Measured behavioural latency in response to sex-pheromone loss in the large silk moth Antheraea polyphemus

Males of the giant silk moth Antheraea polyphemus Cramer (Lepidoptera: Saturniidae) were video-recorded in a sustained-flight wind tunnel in a constant plume of sex pheromone. The plume was experimentally truncated, and the moths, on losing pheromone stimulus, rapidly changed their behaviour from up-tunnel zig-zag flight to lateral casting flight. The latency of this change was in the range 300-500 ms. Video and computer analysis of flight tracks indicates that these moths effect this switch by increasing their course angle to the wind while decreasing their air speed. Combined with previous physiological and biochemical data concerning pheromone processing within this species, this behavioural study supports the argument that the temporal limit for this behavioural response latency is determined at the level of genetically coded kinetic processes located within the peripheral sensory hairs.