Accepted by Kai Heller: 12 Dec. 2016; published: 13 Feb. 2017 ZOOTAXA ISSN 1175-5326 (print edition) ISSN 1175-5334 (online edition) Copyright © 2017 Magnolia Press Zootaxa 4231 (3): 327–340 http://www.mapress.com/j/zt/ Article 327 https://doi.org/10.11646/zootaxa.4231.3.2 http://zoobank.org/urn:lsid:zoobank.org:pub:0D9AFF66-93C6-4F7C-B156-D8480F84884A A new species of Euricrium Enderlein from southern Brazil, new records for E. varians (Lane), a new combination, and a key for the Neotropical species of the genus DALTON DE SOUZA AMORIM 1 & GUILHERME SCHNELL E SCHÜHLI 2 1 Departamento de Biologia, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandei- rantes, 3900, 14.040-901, Ribeirão Preto, SP, Brasil. E-mail: dsamorim@usp.br 2 Embrapa Florestas, Estrada da Ribeira, km 111, CP 319, 83.411-000, Colombo, PR, Brasil. E-mail: guilherme.schuhli@embrapa.br Abstract A new species of the genus Euricrium is described—Euricrium edwardsi sp. n.—from the State of Paraná, southern Bra- zil. Additional material of E. varians is identified and illustrated, expanding the known distribution of the species. E. un- imacula (Lane), n.com. is redescribed based on the female holotype and illustrated, and formally transferred to Euricrium. A key for the Neotropical species of Euricrium is presented and comments are made on the known diversity of the genus. Key words: gnats, fungus-gnats, taxonomy Introduction The family Sciaridae fits in the suborder Bibionomorpha (see Diptera classification in Amorim & Yeates 2006) in a clade often named Sciaroidea (e.g., Wood & Borkent 1981) or occasionally Mycetophiliformia (Hennig 1973, Amorim & Rindal 2007). The position assumed for Sciaridae within this group has varied quite a lot between authors. The Sciaridae have been assumed, for example, to be sister group to the clade (Lygistorrhinidae + Mycetophilidae) (Hennig 1954, 1973, Matile 1990, 1997), to (Cecidomyiidae + Rangomarama) (Jaschhof & Didham 2002), to all Sciaroidea but Cecidomyiidae (Amorim & Rindal 2007), to the Mycetophilidae (Hippa & Vilkamaa 2006), and to the Diadocidiidae (Ševčik et al. 2014), among other contrasting topologies. The Sciaridae are presently known from over 2,600 species described in the world, distributed in about 80 genera and 45 subgenera (Menzel, pers. comm.). The actual number of existing species was assumed to be 5,000- 10,000 (Mohrig & Menzel 2009), but recent numbers may suggest a 10-fold higher diversity (Hebert et al. 2016). The fossil record for the Bibionomorpha begins in the upper Triassic with members of the family Bibionidae (Evenhuis 1994), while the Pachyneuridae are known from the upper Jurassic (Evenhuis 1994). The Keroplatidae were also recorded in the upper Jurassic (Evenhuis 1994), while genera of Diadocidiidae, Lygistorrhinidae, Mycetophilidae are known from the early Cretaceous (Blagoderov & Grimaldi 2004). The oldest known Sciaridae members are undescribed species from the Aptian Lebanon Cretaceous amber and Turonian New Jersey amber (Whalley 1981, Grimaldi et al. 1989). Nonetheless, the earliest described fossil species of Sciaridae are from the Cenozoic (Evenhuis 1994, Amorim & Silva 2001). The family is remarkably homogenous morphologically. The genera do not diverge too much from each other in morphology and congeneric species often are similar and pretty hard to distinguish from each other. Sciaridae larvae feed in a large range of resources (Mohrig & Menzel, 2009). Most genera are phytosaprophagous, some species were reported as plant tissue miners (Tuomikoski 1957). The study of the phylogeny of the sciarids shows that the biology of the family evolved from rotten wood to plant litter, with independent developments of attack of plant tissues (Shin et al 2013). Many of the genera of the family are worldwide in distribution, but some genera are endemic to single regions, as is the case of the Euricrium Species of the genus were originally described under the supra-specific names