Abstract The influence of rearing temperature on the development rates of two “dump flies” Ophyra aenescens (Wiedemann, 1830) and Ophyra capensis (Wiedemann, 1818) is analysed. The development times of these species are determined. Flies were reared at three constant temperatures (17±1, 24±1 and 30±1 °C) with a photoperiod of 12:12 and at a relativity moisture of 75–95%. The minimum duration for each development stages, from eggs to pupae and from eggs to adult emergence of O. aenescens and O. capensis are reported. The development rate increases in both species as the rearing temperature rises. A temperature-dependent development model is calculated for each species. The larval and total development of these two species can be estimated if the environmental temperature is between 17 and 30 °C. Compared to O. aenescens, O. capensis has a higher threshold of development and a longer larval development time.