none The braconid parasitoid, Apanteles aristaeus Nixon is an important natural enemy of Cydia leucostoma , a pest of tea in South India. The parasitoid preferred late instar caterpillars for oviposition and in the laboratory, development was completed in 21.36 days. The three years' field study (1985-1987) showed that the maximum percentage of parasitism achieved by A. aristaeus was 17.64. A positive significant correlation was obtained between larval density of C. leucostoma and percentage parasitism.