Phylogenetic analysis and taxonomic revision of the Neotropical genus Argentinomyia Lynch Arribálzaga, 1891 (Diptera: Syrphidae: Syrphinae): Preliminary results

Argentinomyia Lynch Arribálzaga, 1891 is endemic to the Neotropics, with 31 species. The genus is member of Bacchini with Melanostoma and Xanthandrus as sister-group clade (Mengual et al., 2008). Argentinomyia was erected by Lynch Arribálzaga (1891) to accommodate A. testaceipes, a species with elongate antenna. Following Lynch Arribálzaga's (1891-1892) publications, and due to the lack of precise definition, many species were erroneously described in Melanostoma Schiner, Rhysops Williston, Braziliana Curran and Allograptina Enderlein. In the most outstanding works of Argentinomyia, Fluke (1945) divided in two species groups: Melanostoma (short antenna and face without transversal grooves) and Rhysops (long antenna and face with transversal grooves). Despite available taxonomic studies of species groups, Argentinomyia is notable for its lack of internal taxonomic resolution. The phylogenetic relationships of Argentinomyia are reconstructed based on adult morphology. Outgroup taxa include 17 species (7 Bacchini genera). Trichopsomyia antillensis Thompson is selected to root the phylogeny. The initial analysis of 75 phylogenetically informative characters has produced a strict consensus tree that confirms the monophyly Argentinomyia. Important synapomorphies for the genus species thus far are: 1) a bare area under the antenna; 2) long scape; 3) pollinose pattern in female front; 4) face with transversal grooves. The species group: Melanostoma and Braziliana are monophyletic, while Rhysops was recover as paraphyletic. We here present new diagnosis and tentative phylogeny for the genus and related taxa. A new identification key, distribution maps, illustrations of critical characters and male genitalia are provided. Descriptions and redescriptions of the species are also given.