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ARS Home » Southeast Area » Gainesville, Florida » Center for Medical, Agricultural and Veterinary Entomology » Chemistry Research » Research » Publications at this Location » Publication #98339
Title: IDENTIFICATION AND SYNTHESIS OF VOLICITIN AND RELATED COMPONENTS FROM BEET ARMYWORM ORAL SECRETIONS

Author
item ALBORN, HANS - ENT. DEPT., UNIV. FLORIDA
item JONES, T - VIRGINIA MIL. INSTITUTE
item STENHAGEN, G - CHALMERS UNIV., SWEDEN
item Tumlinson Iii, James

Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: When beet armyworm caterpillars chew on corn or cotton leaves the plants emit an odor that attracts natural enemies of the caterpillar pests. These natural enemies, which parasitize the caterpillars, are effective biological control agents. Domestic varieties of corn and cotton, which have been bred for high grain and fiber production, have much reduced capabilities for production of the odors when compared to wild varieties. Scientists at the Center for Medical, Agricultural and Veterinary Entomology, ARS, USDA, Gainesville, FL, have identified and synthesized several chemicals from the oral secretions of the beet armyworm caterpillars and tested them to determine which ones trigger the plant biochemical mechanisms to produce and emit the attractive odors. Corn seedlings incubated in very low concentrations of two of the synthetic chemicals emit large quantities of odors that attract parasitic wasps that attack beet armyworm caterpillars. This discovery will facilitate the determination of the biochemical enzymes and genetic processes in the plant that are activated by the insect produced chemicals. With this knowledge it should be possible to develop plants that, when attacked by insect pests, become highly attractive to natural enemies of those pests. This will significantly enhance the effectiveness of biological control methods with insect natural enemies.

Technical Abstract: Oral secretion of beet armyworm caterpillars (BAW), when applied to damage tissues of corn seedlings, induces the seedlings to emit volatile compounds which attract the natural enemies of the caterpillars. The key elicitor present in BAW oral secretion is N[17- hydroxylinolenoyl]-(L)-glutamine, (Volicitin). Analysis of the oral secretion showed that it also contained N[17-hydroxylinoleoyl]-(L)- glutamine, free 17-hydroxylinolenic and 17-hydroxylinoleic acid, the glutamine conjugates of linolenic and linoleic acid as well as free linolenic and linoleic acid. Here we present the identification and synthesis of the hydroxy acids and of the glutamine conjugates.