none Apanteles papilionis Viereck, preferred the first four larval instars of Papilio demoleus L. for parasitization. The female exhibited arrhenotokous reproduction. The larval development of the parasite was significantly influenced by the larval instars of the host. The duration of parasitic development decreased with increasing host age (instar). The developmental periods of egg, prepupal and pupal stages were not affected by the host age. Different larval instars of P. demoleus had no significant influence on the number of eggs deposited and sex-ratio of the progeny of the parasite.