The development, survival, sex ratio of progeny and the intrinsic rate of increase were compared in laboratory under seven temperatures ranging 13 [degree]C to 35[degree] C between two geographic Diadromus collaris populations, one originated from Hangzhou, Zhejiang and the other from Lishan, Taiwan; China, with the pupae of Plutella xylostella as host throughout the experiment. No adult progeny were produced at 13[degree]C and 35[degree]C in each population. No differences on the development time, adult longevity and number of host pupae parasitized per female were detected under 15[degree]C, 25 [degree]C, 30 [degree]C, 32[degree]C and 33. 5 C between the two populations. However, the survival rates of the larva-adult stage in Hangzhoupopulation were higher than those in Lishan population under 32[degree]C and 33. 5 C, and under the late temperature significantly difference was detected. With the exception at 33. 5 C , sex ratios of progeny in Hangzhou population were si! gnificantly higher than those in Lishan population. The intrinsic rates of increase were also higher in Hangzhou population than those in Lishan population and the differences between the two populations were more obvious at 30[degree]C and 32[degree]C. It was speculated that the difference on survival rate under high temperature regime between the two populations was due to their long term adaptation to local climates, and that the intraspecific variations on survival rate and sex ratio of progeny would be the most valuable biological characteristics to be considered at further studying and using geographic populations of the parasitoid in the hiological control of P. xylostella. BR Life cycle and development. Parasites diseases and disorders. Parasites. Insect parasites. Hosts. Insect hosts. Ecology. Population dynamics. Population structure. Abiotic factors. Physical factors. Land zones. Palaearctic region. Eurasia. Asia. Plutella xylostella (Plutellidae): Host; Diadromus collaris (Ichneumonidae): Parasite. Diadromus collaris: Development, Lepidopteran hosts, Plutella xylostella, Parasite development, sex ratio and population dynamics, temperature response, Population dynamics, Population sex ratio, Survival, Temperature, China; Plutella xylostella: Hymenopteran parasites, Diadromus collaris, Parasite life cycle, temperature effects, Temperature, China. ST Insecta, Lepidoptera, Glossata, Heteroneura, Yponomeutoidea, Plutellidae; Insecta, Hymenoptera, Apocrita, Terebrantia, Ichneumonoidea, Ichneumonidae. Arthropods; Hymenopterans; Insects; Invertebrates; Lepidopterans. none