none Chilo partellus; AGE-; Larval instars, preference by hymenopteran parasites; HYMENOPTERAN-PARASITES; Apanteles, Bracon & Stenobracon; Parasitization dynamics & host age preference; HARYANA-; Hisar; Hymenopteran parasitization dynamics & host age preference Apanteles flavipes; Bracon chinensis; Stenobracon; LEPIDOPTERAN-HOSTS; Chilo partellus; Parasitization dynamics & host age preference; HARYANA-; Hisar; Parasitization dynamics in lepidopteran host & host age preference. The level of parasitisation of Chilo partellus (Swin.) larvae on forage sorghum at Hisar by Apanteles flavipes (Cameron), Bracon chinensis (Szepl.) and Stenobracon sp. varied from 2.0 to 33.2, 0.2 to 4.4 and 0.2 to 2.4 per cent during both 1983 and 1984. The peak activity period of the parasitoids during both the years occurred from third week of August to first week of September. Apanteles flavipes parasitised the host larvae in the second to fifth instar but those in the fourth and fifth instar were preferred the most. Bracon chinensis and Stenobracon sp. parasitised only fourth and fifth instar host larvae.