|Alborn, Hans - CMAVE, GAINESVISLLE, FL|
|Turlings, Theodoor - UNIV. NEUCHATEL|
|Jones, Tappey - DEPT OF CHEMISTRY, VMI|
|Stenhagen, G. - CHALMERS UNIV. TECH.|
|Loughrin, John - UNIV. OF KENTUCKY|
|Tumlinson Iii, James|
Submitted to: Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: March 17, 1997
Publication Date: 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, Gainesville, Florida have isolated and identified a chemical from the oral secretions of the beet armyworm caterpillars that triggers the plant biochemical mechanisms to produce and emit the attractive odors. This chemical has been synthesized by a scientist at the Virginia Military Institute Research Laboratories in cooperation with the USDA scientists. This discovery makes it possible to determine the biochemical enzymes and genetic processes in the plant that are activated by the insect produced chemical. 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: N-[17-hydroxylinolenoyl]-L-glutamine, isolated and identified for the first time from the oral secretions of beet armyworm caterpillars, when applied to damaged tissues of corn seedlings, induces the seedlings to emit volatile compounds which attract natural enemies of the caterpillars. Mechanical damage, without application of this compound, does not trigger the release of the same blend of volatiles. This compound is a key component in a chain of chemical signals and biochemical processes that regulate tritrophic interactions among plants, insect herbivores and natural enemies of the herbivores. Understanding these interactions has important implications for biological control of insect pests of agriculture.