01923nas a2200217   4500008004100000245005900041210005900100260000900159300001400168490000800182520126500190653003001455653002201485653001201507653001701519653002501536100002001561700001901581700001601600856008901616       1995                        eng d00aUltrasound acoustic startle response in scarab beetles0 aUltrasound acoustic startle response in scarab beetles  cJuly  a2593-25980 v1983 aWe discovered an auditory sense in a night-flying scarab beetle, Euetheola humilis, the first scarab to be shown to hear airborne sounds. In the field, beetles were captured beneath speakers broadcasting ultrasound that simulated bat echolocation pulses. Apparently, the beetles took evasive action from a potential bat predator and flew into the traps. Using another behavioral assay in laboratory studies, the beetles were sensitive to frequencies ranging from 20 to 70kHz at levels between 60 and 70dB SPL. One component of the behavioral response, a head roll, was graded with stimulus intensity, and the number of potentials in electromyographic recordings from muscles involved in the roll increased as stimulus intensity increased. The response latency was about 40ms at threshold, decreasing to about 30ms at 20dB above threshold. The beetle’s short response latency is ideally suited for predator avoidance behavior and the frequency tuning of the response suggests that it could function in evasion from insectivorous bats. The beetle’s acoustic sensitivity is remarkably similar to that of other night- flying insects showing ultrasound-induced startle and it should provide these scarab beetles with a similar advance warning of predation risk.10aacoustic startle response10aEuetheola humilis10ahearing10aScarabaeidae10aultrasound avoidance1 aForrest, T., G.1 aFarris, H., E.1 aHoy, R., R.  uhttps://scarabnet.myspecies.info/ultrasound-acoustic-startle-response-scarab-beetles