Age-related repertoire expansion and division of labor in Pheidole dentata (Hymenoptera: Formicidae): a new perspective on temporal polyethism and behavioral plasticity in ants

From the Arctic to South Africa - one finds them everywhere: Ants. Making up nearly 15% of the entire terrestrial animal biomass, ants are impressive not only in quantitative terms, they also fascinate by their highly organized and complex social system. Their caste system, the division of labor, the origin of altruistic behavior and the complex forms of chemical communication makes them the most interesting group of social organisms and the main subject for sociobiologists. Not least is their ecological importance: Ants are the premier soil turners, channelers of energy and dominatrices of the insect fauna. TOC:The importance of ants.- Classification and origins.- The colony life cycle.- Altruism and the origin of the worker caste.- Colony odor and kin recognition.- Queen numbers and domination.- Communication.- Caste and division of labor.- Social homeostasis and flexibility.- Foraging and territorial strategies.- The organization of species communities.- Symbioses among ant species.- Symbioses with other animals.- Interaction with plants.- The specialized predators.- The army ants.- The fungus growers.- The harvesters.- The weaver ants.- Collecting and culturing ants.- Glossary.- Bibliography.- Index.

Division of labor is one of the most basic and widely studied aspects of colony behavior in social insects. Studies of division of labor are concerned with the integration of individual worker behavior into colony level task organization and with the question of how regulation of division of labor may contribute to colony efficiency. Here we describe and critique the current models concerned with the proximate causes of division of labor in social insects. The models have identified various proximate mechanisms to explain division of labor, based on both internal and external factors. On the basis of these factors, we suggest a classification of the models. We first describe the different types of models and then review the empirical evidence supporting them. The models to date may be considered preliminary and exploratory; they have advanced our understanding by suggesting possible mechanisms for division of labor and by revealing how individual and colony-level behavior may be related. They suggest specific hypotheses that can be tested by experiment and so may lead to the development of more powerful and integrative explanatory models.