SOCIAL BEHAVIOUR AND ITS RELATIONSHIP TO FIELD DISTRIBUTION IN PANESTHIA CRIBRATA SAUSSURE (BLATTODEA: BLABERIDAE)

Abstract Field distribution and laboratory investigations of the social behaviour of an Australian wood cockroach, Panesthia cribrata , are reported. These cockroaches are found in aggregations, most commonly containing a number of adult females, a single male and nymphs of various sizes. Agonistic behaviour is mainly restricted to adult males. This fighting does not lead to the development of hierarchies or defined territories, but results in the dispersal of adult males. Courtship is simple, the female being relatively passive and the male repeating a number of characteristic behavioural acts. P. cribrata evince many of the behaviours observed in other Blaberidae, but adaptation to its restrictive habitat may have resulted in the loss of some of the more intricate behavioural patterns and interactions present in these species. Similarities in the behaviour of P. cribrata and the primitive Cryptocercus punctulatus are probably due to both species inhabiting the same kind of environment and thus are examples of convergent evolution.