Submitted to: Journal of Kansas Entomological Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 21, 1999
Publication Date: N/A
Interpretive Summary: The European corn borer is a serious economic pest of maize in the United States and other temperate regions of the world. Because of the limitations of insecticides for control, the development of resistant maize hybrids has been one of the most efficient methods of control. Eleven populations of Peruvian maize were found to have a unique source of leaf-feeding resistance to European corn borer. Our test results indicate that this maize interfered with normal larval development. When resistant freeze-dried whorl leaf material was added to a standard European corn borer diet, the standard diet ingredients either masked the effect of the resistance factor or made up for a nutrient lacking in the Peruvian maize. Further study in this area could help identify the specific factor causing resistance to leaf feeding by European corn borer. The information gained from this research will aid plant breeders in the effective utilization of this maize to develop cultivars resistant to the European corn borer.
Technical Abstract: Eleven accessions of maize from Peru were previously identified as resistant to leaf feeding by European corn borer, Ostrinia nubilalis (Hubner) (Lepidoptera: Crambidae). A study was conducted to determine the mechanism of resistance. The weight of larvae fed Peruvian maize leaf material was not significantly different than of larvae fed a resistant check, CI31A, indicating antibiosis in the Peruvian maize was at a level equivalent to CI31A. The inbred, CI31A, contained high levels of DIMBOA, thus, has strong nonpreference and antibiosis properties towards leaf feeding by European corn borer. The rate of larvae leaving artificially infested Peruvian maize plants over a five-day period was significantly less than CI31A, but, significantly more than a susceptible check, WF9, indicating nonpreference was a possible mechanism of resistance in the Peruvian maize but at a level lower than CI31A. When Peruvian maize leaf whorl material was added to a standard European corn borer rearing diet, the effects of the resistance factor were lost. The standard diet ingredients may have masked the effect of the resistance factor. Another possibility may be that the resistance factor was a deficiency of a vital nutrient needed for normal European corn borer development. This nutrient may have been supplied to the insect when the standard diet ingredients were added to the Peruvian maize leaf material. Further study in this area is needed to identify the basis of resistance.