The developmental time and fecundity of Lasioseius aegypticus were investigated at 25 and 35°C and 75% R.H. when fed on the astigmatid mites, (Rhizoglyphus echinopus and Acarus siro) and the fungus Aspergillus niger. The incubation period, life cycle, adult longevity and life span and female fecundity of L. aegypticus significantly differed according to the different conditions (diets and temperatures). The longest incubation period was noticed when the females of L. aegypticus fed on R. echinopus at 25ºC (2.2 days); while the shortest period was for male on R. echinopus at 35 ºC (1.57 days). Life cycle was longer when females reared on R. echinopus at 25 ºC, as durated 8.5 days; while the shortest period was for males (62 days) on A. siro at 35ºC. The mean longevity of L. aegypticus female fed on R. ehinopus at 25°C lasted the longest period (17.4 days); while the shortest was 8.18 days on A. niger at 35°C.The female fecundity was affected by diet and temperature, as it was high when mites fed on R. echinopus at 35 and 25°C (24.5 and 22.2 eggs, respectively) and (24.5 & 20.1 eggs on A. siro) and (20.5 & 17.6 eggs) on A. niger, respectively.