Biological and social patterns in the Australian bulldog ants of the genus Myrmecia.

Abstract

A method of maintaining laboratory colonies of Myrmecia F. (Hymenoptera: Formicidae) is described and the results of some hundreds of hours of observation reported. Small larvae consumed eggs lying nearby in the egg mass with which they were kept, and thus caused gaps in the size distribution of the brood. The workers separated the larger larvae from the egg mass and fed them on insects. A highly adaptive form of oviposition by workers and queens replaced the regurgitation of many ants, eggs being presented as food to larvae of all sizes or taken by the queen and other workers, sometimes after solicitation. With special exceptions, adult ants or larvae did not consume insects during the winter, though brood cannibalism was prevalent at all seasons. Behaviour patterns of adult ants are described. There was some division of labour (specialization) partly associated with polymorphism, and the social structure appeared more complex than has been supposed. The lack of advanced regurgitation and development of trophic oviposition in Myrmecia is discussed in relation to the evolution of ingluvial feeding in other Formicidae.