Taxonomic revision of the robber-fly genus Leptopteromyia Williston, 1907

     Leptopteromyia (Diptera: Asilidae: Leptogastrinae) is a genus of new world robber flies found as far north as California, USA and as far south as Argentina. They are generally small, elongate flies, rarely exceeding 10 mm in length. It is believed that all species of Leptopteromyia lay their eggs in the silken galleries of webspinners (Insecta: Embioptera). The larvae are predatory and pupate within the nest. This is an unusual reproductive strategy for robber flies, and the host specificity is not known. It is possible that Leptopteromyia has been introduced outside its natural range, with the pupae catching a ride on agricultural or timber products infested with embiopteran nests. The majority of the known specimens (including all type specimens) were borrowed for this revision. There are currently 8 described species of Leptopteromyia: L. gracilis Williston, 1908; L. americana Hardy, 1947; L. lopesi Martin, 1971; L. peruae Martin, 1971; L. brasilae Martin, 1971; L. colombiae Martin, 1971; L. mexicanae Martin, 1971; and L. argentinae Martin, 1972. Using the morphospecies concept, this revision synonymizes L. lopesi with L. gracilis and L. mexicanae with L. americana, and also proposes 11 new species. One fascinating species from Guatemala possesses extremely unique characters, and the delineation of Leptopteromyia will have to be changed to accommodate it. This species is hypothesized to be the sister taxon to all other Leptopteromyia. Throughout this revision particular attention is provided to the morphology of the male terminalia, and illustrations and micrographs of these and other structures are included.