Separation aggression: A captive study on two Indian ant species, Camponotus compressus (Fabricius 1787) and Tetraponera rufonigra (Jerdon 1851) (Hymenoptera: Formicidae)

Abstract

We studied the aggression reaction of two Indian ant species, Camponotus compressus and Tetraponera rufonigra, using both the species either as a resident and/or intruders to each other and to conspecifics in the ant box to observe whether or not they were showing the reaction towards conspecific and interspecific in the captivity at different time points of isolation from the parental colony. The study revealed a strong and positive correlation between the degree of aggression and the duration of remaining in isolation from the parental colony. A shorter aggression time was recorded during the short period of separation but with more time of isolation, the aggression time increased to a great extent. With time, the ants in the formicarium lost the original body odour, which caused the conspecific to become distant, and aggression followed. Conspecifics of non-parental colonies also exhibited aggression reaction in both the ant species under study, therefore, it can be stated that aggression could not only be due to the body odour dilution, rather there could be an additional factor. The gradual increase in the ambient temperature might play a role. During the change in season from winter to summer the ambient temperature was increasing and the ants were getting active and became more aggressive. We observed a differential aggression in the interspecific reaction and this may be due to the different genetic compositions between them. Keywords: Camponotus, Tetraponera, Ants