none Spilosoma obliqua; HYMENOPTERAN-PARASITES; Apanteles jayanagarensis; Parasite biology & biometrics Apanteles jayanagarensis; BIOMETRICS-; Immature stages; GENERAL-MORPHOLOGY; Adult & immature stages; LIFE-CYCLE-AND-DEVELOPMENT; Laboratory study; LEPIDOPTERAN-HOSTS; Spilosoma obliqua; Parasite biology & biometrics Biology and biometry of immature forms of Apanteles jayanagarensis Bhatnagar (Hymenoptera:Braconidae) a parasitoid of Spilosoma obliqua (Wlk.) have been studied under laboratory conditions (25 +- 1 degree C, 55-60% R.H., 12 hr photoperiod). The wasp completes its life cycle within 16 days. Developmental duration was: egg 3 days, 1st instar 3 days, 2nd instar 2 days, 3rd instar 3 days, prepupa 1 day, pupa 4 days. The average length and width of newly laid eggs, 1st instars, 2nd instars, 3rd instars and pupae were 0.112 mm and 0.022 mm, 1.255 mm and 0.20 mm, 2.7 mm and 0.62 mm, 3.02 mm and 0.92 mm and 3.10 mm and 1.20 mm respectively.