Monday, 18 November 2002 - 1:00 PM

This presentation is part of : Student Competition Ten-Minute Papers, Section B. Physiology, Biochemistry, Toxicology and Molecular Biology

Long-lasting adaptation as a possible mechanism for reduced susceptibility to pheromone-based mating disruption

Lukasz Stelinski, James R Miller, and Larry Gut. Michigan State University, Department of Entomology, Center for Integrated Plant Systems, East Lansing, MI

Electroantennogram (EAG) responses of male Chroristoneura rosaceana (Harris) and male Argyrotaenia velutinana (Walker) to the main component of their pheromone blend and traces of its geometric isomer ((Z)11-14:Ac and (E)11-14:Ac, respectively) were recorded before and after continuous pheromone exposure in laboratory and field experiments. Pre-exposure of male C. rosaceana at concentrations of pheromone ranging from 50 to below 4 ng / ml air for durations of 15 and 60 min significantly reduced peripheral sensory responses to these compounds. The EAG responses of C. rosaceana to all tested dosages of pheromonal stimuli were lowered by 55-58 % and made a linear recovery to 70-100 % of the pre-exposure amplitude within 12.5 min at a rate of 3-4 % / min. Exposures of 5 min were insufficient to maximally adapt C. rosaceana; however, exposures of 15 and 60 min reduced sensory responsiveness to the same minimum. In contrast, EAG responses of A. velutinana, after identical pheromone exposure for 5 and 60 min yielded no long-lasting peripheral sensory adaptation as measured by EAGs, even though this species shares the same main pheromone components with C. rosaceana. We postulate that the long-lasting peripheral adaptation observed for C. rosaceana is a mechanism that impedes central nervous system habituation in this species. In contrast, A. velutinana may be more susceptible to central nervous system habituation because it lacks the capacity for minutes-long adaptation. We propose that long-lasting adaptation may be a mechanism explaining some of the variation in efficacy of pheromone-based mating disruption across taxa.

Species 1: Lepidoptera Tortricidae Choristoneura rosaceana (Obliquebanded leafroller)
Species 2: Lepidoptera Tortricidae Argyrotaenia velutinana (Redbanded leafroller)
Keywords: Electroantennogram, cGMP signal transduction pathway

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