Wind-tunnel study on attraction inhibitor in maleColeophora laricella Hbn. (Lepidoptera: Coleophoridae).

Modifying effects of (Z)-5-decenyl acetate, an attraction-inhibitor of maleC. laricella, were studied at different levels of the pheromonal behavioral sequence. When blended with the attractant alcohol (Z)-5-decen-1-ol, 0.001% acetate significantly reduced and 1% almost abolished orientation flights followed by landing at the source. By contrast, 1000% of the acetate placed 5 cm apart did not suppress orientation flights to the alcohol source. Differential modifying effects of the acetate in blends vs. separate sources also occurred with respect to orientation flight duration, landing position, close-range behavior at the source, and the rate of unsuccessful orientation attempts. Our findings support the view that, inC. laricella, pheromonal inhibition results from simultaneous (as opposed to intermittent) perception of attractant and inhibitor. The various effects of the inhibitory acetate observed in the wind tunnel compare to results of earlier field observations.