Circadian rhythm of activity in the tenebrionid beetle Blaps faustii (Coleoptera, Tenebrionidae) from the Kara-Kum Desert (Turkmenistan)

Blaps faustii Seidlitz exhibits a distinct circadian rhythm of activity. Th ere are two maximums of activity coinciding with twilight and dawn time, bu t activity may be also observed during night. This rhythm is kept under con stant darkness and temperature. Changes in illumination during a day serve a time cue and promote shifting a rhythm phase holding the permanent phase angle. Temperature influences on the level of B. faustii activity but only during their active period when temperature does not change the rhythm phas e. The beetles change their response to illumination for a day; in the midd le of day they went to shelters. The circadian rhythm saves the beetles fro m effects of high day temperature and allows them to be active for a long t ime. Due to this adaptation, the beetles are able to be active on the groun d surface from early spring to late autumn under arid conditions of Middle Asian deserts.