COEVOLUTION OF MUTUALISM BETWEEN ANTS AND ACACIAS IN CENTRAL AMERICA

Abstract

The purpose of this paper is to discuss the coevolution of one of the more thor- oughly studied mutualistic systems in the New World tropics: the interdependency between the swollen-thorn acacias and their ant inhabitants. This system has recently been described in detail in respect to one species of plant, Acacia cornigera L. (Mimosoideae; Leguminosae), and one species of ant, Pseudomyrmex jerruginea F. Smith (Pseudomyrmecinae; Formici- dae), and shown experimentally to be a case of mutualism (Janzen, 1966a). In this species pair, the ant is dependent upon the acacia for food and domicile, and the acacia is dependent upon the ant for protection from phytophagous insects and neighboring plants. The literature dealing only with the New World tropical acacias (Acacia spp.) and their ants (Pseudomyrmex spp.) has been re-evalu- ated by Janzen (1966a) and will not be discussed further in a review sense.