This project is awarded under the Minority Postdoctoral Research Fellowships and Supporting Activities Program for 2006. The nature of castes is central to understanding the organization of work in social insects, yet there is profound disagreement over this fundamental concept. The temporal caste concept posits that insect colonies exhibit a division of labor in which workers specialize on changing task sets as they age. An alternative model, which has gained support in recent years, proposes that colonies are composed of flexible workers able to perform any task as demand necessitates. My previous work showed that honeybee workers are capable of switching between tasks not requiring a physiological specialization, but are incapable of switching to tasks for which such a specialization is required. Accordingly, I proposed a revised caste concept that stresses limited flexibility within a stable caste system. This model has the potential to bridge the divide between those models stressing flexibility in task allocation and those models stressing specialization among workers. The objective of my current research is to determine how broadly applicable this revised caste concept is by testing its relevance for another species of social insect. The stingless bees strongly differ from honeybees in both colony size and habitat. Methods used to elucidate the caste system in honeybees will be tailored to the stingless bee Melipona panamica. Specifically, experiments designed to test for inflexibility in task performance related to physiological specialization and tests of colony flexibility using experimentally generated single-caste colonies will be conducted. This work will shed light on the still poorly understood method by which flexible task allocation occurs within the confines of an inflexible caste system. My career goals are to conduct postdoctoral research before obtaining a position as a professor at a major research university in the United States. This fellowship supports that goal in a number of ways. First, it provides an opportunity to conduct research aimed at cementing the importance of my dissertation work. Second, it provides an opportunity to collaborate with numerous scientists from related fields at the Smithsonian Tropical Research Institute and in particular Dr. William T. Wcislo. This institute, being a center for research on ecology, behavior, and evolution, hosts hundreds of researchers in these fields each year. The large number of researchers in different disciplines in attendance at the institute should allow me to meet researchers with whom I can plan long-term future collaborative studies on social insects using an integrative approach. Third, and finally, this fellowship will allow me to increase my set of basic skills in topics such as multivariable statistics and theoretical modeling, both of which are of increasing importance in behavioral ecology.
