Circadian Rhythm in the Tropical AntEctatomma (Hymenoptera: Formicidae)

In early 1960 1 surveyed the daily activity rhythms of three tropical ponerine ants, Paraponera clavata, Ectatomma tuberculatum, and E. ruidum, first on Barro Colorado Island (BCI), Panama, then in the laboratory upon return home. The study of Paraponera was reported previously (McCluskey & Brown 1972). That of Ectatomma presented here is of interest in spite of being based on limited material, because it is one of the few studies of rhythmicity of ants in controlled conditions; the two species appeared opposite in time-ofday out of the nest, in both field and laboratory; and the rhythm of E. tuberculatum persisted in constant conditions.