The performance of 4 populations of opaque-2 corn IAC Maya o2, IAC-1 o2, their intervarietal hybrid IAC Phoenyx o2, in relation to the damage of the corn earworm Heliothis zea (Boddie, 1850) (Lepidoptera, Noctuidae), was studied. The double hybrid IAC Hmd 7974 was used as susceptible check. The populations were not subjected to any selection in relation to insects. They were selected only in relation to yield and protein quality. The results indicated a quadratic response of the cycles of selection of the IAC Maya o2, in relation to the corn earworm, and there was a reduction of damage of 3.39% per cycle in the population of IAC-1 o2. The damage grade of cycle 4 was 13.6% lower than the original cycle. The intervarietal hybrid IAC Phoenyx o2, showed similar damage in all cycles. The susceptible check IAC Hmd 7974 was the most damaged treatment in the four locals of observation.