none Enter Temperature-dependent development, longevity and mortality of the aphid parasitoid, Diaeretiella rapae (M'Intosh) (Hymenoptera: Aphidiidae) was studied at four constant temperatures, ranged between 15[degree]C and 30[degree]C, using the cabbage aphid Brevicoryne brassicae (L.) as host. Developmental time decreased with increasing temperature. Mummies' developmental period was shorter (6.9[plus or minus]0.83 days) at 30[degree]C and longest (14.6[plus or minus]0.11 days) at 15[degree]C. Mummy-adult developmental period was shorter (3.7[plus or minus]0.10 days) at 30[degree]C and longest (9.7[plus or minus]0.10 days) at 15[degree]C. The shortest developmental period for egg-adult (10.6[plus or minus]0.13 days) was recorded at 30[degree]C, while the longest (24.3[plus or minus]0.14 days) was at 15[degree]C. The temperature threshold for egg-mummy, mummy-adult and egg-adult developmental periods was 2.33, 4.81 and 3.36[degree]C, respectively. The Sum of Effective Temperatures was 192.3, 90.1 and 277.8 degree-days, for egg-mummy, mummy-adult and egg-adult, respectively. Mortality rate of the parasitoid was affected by temperature. The developmental rate and mortality data indicated that the optimum temperature for D. rapae was (20-25) [degree]C under laboratory conditions. 2014 noneEmail20150320