Ovlposition and development of the ichneumonid Trathala flavoorbitalis (Cam.) a parasitoid of the brinjal shoot and fruit borer, Leucinodes orbonalis Guen., was investigated. The parasitoid responded to a host larva by inserting its ovipositor (stinging) into the larva, whichever instar (first to fifth) it was. All the first and about 50% of the second instars that were stung and oviposited in, were mutilated and died as a result. Successful parasitization and parasitoid development up to adult emergence occurred in 53% of the third, 57% of the fourth and 41% of the fifth instar host larvae. When given a choice of instars for oviposition, the parasitoid avoided all first instar and most second instar larvae, while third to fifth instars were equally accepted. The total developmental time of the parasitoid was much the same (about 20–24 days) whichever larval instar (second to fifth) was parasitized. The parasitized host at pupation contained different developmental stages of the parasitoid, differing in this respect from most other species of larval-pupal parasitoids.