none Immature forms of Cotesia orientalis Chalikar & Nikam, a larval parasitoid of Exelastis atomosa Wals. were studied at laboratory conditions (25 +- 1 degree C, 66-60% R. H.). Newly deposited eggs averaged 0.1667 mm in length and 0.046 mm in width. The length and width of first, second and third instar larvae averaged 0.92 mm and 0.151 mm, 2.60 mm and 0.380 mm, 3.210 mm and 0.482 mm respectively. The mean length and width of the pupae averaged 3.2 mm and 1.00 mm. There exists a significant relationship between larval age and larval body forms (length P lt 0.01, width P lt 0.05).