none Studies were carried out on response of Cotesia marginiventris (Cresson) to low temperatures viz., 5 and 10 degree C on their survival, fecundity, longevity and sex-ratio. Freshly formed cocoons and one day old mated adults were stored for 5, 10, 15, 20, 25, 30, 35 and 40 days. Mortality in adult females at 5 degree C was 2.3, 18.0, 66.0 and 100 percent and at 10 degree C, 2.0, 13.0, 59.3 and 100 percent for 10, 20, 30, 40 days of storage. Males were more susceptible to low temperature than females. Percent mortality in cocoon stage at 5 degree C and 10 degree C after storage for 10, 20, 30 and 40 days was 17.6, 20.3, 60.6 and 100% and 15.6, 19.3, 51.6 and 81.6%, respectively. Adult longevity and fecundity were reduced significantly after 20 days of storage and longer duration had males preponderance in progeny.