On the identities of Neotropical Stegana species (Diptera, Drosophilidae). II. Stegana acutangula (Hendel) and Stegana triseta (Duda), with descriptions of three new closely related species

Abstract

Stegana (Orthostegana) acutangula (Hendel) from Bolivia and Stegana (Steganina) triseta (Duda) from Costa Rica are redescribed based on type specimens, and their identities clarified. A single syntype male of the first species (type species of the subgenus Orthostegana) is designated as a lectotype and one male out of the four Costa Rican syntypes (3 males, 1 female) of the latter species was selected as a lectotype of the Steganina subgenus. The other three (2 males, 1 female) specimens were designated as paralectotypes. All four males were dissected and their terminalia were photomicrographed. The two male Stegana triseta paralectotypes proved to belong to two unknown species closely related to Stegana acutangula, described here as Stegana dudai sp. nov. and Stegana turrialba sp. nov., and another male specimen, collected at Parque Nacional Yasuní, provinces of Napo/Orellana, Ecuador, is described as Stegana yasuni sp. nov. Additionally, we have included photomicrographs of the habitus of the type specimens as well as of some nontype specimens from Peru and Costa Rica. Based on the descriptions herein we not only clarified the status of these five species but also propose including all of them in the subgenus Orthostegana.