Fig. 1. Experimental set-up. Four moths were placed in a closed box. Pheromone was applied through a 2 mm-diameter hole with a Pasteur pipette containing a piece of filter paper bearing pheromone. The pheromone stimulus was controlled by an electronic stimulator through a three-way solenoid valve, and an LED connected to the electronic stimulator flashed for the duration of the stimulus. The moths' response to pheromone and the LED flash were recorded with a CCD camera.