Evaluation of conventional resistance to European corn borer (Lepidoptera : Crambidae) and western corn rootworm (Coleoptera : Chrysomelidae) in experimental maize lines developed from a backcross breeding program

Plant resistance is a promising control method for the two most damaging in sect pests of maize, Zea mays L.: the European corn borer, Ostrinia nubilal is (Hubner), and the western corn rootworm, Diabrotica virgifera virgifera LeConte. Fifteen experimental lines of maize, derived from a backcross bree ding program designed to introgress resistance to European corn borer fi om Peruvian maize into two U.S. Corn Belt adapted inbred lines, were evaluate d for resistance to European corn borer and western corn rootworm. The expe rimental lines were in the second generation of backcrossing. All experimen tal lines were resistant to leaf blade feeding by European corn borer. Thes e lines had low levels of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one, a c hemical commonly associated with leaf blade feeding resistance, indicating that this was not the mechanism of resistance to leaf blade feeding in thes e lines. Eleven experimental lines were resistant to leaf sheath and collar feeding by European corn borer. Useful sources of European corn borer ovip ositional nonpreference and root feeding resistance to western corn rootwor m were not identified. Some of the lines evaluated in this study may provid e useful sources of resistance to both leaf blade and leaf sheath and colla r feeding by European corn borer.