Cooperation and conflict in termite societies

Abstract

Termites are social cockroaches that evolved eusociality independently from social Hymenoptera (ants, bees, and wasps). Thus, they are diploid organisms, and this has consequences for the occurrence of conflict in termites. Here, I outline the potential for conflict in termites and summarise studies that tested its actual occurrence. In termites, conflicts over the sex ratio, which are typical for haplodiploid social Hymenoptera, are generally absent. All else equal, in monogamous termite colonies, no genetic conflict exists over one's own reproduction versus helping to raise siblings. Potential for conflict in termites mainly arises due to two main causes: nonmonogamy of colonies and options for colony inheritance by workers. Nonmonogamy occurs when colonies are founded by more than one pair of reproductives (mainly in the species-rich Termitidae with largely sterile workers) or due to fusion of neighbouring colonies (mainly in wood-dwelling termites with totipotent workers). Nonmonogamy of colonies could favour kin-discriminatory behaviour, but, like in social Hymenoptera, evidence for nepotism is rare. Conflict over inheritance of the natal breeding position commonly arises in species with nonsterile workers, which develop into (neotenic) replacement reproductives and inbreed when their king or queen dies. Conflict over inheritance seems to be widespread, yet conflict resolution mechanisms may have evolved, which might include the evolution of worker sterility. Generally, few experimental data exist for termites; more research is required for firm conclusions. Such studies should consider the strong interaction between workers' reproductive potential (which varies from totipotent to sterile), power to control their own caste fate, and ecology.