Corn Root Worms - Diabrotica spp.              Clemson University, USDA Cooperative Extension     Whitney Cranshaw, Colorado State University,                                     Slide Series, www.ipmimages.org                           www.ipmimages.org HOSTS: Corn and related crops. DESCRIPTION: The most common local variety is the Western corn root worm. Larvae are white with brown heads, 1/2 inch long and slender. Adults are 1/4 inch long, yellow/tan with three black stripes. LIFE CYCLE: Adult beetles are present from July through September. There is one generation per year. Larvae hatch in June from eggs laid at the base of host plants the previous fall. CONTROLS: Cultural: Additions of organic matter have been shown to decrease root worm populations through increased egg predation. Do not plant corn in the same place for 2 years. Mechanical: Use floating row covers. REMEMBER to remove the row covers after corn begins to tassel so that good pollination may occur. Botanical: Spray adults with Sabadilla or rotenone. Chemical: A selective insecticide formulation of Cararyl sold under the trade name Adios is a less toxic option insecticide. Unfortunately, Adios is not readily available for home gardeners.
Missoula County Extension Office; Missoula, Montana 59808 - Updated for 2006