Submitted to: Recent Research Developments in Agricultural and Food Chemistry
Publication Type: Book / Chapter
Publication Acceptance Date: January 15, 1999
Publication Date: N/A
Interpretive Summary: The European corn borer, Ostrinia nubilalis, is a serious pest of corn because caterpillars damage ears, leaves and shanks. They also tunnel into the stalk, which retards vegetative development, weakens the stalk, and increases ear drop. Mobile adults complicate the problem because they aggregate in weedy action sites within or adjacent to corn fields for sexual activity. After mating females disperse and return to the corn for deposition of eggs. How adult corn borers orient and find appropriate sites for eggs is not clear, although they are attracted to volatile scents from undamaged corn and repelled by volatile aromas from insect-injured plants in the laboratory. Individual components or blends of these chemicals probably are used as cues for host finding by adult corn borers. In laboratory tests the volatile corn scent farnesene is attractive to corn borers for egg laying while the closely related chemical farnesal deters females from depositing eggs. This article reviews the recent research on strategies to find and test natural plant chemicals that may influence egg laying of the European corn borer. A natural aldehyde such as benzaldehyde which gives almond and cherry seeds their flavor and aroma is also present in corn and is a deterrent for corn borer females. The compounds reviewed in this article could be used as a tool to find corn plants with native resistance to the European corn borer. Manipulation of corn chemical signals as described in this review could be incorporated into a environmentally compatible management program for the corn borer, which will decrease our reliance on use of insecticides.
Technical Abstract: This article reviews the recent research on how to find plant compounds that may deter oviposition by the European corn borer. The best oviposition deterrents found so far have a benzene ring with a side chain of one-to-three carbons ending in a terminal aldehyde functional group. The shape and reactivity of the benzene ring is modulated by the addition of methoxy or hydroxy groups, which usually decrease deterrent activity. Benzaldehyde, a common corn product was the compound with the highest deterrent activity. The research approaches described and the compounds reported may be used to find corn plant varieties with natural resistance to the European corn borer. Resistant plants may be incorporated into an integrated management program that suppresses corn borers in an environmentally friendly way.