Corn leaf aphid feeding behavior, injury to seedling maize, and colony development on inbred lines differing in DIMBOA concentrations

Abstract

Com leaf aphid rRhopalosiphum maidis (Fitch)] colonization was evaluated on five inbred maize (Zea mays L.) lines (B37, B73, C103, Mol7, and 41:25045) from emergence to the eight-leaf stage. Concentration of 2,4-dihydroxy-7-methoxyl-l, 4-benzoxazin-3-one (DIMBOA) in these inbreds was analyzed from emergence to anthesis to determine its effect on com leaf aphid colonization. Inbred 41:25043, which was colonized by com leaf aphids as it emerged from the soil, had the highest DIMBOA concentration. Inbreds B73 and B37 were low in DIMBOA and were colonized in the three-and six-leaf stages, respectively. Inbreds C103 and Mol7 also were low in DIMBOA and supported small colonies after the six-and seven-leaf stage, respectively. Contrary to findings of previous studies, DIMBOA does not appear to be the primary factor conditioning resistance to the com leaf aphid in these inbreds.