A life table approach to modeling annual worker production within colonies of the Florida harvester ant (Pogonomyrmex badius)

Using data from more than 200 colony excavations, we incoporate seasonal development rate, forager lifespan, neighbor density, colony size, maturity, activity period and thermal environment into a model of annual worker production for the Florida harvester ant (Pognomyrmex badius). Like most social insects, aging P. badius workers move through a sequence of labor roles, culminating in foraging. By wire marking age-cohorts in field colonies, we demonstrated that a 5 fold difference in the age at first foraging exists between workers born in summer and autumn. The overlap in workers of each development rate generated a predictable, annual pattern of forager allocation. This pattern was influenced from the top-down by conspecific neighbor density, which influenced forager longevity. Increased forager lifespan supressed the development of younger sisters within colonies and promoted colony growth, while increased death rate did not speed up worker devlopment, leading to labor gaps. Like honeybees, the schedule of birth, death and growth  in P. badius is consistent and well suited for a life table approach.