Dd. Yager et Hg. Spangler, BEHAVIORAL-RESPONSE TO ULTRASOUND BY THE TIGER BEETLE CICINDELA-MARUTHA DOW COMBINES AERODYNAMIC CHANGES AND SOUND PRODUCTION, Journal of Experimental Biology, 200(3), 1997, pp. 649-659
Tethered flying tiger beetles, Cicindela marutha, respond to trains of
bat-like ultrasonic pulses with a short-latency, multi-component beha
vior, The head rolls to one side, the metathoracic legs kick to the op
posite side, the elytra swing backwards towards the hindwings and pron
ate, the hindwings increase their stroke excursion and freqency, and t
he plane of the hindwing motion tilts forward, In addition, the beetle
s produce trains of ultrasonic clicks typically containing 100-200 cli
cks in response to a 1 s stimulus, The clicks average 85-90 dB SPL at
2 cm, The latencies for hindwing changes and elytra swing in response
to stimuli more than 10 dB over threshold are 90-110 ms; the latency t
o clicking is 120-150 ms. Neither the head roll nor the leg kick appea
rs to be directionalrelative to the sound source. The behavioral respo
nse is broadly tuned with greatest sensitivity at 30-60 kHz and mean b
ehavioral thresholds of 75-80 dB SPL, Physiological audiograms from th
e auditory afferents show substantially greater sensitivity and sharpe
r tuning than the behavioral response, which suggests that tiger beetl
es may use their hearing in other contexts as well as during flight, T
he combination of aerodynamic components and arctiid-moth-like clickin
g may provide these insects with a powerful defense against attack by
echolocating bats.