The external parasitoidEuplectrus platyhypenaeHoward was reared from 4 species of lepidopterous larvae:Spodoptera frugiperda(Smith),Spodoptera ornithogalli(Guenée),Heliothis zea(Boddie), andTrichoplusia ni(Hübner). These larvae were collected from peanut fields in Caddo County, Oklahoma. No distinct host preference could be established in this study. In the laboratory (temp 22±3°C) a period of approximately 5 days was required for completion of larval development and an average pupal stadium of 10 days was recorded. Parasitism invariably resulted in death of the host within a day of parasitoid pupation.