Phylogenetic analysis and taxonomic revision of the neotropical genus Argentinomyia Lynch Arribálzaga, 1891 (Diptera: Syrphidae)

Abstract

The genus Argentinomyia Lynch Arribálzaga, 1891 (Syrphidae: Syrphinae: Bacchini), was taxonomically revised and a phylogenic analysis was conducted. The monophyly and internal phylogenetic composition of Argentinomyia and related taxa were reconstructed, based on adults morphologic characters. The ingroup includes 26 available species of Argentinomyia. Fourteen species of Melanostoma, Platycheirus, Tuberculanostoma, Talahua and Xanthandrus (all Bacchini) were used as out-groups. Trichopsomyia antillensis Thompson (Pipizini) was selected to root the phylogeny. The analysis of 70 phylogenetically informative characters produced one most parsimonious cladograms (L=120 steps, CI=65, RI=90) within the in-group topology (A. altissima, (A. rex, (A. browni, (A. bolivariensis))), (A. octomaculata, (A. tropica, A. luculenta)), (A. opaca, A. rugosonasa, ((A. crenulata, A. testaceipes))), (A. nigrans, (A. lineata, (A. neotropica, A. pollinosa))), ((A. currani, A. maculata), (A. praeusta, A. jamaicensis))), (A. catabomba, A. lanei)), (A. scitula, A. columbiana, A. fastigata, A. thiemei, (A. longicornis, A. peruviana)))). Argentinomyia is placed in the tribe Bacchini, subtribe Melanostomatina. According to the strict consensus and preferred character state optimizations, Argentinomyia is a monophyletic group with Melanostoma as the sister genus. There are several synapomorphies for Argentinomyia, although all show reversals in at least a few species: 1) a bare area under the antenna; 2) elongated antenna, with scape much longer than wider, basoflagellomere usually elongated; 3) female front with a pollinose pattern; 4) face with transverse grooves, sometimes broadly punctuate and with iridescent reflections; 5) male genitalia with surstyles generally widened and apically irregular. At least seven well-recognizable species groups are characterized: browni, tropica, crenulata, neotropica, maculata, lanei and longicornis. A new key to all species is provided. New diagnosis, detailed distributional data, notes on the biology of some species, and illustrations of critical characters (photographs and drawings) are included to assist the identification.