Substrate-transmitted acoustic signals of the primitive cicada, Tettigarcta crinita Distant (Hemiptera Cicadoidea, Tettigarctidae)

Male cicadas are familiar for their unique loud airborne calls used in cour tship and mate recognition. Extant Tettigarcta species in Australia are lit tle-known relict survivors of a primitive Mesozoic cicada radiation which d o not make loud calls and lack either the apparatus to produce them or the auditory organs to detect them. Field studies on live insects in New South Wales for the first time show that Tettigarcta produce low-intensity, subst rate-transmitted acoustic signals in courtship. This habit seems to be a pr imitive (plesiomorphic) feature.