Anemotactic response threshold of the Indian meal moth,Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), to its sex pheromone

The effect of different concentrations of the sex pheromone (Z,E)-9,12-tetradecadien-1-ol acetate on the upwind anemotactic behavior of the malePlodia interpunctella (Hübner) was measured at 23 ± 1 ° C and 34 ± 1 ° C. The stimulus-response regression lines were analyzed by a new procedure that accounts both for control responses in the absence of pheromone and also for peak responses below 100% in the presence of concentrations considerably above the normal physiological levels. From the regression line for each temperature, the upwind anemotactic thresholds were calculated to be 1.34 × 10⁶ molecules/cm³ at 23 ° C and 1.65 × 10⁴ molecules/cm³ at 34 ° C, similar to other thresholds reported in the literature. Since departures from the two lines occurred at the highest concentrations tested, near 10⁸ molecules/cm³, the upwind anemotactic behavior may change qualitatively above an altered-behavior threshold that is about two orders of magnitude higher than the upwind anemotactic threshold. The lower response at 23 ° C suggests that cool temperatures inhibit flight in response to pheromonal stimulation.Mention of a commercial or proprietary product in this paper does not constitute an endorsement of that product by the USDA.