as "annual" white grubs.
It's difficult to control white grubs once they've caused damage. Few insecticides are labeled for the pest in field crops and they're challenging to apply. The damage may continue until the grubs overwinter in the soil.
Contact Wayne Bailey, University of Missouri extension entomologist, for more information at 573-882-2838.