ABSTRACT
we come now to a consideration of the social insects which have themselves adopted a life of parasitism in the colonies of other social insects, a subject which has received much attention from a number of investigators during the past quarter of a century. Cases of such social parasitism have been observed among all the groups, wasps, bees, ants and termites, but are most frequent and have been most carefully studied among the ants. The relationships between the social parasites and their hosts are very diverse both in their character and in the degree of their intimacy. A parasite and host which are closely allied structurally and ethologically and represent species of the same genus can obviously enter into much more intimate relationships with one another than distantly related species, or those belonging to different subfamilies or orders. Thus although even colonies of ants and termites may contract relations with one another, they are never very intimate and are due either to predatism on the part of the ants or to mere parœcism, or indifferent toleration. From the viewpoint of evolution it is interesting to note that the numerous cases of social parasitism now known are all sporadic and convergent developments, and if we omit the termites as we shall have to, owing to insufficient knowledge and the limits of our time, and confine our attention to the Aculeates, we shall find that the infestation of their colonies by other Aculeates is in many of its features quite distinct from any other known type of parasitism. The only similar phenomena are the parasitism of human groups and races by other human groups and races, i.e., parasitism existing between societies of the same species, a subject which has not received the attention it deserves by sociologists since attention was called to it many years ago by Massart and Vandervelde (1893). That the erudite Giard was fully aware of the significance of human parasitism is apparent from the fact that he gave the Belgian investigators’ work a prominent place in the journal which he founded, the “Bulletin Scientifique”. 1
