European Corn Borer: A Nonpreference Mechanism of Leaf Feeding Resistance and Its Relationship to 1,4-Benzoxazin-3-One Concentration in Dent Corn Tissue12

Abstract

A nonpreference mechanism of resistance, as indicated by larval movement off the host plant, plays an impor tant role in the resistance of dent corn, Zea mays L., to leaf feeding by Ostrinia nubilalis (Hübner). When compared with the other inbred lines, the high level of leaffeeding resistance found in the inbred line, CI31A, can be attributcd to its increased level of non preference. Whorl concentrations of 2-hydroxy-7-methoxy-2H.1, 4-benzoxazin-3 (4H) one (HMBOA) and 2,4-dihydroxy-7-methoxy-2H-I, 4-benzoxazin-3(4H)-one (DIMBOA) were significantly different between inbred lines. The data indicate that DIMBOA is a primary chemical factor in the expression of non preference.