Preimaginal and Adult Experience Modulates the Thermal Response Behavior of Ants

Colonies of social insects display an amazing degree of flexibility in dealing with long-term and short-term perturbations in their environment. The key organizational element of insect societies is division of labor. Recent literature suggests that interindividual variability in response thresholds plays an important role in the emergence of division of labor among workers (reviewed in [1, 2]). Genetic variation can only partly explain the variability among workers. Here we document the effects of both preimaginal and adult thermal experience on the behavioral differentiation of Camponotus rufipes ant workers. We show that preimaginal temperature (22 degrees C or 32 degrees C during pupal stage) affects temperature-response thresholds and temperature preferences of adult brood-tending workers. We further show that brood-carrying experience gathered as adult during several repeated temperature increases modifies thermal behavior. Experienced workers showed a faster transition from first sensing the temperature stimulus to responding with brood translocation. Developmental plasticity of workers provides a colony with flexibility in dealing with thermal variations and constitutes an important mechanism underlying interindividual variability. Adult thermal experience further fine tunes the behavioral response thresholds and reinforces behavioral differentiation among workers.