Data from three published studies on the development ofProstephanus truncatus(Horn) reared at constant temperatures and relative humidities (RH) were reanalysed to provide new information and quantitative description needed for predicting developmental times or rates in different environments. Models fitted to the temperature‐dependent development data were used for comparing developmental times among insect stages, relative humidities, diets and studies. Development of the eggs and pupae was similar at 40%, 70%, 80%, and 90% RH. Significant differences were detected between studies in the egg hatch to adult development and larval development, attributable, in part, to differences in the degree of compaction of ground maize used for rearing insects. For all life stages the temperatures for minimum (Tmin) and maximum (Tmax) developmental rates, and degree‐days aboveTminrequired for completion of development, were estimated. The linear degree‐day and nonlinear models presented here could be used for predictingP. truncatusdevelopment in the field. In conjunction with age‐specific fecundity and adult longevity data, these development models will be valuable in predicting population trends ofP. truncatusin the field. Predicting development and population trends is important for accurately timing insect sampling programmes and control tactics.