Leaf extracts from Peruvian maize affect larval feeding and development ofEuropean corn borer (Lepidoptera : Crambidae)

The main chemical involved in leaf-feeding resistance to European corn bore r, Ostrinia nubilalis (Hubner), in Midwest-adapted maize (Zea mays L.) cult ivars has been linked to 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMB OA). But, 11 accessions of Peruvian maize have been identified as having no n-DIMBOA resistance to European corn borer leaf feeding. Methanol extracts of leaf material from the 11 accessions of maize were evaluated in laborato ry bioassays to measure differences in mortality, larval or pupal weight, a nd developmental times. Larvae reared on diets with leaf extracts from acce ssions PI 503720, PI 503725, PI 503728, and PI 503731 were significantly sm aller than larvae reared on controls. These data suggest that a biochemical product responsible for resistance can be extracted from some of the maize accessions.