Olfactory orientation responses by walking femaleIps paraconfusus bark beetles : II. In an anemotaxis assay.

Synthetic pheromone was released from a dispenser stretched across the width of a wind tunnel. Beetles in pheromone-free wind wandered in all directions and did not appear to orient to the wind. A dosage series showed that pheromone decreased the walking rate and deviations from the upwind direction, and it increased the turning rate. The tracks were composed of relatively straight or gently curving sections interspersed with more infrequent, larger course adjustments. Although pheromone clearly affected the average heading of beetles within a treatment, any given individual exposed to pheromone did not necessarily head directly upwind or maintain a fixed absolute angle with respect to the wind direction. The response appeared to be an inaccurate anemotaxis, rather than an anemomenotaxis.