Plasticity in flight muscle development and honey bee division of labor

The goal of this research is to study short- and long-term changes in flight and foraging behavior, in relation to age, genetic, environment, neurochemical changes and contractile protein changes.;For short-term regulation, I examined influence of octopamine on both flight performance and foraging preference of older workers. In the laboratory, octopamine treatment lead to higher wing beat frequency. In the field, in one of two colonies octopamine treatment lead to heavier forage load. Octopamine treatment also changed preference of workers, made them more likely to forage for water or liquids dilute in sugar (3 of 3 colonies). This is consistent with increased sensitivity to sucrose in octopamine treated workers.;For onset of flight, I demonstrated that central colony temperature is important for development of both flight ability and flight muscles of workers. Workers developed the best flight ability when reared at 35°C. Both the structural (Z-175, tropomodulin) and regulatory (troponin-T) contractile proteins of the flight muscles were different in flying and flightless bees.;For foraging behavior, I tested the hypothesis that flight muscle development depends on age and behavior, such that there are differences in precocious and typical foragers. I measured nectar load and contractile protein profile of typical and precocious foragers. Precocious foragers collected less food under field conditions, in comparison to experienced foragers (3 of 3 colonies). There are age-related differences in indirect flight muscle contractile proteins that could explain the age effect on foraging performance. For example a protein at 45 kd size range is different in precocious foragers in comparison to typical foragers.;I also examined genetic effects on flight muscle development. I compared behavior and contractile protein expression in cross fostered Africanized and European honey bees at different ages and development stages. My results show that in European colonies European bees started foraging at younger ages than Africanized bees (4 of 4 colonies). These results suggest colony environment influences behavioral development. I did not find protein differences between Africanized and European bees at similar ages. There are age effects on muscle protein expression profiles of workers of both races.