02271nas a2200241 4500008004100000022001400041245009000055210006900145260001600214300001400230490000800244520155100252653001401803653002401817653001401841653001901855653001401874100002101888700002001909700002301929700002601952856005101978 2000 eng d a0952-836900aA comparative study of ultrasound-triggered behaviour in tiger beetles (Cicindelidae)0 acomparative study of ultrasoundtriggered behaviour in tiger beet cJan-07-2000 a355 - 3680 v2513 a

This study examines the behavioural responses to ultrasound in 52 species from the family Cicindelidae using both tethered Øight and non-Øight assays. Tethered Øying tiger beetles respond to trains of bat-like ultrasonic pulses with a short-latency, multi-component behaviour. There was no variation in the nature of the behavioural responses regardless of geographical distribution or phylogenetic position. Lowest mean behavioural thresholds lie predominantly between 30 and 45 kHz. Sensitivity, however, varies widely, and several species do not respond at all in these assays. The lowest thresholds for responders are most often between 70 and 80 dB SPL. Almost all subgenera of North American tiger beetles in the genus Cicindela have at least some species with low-threshold acoustic behaviour. The single exception is the large subgenus Cicindela where all species are completely unresponsive or have very high thresholds. There was little relationship between habitat and responsiveness to ultrasound, but there is a strong correlation with seasonal activity ± species with adults active in the spring and autumn (all in the subgenus Cicindela )do not show ultrasound-triggered behaviour whereas summer-active species generally do. Superimposing these data on a current phylogeny of the North American tiger beetles suggests that acoustic behaviour (and hearing) is a shared primitive trait among the taxa examined here and that there have been at least Æve independent losses of this character.

10aCicindela10adefensive behaviour10aevolution10ainsect hearing10aphylogeny1 aYager, David, D.1 aCook, Aaron, P.1 aPearson, David, L.1 aSpangler, Hayward, G. uhttp://www.blackwell-synergy.com/toc/jzo/251/3