The effects of temperature, body mass and feeding on metabolic rate in the tsetse fly Glossina morsitans centralis

Metabolic rate variation with temperature, body mass, gender and feeding status is documented for Glossina morsitans centralis. Metabolic rate [mean +/- SE; VCO2 = 19.78 +/- 3.11 mu L CO2 h(-1) in males (mean mass = 22.72 +/- 1.41 mg) and 27.34 +/- 3.86 mu L CO2 h(-1) in females (mean mass = 29.28 +/- 1.96 mg) at 24 degrees C in fasted individuals] is strongly influenced by temperature, body mass and feeding status, but not by gender once the effects of body mass have been accounted for. A significant interaction between gender and feeding status is seen, similar to patterns of metabolic rate variation documented in Glossina morsitans morsitans. Synthesis of metabolic rate-temperature relationships in G. m. centralis, G. m. morsitans and Glossina pallidipes indicate that biting frequency as well as mortality risks associated with foraging will probably increase with temperature as a consequence of increasing metabolic demands, although there is little evidence for variation among species at present. Furthermore, metabolic rate-body mass relationships appear to be similarly invariant among these species. These data provide important physiological information for bottom-up modelling of tsetse fly population dynamics.