Two new species and updated checklist of Oxyethira Eaton , 1873 ( Trichoptera , Hydroptilidae ) from Brazil

Two new species of Oxyethira Eaton, 1873 are described: Oxyethira cascadanta sp. n. and Oxyethira quadrilobata sp. n. Description and illustrations of the new species are provided based on specimens collected in Parque Nacional da Serra da Canastra, Minas Gerais State, Southeast Brazil. Both species are assigned to the subgenus Loxotrichia but differ from other species mainly in morphology of the subgenital plate, subgenital processes and inferior appendages. Additionally, we provide an updated checklist of the Oxyethira species from Brazil.


INTRODUCTION
The genus Oxyethira, erected by Eaton (1873) for two species previously occupied in Hydroptila Dalman, 1819, is the most diverse genus of Hydroptilidae (Holzenthal andCalor 2017, Morse 2017).These microcaddisflies are included in the subfamily Hydroptilinae, with other 23 genera (Holzenthal et al. 2007), and have been the subject of several works describing new species, especially in the Neotropical Region (Angrisano and Sganga 2009, Santos et al. 2009, Thomson and Holzenthal 2012, Souza and Santos 2017).However, the diversity of Oxyethira is poorly known and several undescribed species are still to be found, not only in unexplored regions but also in localities previously studied (Souza and Santos 2017).
Here we provide descriptions and illustrations of two new species based on specimens collected in Parque Nacional da Serra da Canastra, a protected area in the Cerrado biome, Minas Gerais State, Southeast Brazil.Additionally, we provide an updated checklist of the Oxyethira species from Brazil (Table I).

MATERIALS AND METHODS
The adult specimens were collected with Pennsylvania light traps (Frost 1957) and preserved in 96% ethanol.In order to observe genital structures, male abdomens were diaphanized in a heated KOH 10% solution, then kept in 50% acetic acid for five minutes, washed in distilled water and transferred to 96% ethanol.Genitalia were examined under a compound microscope (Carl Zeiss, Axio Lab) equipped with a camera lucida, and their diagnostic structures drawn in pencil.The sketches were used as templates to trace graphic vectors in ADOBE ILLUSTRATOR (v.16.0.0,Adobe Systems, Inc.).The terminology for morphology follows Kelley (1984).
The specimens examined are deposited in the Coleção Entomológica Professor José Alfredo Pinheiro Dutra, Departamento de Zoologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil (DZRJ).
Etymology.The specific epithet of the new species refers to the Cachoeira Casca D'anta, the largest waterfall of the São Francisco River, where the specimens were collected.

Female and immatures. Unknown.
Taxonomic notes.As in other species of the subgenus Loxotrichia, the new species also has a deep mesal incision in the sternum VIII, as well as having two asymmetrical subgenital processes.Oxyethira quadrilobata sp.n. is very similar to O. cascadanta sp.n. as discussed under that species.However, it can be easily distinguished from all congeners by the distinct inferior appendages, fused basally and divided apically into four lobes, and the elongate and slender subgenital plate directed anterodorsally.
and O. quadrilobata sp.n., but absent in O. azteca.The subtriangular posterior half of the subgenital plate distinguishes O. cascadanta sp.n. from all congeners.