The European corn borer, Ostrinia nubilalis (Hübner), is an important insect pest of corn, Zea mays L., crop in Moghan region. In field experiments, the density of eggs and larvae of O.nubilalis and percentage of eggs and larvae parasitisms were studied on four corn hybrids NS704 (commercial cultivar), NS770, NS640 and MV524 (cultivars with high yield). Furthermore, i...