none Lysiphlebus testaceipes; FECUNDITY-; EGG-NUMBER; DEVELOPMENT-; LONGEVITY-; Temperature relationships; HEMIPTERAN-HOSTS; Aphis gossypii; Parasitoid intrinsic rate of increase in relation to temperature; POPULATION-DYNAMICS; Intrinsic rate of increase in relation to temperature; TEMPERATURE-; Intrinsic rate of increase relationships, hemipteran host Aphis gossypii; HYMENOPTERAN-PARASITES; Lysiphlebus testaceipes; Parasitoid intrinsic rate of increase in relation to temperature Lysiphlebus testaceipes Cresson is one of the candidates for use in a programme for biological control of cotton aphid, Aphis gossypii Glover. Longevity, reproduction, development, and intrinsic rate of increase of L. testaceipes were determined in the laboratory at two different temperatures with cotton aphids as host. The average life-time fecundity of one parasitoid was 128.2 eggs at 20 degree C and 180.0 eggs at 25 degree C. Immature mortality was 9.5 and 29.6% at 20 and 25 degree C respectively. Development from egg to female adult was completed in 12.9 days at 20 degree C and 9.5 days at 25 degree C. The lifespan of the females was very short (2.7 and 2.6 days at 20 and 25 degree C respectively). At 20 degree C the r-m value of L. testaceipes was slightly lower than for cotton aphid. At 25 degree C the r-m values of L. testaceipes and A. gossypii were equal. Lysiphlebus testaceipes might be a suitable natural enemy although r-m values are probably too low to be able to overtake an established aphid population.