(Z)-7-DODECENYL ACETATE: A SUPERNORMAL STIMULUS OF Trichoplusia ni (HÜBNER) [LEPIDOPTERA: NOCTUIDAE] SEX PHEROMONE BEHAVIOR

Abstract

Males discriminate between the single most important individual component of the sex pheromone of the female cabbage looper, Trichoplusia ni (Hübner), (Z)-7-dodecenyl acetate (Z7-12:Ac), and a mixture containing Z7-12:Ac and the other five putative components. The manifestation of discrimination is not an enhancement of captures by the mixture; rather, it is a reduction of captures in a paired trap baited with Z7-12:Ac by itself. Previous experiments showed that either or both of (Z)-7-tetradecenyl acetate (Z7-14:Ac) and (Z)-9-tetradecenyl acetate (Z9-14:Ac) were responsible for this discrimination. This report provides evidence that Z7-14:Ac is more active than Z9-14:Ac, which appears to have no demonstrable effect on behavior. The results are discussed with reference to the behavior that is effected by the above three components, the composition of the native sex pheromone, and whether or not Z7-12:Ac might be a supernormal releaser of behavior.

Keywords:

• Behavior
• Olfaction
• Cabbage looper
• Discrimination
• Perception
• Flight
• Trapping

ACKNOWLEDGMENTS

We thank Jane E. Sharp for her technical assistance; William W. Copeland and Richard B. Furlong for their assistance in setting up and servicing the field traps; and Dr. Victor Chew for his important contribution to the statistical analysis. We especially thank R.R. Heath and B.D. Dueben for preparing the bait mixtures and assuring their quantitative and qualitative characteristics by gas–liquid chromatography. We thank A.J. Grant, J.D. Lopez, and D. Johanowicz for their advice during preparation of the manuscript.