Role of Intercropped Red Clover in Inhibiting European Corn Borer (Lepidoptera: Pyralidae) Damage to Corn in Eastern Ontario

Intercropping of corn with clover significantly reduced European corn borer (ECB), Ostrinia nubilalis (Hübner), damage compared with mono cropped corn at the same planting density. Planting clover after corn reduced ECB damage at two experimental sites in 2 consecutive yr. Time of planting of clover intercrop was important. Damage when clover was planted 10 d after corn was significantly lower in both 1984 and 1985. When clover was planted 25 d after corn, damage was significantly lower in 1985 but not 1984. These relationships held with different rates of N fertilizer application (0, 60, and 120 kg/ha). Cost of reducing ECB damage is lower using an intercrop than a synthetic insecticide.