Sex Pheromones of Lepidoptera. XXX. Disruption of Sex Pheromone Communication in Trichoplusia ni as a Possible Means of Mating Control

Looplure (cis</it>-7-dodecenyl acetate), the sex pheromone of the cabbage looper, Trichoplusia ni</it> (Hübner), was released at various rates from evaporators spaced at various separations from one another in the field. Traps baited with virgin females were used to determine whether males could orient to the natural, female-produced pheromone when they were simultaneously exposed to the synthetic pheromone. An assessment of the percent mating of female moths that were tethered in treated and untreated areas indicated that this trapping technique may indicate the actual degree of communication disruption among wild moths in the field. A greater than 80% reduction in trapped males was obtained when looplure was released at rates as low as 0.1 mg/hectare per night. This disruption of male:female communication appeared to be independent of moth population density. Disruption was obtained at lower looplure release rates in a cool, low-wind, coastal environment than in a hot, erratically windy, desert environment.