Two new species and a new distributional record of Alterosa (Trichoptera: Philopotamidae) from southeastern Brazil

. The genus Alterosa Blahnik (2005), with 39 extant species, is endemic to Atlantic Forest areas of southern and southeastern Brazil. Herein, we describe and illustrate two new species from Rio de Janeiro state, southeastern Brazil: Alterosa cornuta sp. nov., easily diagnosed by the horn-like intermediate appendages crossing each other, and A. araras sp. nov., recognized mainly by the extremely developed basodorsal protuberance on tergum X and by the rod-like, mesally curved preanal appendages, with at least 2 stout spine-like setae positioned at mid length and with the apex cupped. Additionally, a new distributional record for Espírito Santo state, southeastern Brazil, is provided for Alterosa falcata Blahnik (2005).

Alterosa was erected by Blahnik (2005) to include two previously described species Dolophilodes (Sortosa) sanctipauli Flint (1971) and Dolophilodes (Sortosa) marinonii Almeida & Duarte (2003) and 20 new species.Since then, several species have been described, almost doubling the number of species in the genus (Jardim & Dumas, 2012;Dumas & Nessimian, 2013;Dumas et al., 2013;Barcelos-Silva et al., 2015).Adults are medium-sized, dark-brown in overall color, and can be recognized by features of male genitalia, such as the phallobase structure, which is tubular basally lacking a basodorsal expansion, common in most philopotamids (Blahnik, 2005).They are usually found in pristine headwaters and rapids of streams or small rivers in Atlantic Forest, but are not common in large rivers (Jardim & Dumas, 2012;Dumas & Nessimian, 2013).Despite the several new species described in the genus in the last few years, the diversity of species is still apparently underestimated.There is also a lack of information about its ecology, distribution and biology, especially about its immature stages, which remain unknown.
In the present paper, two new species of Alterosa are described and illustrated from male specimens collected in Rio de Janeiro state, southeastern Brazil.Also, a new geographic record is provided for Alterosa falcata Blahnik (2005), reported here to Espírito Santo state.

MATERIAL AND METHODS
The specimens were collected near pristine streams in Atlantic Forest areas of two municipalities of Rio de Janeiro state -Petrópolis and Rio Bonito (Fig. 1) using Pennsylvania light trap (Frost, 1957) and Malaise trap (Gressit & Gressit, 1962).The collected material was preserved in 96% ethanol.Length of forewing was measured from base to apex and is presented as a range followed by the number of specimens measured.To better observe and illustrate the genital structures, the abdomen was removed and cleared in a heated solution of 85% acid lactic (Blahnik et al., 2007), being mounted on a temporary slide with glycerin jelly.After that, removed abdomens were stored permanently in micro vials with 96% ethanol, with the rest of the respective body.Pencil sketches of genital structures were illustrated using a Carl Zeiss compound light microscope (model Axiolab) equipped with camera lucida and then scanned and used as templates to trace graphic vectors in the program Adobe Illustrator CS6.The terminology used in the descriptions follows that of Blahnik (2005).The holotypes and paratypes are deposited in Coleção Entomológica Professor José Alfredo Pinheiro Dutra, Departamento de Zoologia, Universidade Federal do Rio de Janeiro (DZRJ), Rio de Janeiro state, Brazil.

Alterosa araras, new species (Figs. 2A-2D)
Diagnosis: Alterosa araras sp.nov.clearly belongs to guapimirim group, as defined by Blahnik (2005), and shares many similarities with A. guapimirim Blahnik (2005) and A. orgaosensis Blahnik (2005).All of them have a similarly developed, bulbously enlarged tergum X, with a basolateral projection; similar preanal appendages with a cupped apex bearing a spine-like seta; and similarly shaped inferior appendages, with second articles much shorter than the first.Etymology: The new species is named araras (a noun in apposition) in allusion to the Reserva Biológica de Araras, a beautiful Atlantic Forest reserve where the types specimens were collected.
Remarks: Alterosa araras sp.nov. is very similar and probably closely related to A. guapimirim and A. orgaosensis.Blahnik (2005)  ble that the two species may eventually prove to be not specifically distinct.We therefore carefully examined and compared A. araras sp.nov.with the holotypes of previous described species, which are deposited in Museu de Zoologia de São Paulo (MZSP), choosing describe it as a new species.The new species can be recognized based on morphology of male genital structure, as discussed above.We think that these species represent a species complex, possibly contemporaneously diverged.However, further studies using analysis of DNA sequence may be useful in determining whether they form a species complex or whether they are a single polymorphic species.
Alterosa cornuta, new species (Figs.3A-3D) Diagnosis: Alterosa cornuta sp.nov. is distinctive within the genus and cannot be easily placed in any of the species groups defined by Blahnik (2005).However, the new species share similarities with A. guapimirim Blahnik (2005) and A. orgaosensis Blahnik (2005), regarding the general structure of the inferior appendages, with first article less than half length of the second.Alterosa cornuta sp.nov. is easily diagnosed by the overall shape of the intermediate appendages with the apical half hornshaped and crossing each other over the apical half of tergum X, with each appendage slightly turned ventrad.Additionally, the inferior appendages each have a row of large spine-like setae on the inner margins that decrease in size to the base, which is also asymmetric on the right and left sides.Also, the endotheca has a tongue-like spinous plate, that differs from all others species of the genus.
Wing venation typical for the genus; forewings with forks I-V present, discoidal and thyridial cells similar in length; hind wings with forks I-III and V present.

Etymology:
The specific epithet of this species comes from the Latin word cornuta (horn), in allusion to the horn-shaped intermediate appendages.

Alterosa falcata Blahnik (2005)
Although most species of the genus Alterosa have fairly restricted distributions in pristine Atlantic Forest streams, A. falcata Blahnik (2005) can be considered one of the few exceptions.Originally described from several locations in Minas Gerais, Rio de Janeiro and São Paulo states (Blahnik, 2005), its distribution was extended to other areas of these states (Dumas et al., 2009;Dumas & Nessimian, 2012).Herein, we record this species for the first time from Espírito Santo state, southeastern Brazil.