In the past, corn rotated annually with soybeans or another non-host crop was not susceptible to WCR larval damage because the adult beetles only laid their eggs in cornfields. Larvae that hatched from eggs laid in the previous cornfield could not survive on soybean roots and would consequently starve to death. Thus, corn-soybean crop rotation was the most reliable and safe method for managing corn rootworm. In 1993, the incidence of WCR larval damage in corn planted after soybeans increased dramatically in east-central Illinois, most likely as a response to prolonged rotation between only corn and soybeans. In 1995 and 1997 the damage caused by WCR to firstyear corn was noted as severe and prevalent in east-central Illinois (Spencer et al., 1998, numerous other reports). Since then, the variant WCR has spread to other parts of the eastern corn belt and researchers have determined that there is a variant strain of WCR that preferentially lays its eggs in soybean in anticipation of corn the following spring during egg hatch (O’Neal et al., 1999).