Glossina (Diptera: Glossinidae) population growth rates

Abstract

Differences in population growth rates, r, and net reproductive rates, R0, are shown between Glossina palpalis gambiensis Vanderplank, G. palpalis palpalis (R.-D.), G. morsitans morsitans Westw., G. morsitans centralis Machado, G. pallidipes Aust. and G. fuscipes fuscipes Newst. from field-collected data and laboratory colonies. The relationships of these population parameters with temperature are shown as well as the temperature-dependence of T, the cohort generation time. Two rapid methods for estimating r from R0 knowing the mean temperature, and a more accurate rapid method of calculating r direct from the capacity for increase, re, were developed from these data. The stable age-structure, C, calculated from these data was used to show that the laboratory-derived age-specific fecundity, mx, is 22% higher than in the field. The difference is probably due to natural abortion in the field and the better nutritional status of laboratory-reared flies. Deviation from the stable age-structure is shown to be an indication of the sample bias and population equilibrium. The relationships of these parameters to the state of a given population and to optimal timing of control efforts are considered.