The northern com rootworm, Diabrotica barberi, is believed to have been indigenous to the northern Com Belt of the United States (Branson & Kryson 1981). It was reported as a new pest of com by C.V. Riley (1880), who claimed farmers had been experiencing losses from the pest since 187 4. The remedies suggested were "rotation of crops, destruction of Ambrosia trifida (ragweed) on which the beetles congregate, and the application of lime and ashes around the young com to ward them off." Within two years, SA. Forbes (1882) published a surprisingly complete description of the insect and its damage in his Annual Report. He concluded that there was a relationship between the severity of attack and the number of years com had been planted in a field. Because the larvae were "scattered and hidden in the soil," Forbes felt they would only be susceptible to local applications of "agents" to the soil, but that this would be impractical except on a very small scale. He felt that "no matter how thickly stocked with eggs the soil may be," there was "no reason to fear injury to any other crop than com" and that "a single season in grass or any small grain is sufficient to destroy those in the ground." Even though technical advances have made it economically feasible to protect corn roots with insecticides, crop rotation has remained our preferred method of control where it fits cropping practices.