Submitted to: Journal of Chemical Ecology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 15, 1997
Publication Date: N/A
Interpretive Summary: Chemical signals used by insects for reproduction and feeding are useful tools for nonpesticidal strategies. Chemical modification of these specific signals has resulted in discovery of alternative molecules which are more stable or have novel effects on behavior. We synthesized chemicals related to sex attractant of the Gypsy moth [(+)-disparlure], measured sensitivity of male and female moths to them, and determined effects of them on the ability of male moths to respond to natural female sex attractant and a volatile plant component. Chemicals we synthesized differed from disparlure in that the oxygen atom was replaced by either a carbon and 2 fluorine atoms, a carbon and 2 chlorine atoms, a carbon and 2 hydrogen atoms, or a nitrogen and hydrogen atom. The preceding order reflects order of decreasing activity as measured by electrophysiological methods. While none of these chemicals modified responses of male moths to (+)-disparlure, both (+)-disparlure and (-)-disparlure unexpectedly modified responses to a volatile plant component. Methodologies used in these studies provide a means for testing activities of potential chemical analogs of disparlure to discover novel, biorational chemicals for survey and control of insect pests.
Reception and adaptation of antennal receptors in response to (+)-disparlure [(+)-D], the sex attractant of the Gypsy moth, Lymantria dispar (Lepidoptera:Lymantriidae), its enantiomer (- )-D, and analogs of the epoxide group of disparlure with other 3-membered rings [(+-)-cyclopropyl (2HC), (+-)-difluoro cyclopropyl (2FC), (+-)-AZ] were investigated using electroantennograms. Antennal receptors of male moths were more responsive (5ug stimulus load) to (+)-D than to (-)-D; while responses to each of the analogs were significantly less and did not differ from each other (P>0.05). Responses of female antennae at this stimulus load to any of the compounds were not significantly different. Among the cyclopropane analogs, the order sensitivity was: 2FC>2CIC>2HC. Post exposure responses to hexyl acetate were adapted by either (+)-D or (-)-D, but not by other odorants. Preliminary field data correlate well with knowledge obtained in our studies and demonstrate the usefulness of such studies. Results indicate that novel approaches to design and synthesis of potential agonists of disparlure receptors are necessary before substantial effects on the activity of disparlure are realized.