New species of Tanytarsus van der Wulp (Diptera: Chironomidae) from São Paulo state, Brazil

Tanytarsus van der Wulp, with 355 currently known valid species, is a comparatively large genus of nonbiting midges (Diptera: Chironomidae). Relationships among Tanytarsus and associated genera and among species in the genus have been exceptionally difficult to resolve using morphology or single gene genealogies. Here, the phylogeny of Tanytarsus sensu lato is reconstructed based on the combined analysis of five nuclear markers, including both ribosomal (18S) and protein‐coding (AATS1, CAD, PGD and TPI) genes. Our results indicate that Tanytarsus is paraphyletic with Caladomyia Säwedal placed among South American Tanytarsus, Virgatanytarsus Pinder as part of a Gondwanan clade, and Corynocera Zetterstedt within the Tanytarsus norvegicus (Kieffer) species group. Based on these results, we synonymize Caladomyia and Virgatanytarsus with Tanytarsus. We propose retaining the older name Corynocera until an eventual International Code of Zoological Nomenclature ruling on precedence can be made regarding the more frequent usage of the younger name Tanytarsus. As expected, the previously synonymized Nimbocera Reiss is confirmed to be a junior synonym of Tanytarsus with T. rhabdomantis (Trivinho‐Strixino & Strixino) grouping with other Neotropical Tanytarsus. The genus Sublettea Roback remains valid outside of Tanytarsus + Cladotanytarsus Kieffer. The monophyly of some established species groups is well supported, while other groups are refuted or remain uncertain. Based on a calibrated molecular divergence time analysis, Tanytarsus diverged from its sister group Cladotanytarsus during the Late Cretaceous to Early Paleogene (61–79 Ma). The genus most likely originated in the Oriental and Palearctic regions.

We present data on Chironomidae (Insecta: Diptera) collected in South America together with results on the mitochondrial DNA diversity within selected megadiverse genera. This work is part of an ongoing project on the ancient origin of South American biodiversity using non-biting midges. Collections were made at 42 localities, in March 2014 and February 2015, in a diverse array of habitats, including small streams, rivers, ponds, lakes and bays. In total, 3196 representatives of six subfamilies were collected. Sixty-one genera were identified, containing at least 211 species. The subfamilies Chironominae and Orthocladiinae predominated in all samples. Tanypodinae were often present, but rarely in large numbers. Except for Podonomus pepinellii, reported from Brazil, Podonominae were collected in a few localities in Argentina (Arroyo Lopez, and Arroyo Gutierrez and Gutierrez Lake) and Chile (Llanquihue Lake). Prodiamesinae were only recorded in Chile. Analysis of DNA barcode sequences using neighbor-joining estimation supported 66 species within the selected genera. The chironomid fauna of South America includes multiple genera with worldwide distributions, with Australian, Nearctic and Neotropical components.

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