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

The main chemical involved in leaf-feeding resistance to European corn borer, Ostrinia nubilalis (Hubner), in Midwest-adapted maize (Zea mays L.) cultivars has been linked to 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one(DIMBOA). But, 11 accessions of Peruvian maize have been identified as having non-DIMBOA resistance to European corn borer leaf feeding. Methanol extracts of leaf material from the 11 accessions of maize were evaluated in laboratory bioassays to measure differences in mortality, larval or pupal weight, and developmental times. Larvae reared on diets with leaf extracts from accessions PI 503720, PI 503725, PI 503728, and PI 503731 were significantly smaller than larvae reared on controls. These data suggest that a biochemical product responsible for resistance can be extracted from some of the maize accessions.