Oryctophila bonaerensis sp. nov. parasitizing curculionid beetle larvae from Argentina, is described and illustrated. The species is characterized by a prominent genital cone and a short and filiform tail appendage. Female with vulva at midlenght of body, vagina long, S-shaped, monodelphic, opistodelphic. Male with one club-shaped spicule. Genital papillae arranged as follows: one pair of large preanal papillae and three pairs of postanal papillae of various sizes: a pair of medium sized papillae is immediately posterior to the anus, followed by a pair of large papillae, and one pair of small papillae at the base of the caudal appendage.