A new genus and species from Ecuador of Physoderinae (Heteroptera: Reduviidae), Leptophysoderes orellana n.gen., n.sp., are described. Leptophysoderes represents one of the two New World genera now known in this group of otherwise Pacific, Indopacific, and Madagascan Reduviidae. The initial diagnosis of Physoderinae was based on the Pacific and Indopacific genus Physoderes Westwood. This diagnosis was not adjusted after the subsequent inclusion of 11 genera from Madagascar and the Neotropical genus Cryptophysoderes Wygodzinsky and Maldonado in Physoderinae. The diagnosis is here modified to characterize a more inclusive Physoderinae, comprising Cryptophysoderes, Leptophysoderes, Physoderes, and the Madagascan genera.