An air-puff stimulus was provided to the stationary cricket by a short puff of nitrogen gas from a plastic nozzle (ø = 15 mm) connected to a pneumatic picopump (PV820, World Precision Instruments, Sarasota FL, USA). For the behavioral experiments using the treadmill system, two air-puff nozzles were arranged in parallel to align their center to the same horizontal plane as the top of the treadmill sphere (Figure 1A ). Nozzle ends were placed at 200 mm from the animal. The velocity of the air puffs was controlled at 1.00 m/s, which was measured at the center of the arena with a 405-V1 thermal anemometer (Testo, Yokohama, Japan), by adjusting the delivery pressure of the picopump. The duration of the air-puff stimulus was 200 ms. By changing the cricket’s body axis relative to the stimulus nozzle, the air puffs were applied to the right or left side of the cerci from one of the air nozzles, which was close to the posterior side of the crickets.
The acoustic stimuli were 15-kHz pure tones, synthesized using RPvdsEx software (Tacker Davis Technologies, Alachua FL, USA), and transduced and attenuated using an RM1 processor (TDT). The sounds were calibrated at an average of 70 dB SPL and delivered by a 1.5-inch (3.81 cm) full-range sealed loudspeaker (MM-SPS2, Sanwa Supply, Okayama, Japan), which was located just above the air-puff nozzles at 200 mm away from the animal (Figure 1A ).
The acoustic stimuli were 15-kHz pure tones, synthesized using RPvdsEx software (Tacker Davis Technologies, Alachua FL, USA), and transduced and attenuated using an RM1 processor (TDT). The sounds were calibrated at an average of 70 dB SPL and delivered by a 1.5-inch (3.81 cm) full-range sealed loudspeaker (MM-SPS2, Sanwa Supply, Okayama, Japan), which was located just above the air-puff nozzles at 200 mm away from the animal (