ACOUSTIC ORIENTATION AND COMMUNICATION IN DESERT TENEBRIONID BEETLES IN SAND DUNES

Acoustic orientation and communication were studied in five species of tenebrionid beetles found in the Namib Desert in Namibia. The thresho lds of their sense of vibration were studied in behavioural experiment s. High sensitivity to substrate sound was found in those species rest ricted to living in sand dunes. Wind blowing over the surface of the s and was found to induce substrate noise perceivable to beetles buried in the sand. One species studied responded to this noise by coming to the surface. Detritus, a major food source, is freed from the sand by wind and concentrated at dune slipfaces. The noise generated by the wi nd is an important signal to the buried beetles that food is available . It is possible for beetles on the surface of the sand to perceive no ises made by buried conspecifics and for buried beetles to perceive ot hers walking on the sand surface.