Circadian-RIhythms in Male-Ants of Five Diverse Species

When kept at constant temperature and subjected to a daily cycle of light and darkness, males of Paraponera clavata, Iridomyrmex humilis, Solenopsis saevissima, Veromessor andrei, and Camponotus clarithorax were active at different hours. With Solenopsis and Veromessor the active hours relative to the laboratory dawn corresponded with the hours of mating flight in the field. In four of the five species the rise preceding maximum activity began before change to light or to darkness. This endogenous behavior, widespread in males, is of interest because timing in the worker caste has been questioned.