Four new species of Xiphocentron Brauer, 1870 (Trichoptera: Xiphocentronidae) from the Atlantic Forest, southeastern Brazil

. Four new species of Xiphocentron ( Antillotrichia ) Brauer, 1870 from the Atlantic forest are diagnosed, described and illustrated. All of them have a small mesal sclerite and a set of spines, differing in size, density and position, on the inner face of the inferior appendage. Moreover, tergum IX varies mostly in the shape of the posterior margin. Four species are described as new for science. Xiphocentron ( Antillotrichia ) copacabana sp. nov. is distinguished mainly by the projected basoventral margin of the inferior appendage, the spines are clustered in two regions and the quadrate posterior region of tergum IX. Xiphocentron ( Antillotrichia ) maracanan sp. nov is differentiated by the inferior appendage, with a strongly angled apical region of 90º. Xiphocentron ( Antillotrichia ) redentor sp. nov. differs by the inferior appendage, with a linear row of thick spines, and the tergum IX, with a posterior margin forming smoothly rounded lobes. Xiphocentron ( Antillotrichia ) tijuca sp. nov. is diagnosed by the subbasal region of the preanal appendage, which is markedly projected medially, and by the inferior appendage, which is thin subapically, enlarged apically and strongly bent dorsad.


Introduction
The family Xiphocentronidae Ross, 1949, primarily pantropical in distribution, comprises 178 species distributed in seven genera, being especially diverse in Southeast Asia and Central America.The family was erected by Ross (1949), but it was synonymized with Psychomyiidae Walker, 1852 by Edwards (1961), based on larval similarities, and treated as a subfamily of Psychomyiidae for many years.Schmid (1982) re-established the family status of Xiphocentronidae in a worldwide revision of xiphocentronids, based on the distinct male genital characters, in which the segment X is ventrally closed, supporting an extremely elongated tubular phallus (with the phallobase reaching the abdominal sternum V).Additionally, larvae of Xiphocentronidae can be distinguished by a fusion of the tibia and tarsus of each leg (separated in Psychomyiidae) and by the extension of the mesopleuron anteriorly as a lobate process (absent in Psychomyiidae) (Barnard & Dudgeon 1984).Currently, Xiphocentronidae comprises two subfamilies: Proxiphocentroninae Schmid, 1982, including the Oriental genus Proxiphocentron Schmid, 1982 only, which shares many plesiomorphic characters with Psychomyiidae, and Xiphocentroninae Schmid, 1982, grouping all other genera of the family.
The Neotropical fauna comprises 58 species in three genera: Cnodocentron Schmid, 1982, with 12 species from the southwestern USA to northern South America, as well as India and Southeast Asia; the exclusive Neotropical genera Machairocentron Schmid, 1982, with six species from Central America to northern South America, including Central Amazonia; Xiphocentron Brauer, 1870, with 46 extant species and two subspecies widely distributed in the Neotropics (Holzenthal & Calor 2017).
Xiphocentron is the largest genus in the family and includes five subgenera: Glyphocentron Schmid, 1982 (two species), Rhamphocentron Schmid, 1982 (six species), Sphagocentron Schmid, 1982 (two species), Xiphocentron (five species), and Antillotrichia Banks, 1941 (31 species) (Holzenthal & Calor 2017).Adults are small, generally black to dark brown, with pubescent forewings pointed at apex and covered by fine long dark setae, generally with a circular patch of white setae near the nygma.They are not commonly atracted to light traps since they have diurnal activity, which partially explains their scarcity in collections (Flint 1968;Schmid 1982).Larvae are found on rocks in fast-flowing water or, more commonly, on moist rocks at or above the water line (Holzenthal & Calor 2017).The use of Malaise traps placed above flowing streams and hygropteric environments seems to be the most efficient method to capture specimens of xiphocentronid.
The subgenus Antillotrichia is very similar to Ramphocentron.It can be differenciated by three anal veins in the forewing (two in Ramphocentron) and the hindlegs with simple apical spurs (spurs distinctly enlarged in Ramphocentron) (Schmid 1982).In this paper, we describe four new species of Xiphocentron (Antillotrichia) from the Atlantic Forest in the Parque Nacional da Tijuca, a national park in Rio de Janeiro State, southeastern Brazil.

Material and methods
Specimens were collected between 2014 and 2017 in the Parque Nacional da Tijuca, an urban fragment of Atlantic Forest in the city of Rio de Janeiro, southeastern Brazil (Fig. 1), using Pennsylvania light traps (Frost 1957) and Malaise traps (Gressit & Gressit 1962).The specimens were preserved in 96% ethanol.
In order to observe the wing venation, the right wings were removed and observed under a stereo microscope on a black underground.Photographs of the wing venation and the spurs on the hind tibia European Journal of Taxonomy 441: 1-16 (2018) were taken with a Leica Camera (DFC450) coupled to a Leica stereo microscope (M205C) and then digitized with Adobe Illustrator® CS6.To observe the internal structures, we removed the abdomens and cleared the genitalia following the standard methods outlined by Prather (2003) and Blahnik et al. (2007) using 85% lactic acid or a solution of 10% KOH.The prepared genitalia were transferred to microvials with 96% ethanol.They were examined with optical microscopy at a magnification of 100-400.Structures were traced in pencil using a compound microscope (Carl Zeiss, model Axiolab) equipped with a drawing tube and then digitized with Adobe Illustrator® CS6.The morphological terminology for genitalia follows Nielsen (1957) and Schmid (1982).Terminology for wing venation follows the Comstock-Needham system as interpreted for Trichoptera by Mosely & Kimmins (1953).The phallus in Xiphocentron shows very little variation, mostly concerning the degree of enlargement at Fig. 1.Map showing the collecting sites at Parque Nacional da Tijuca (white circles) and distribution of Xiphocentron Brauer, 1870 in Brazil and part of South America (black circles).Species occurring in Brazil are figured in dorsal view (modified from Schmid 1982;Pes et al. 2013;Vilarino & Calor 2015;Rocha et al. 2017).The Atlantic Forest biome is highlighted in green.VILARINO A. et al., New Xiphocentron from Brazil the apex.Hence, the phallus is not depicted in most of the descriptions.Here, we present only the phallus of X. copacabana sp.nov. in full length as an example, for the other species we illustrate only the apex of the phallus.The glandular regions of the abdominal sternum V do not show any variation among the species here described either, so this structure is only depicted for X. copacabana sp.nov.
A distribution map was generated using the open source software QGIS v. 2.8.2. and a satellite photo from Google Earth (Image © 2017 DigitalGlobe, © 2017 Google, Image © 2017 TerraMetrics).
The type specimens were deposited in the Coleção Entomológica Professor José Alfredo Pinheiro Dutra, Departamento de Zoologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil (DZRJ) and Museu de Zoologia, Universidade de São Paulo, São Paulo, Brazil (MZSP) as indicated in the species descriptions.

Diagnosis
The new species resembles X. maiteae in having the basoventral margin of the inferior appendages distinctly projected posterad.However, the new species differs by having a small mesal sclerite and two clusters of small spines on the inner face of the inferior appendages, one on the ventral projection and another subapically.In X. maiteae, the ventral projection has large dentate spines, and does not form these two clusters of small spines.Additionally, the new species has a broader posterior region on tergum IX and the apex of the phallus is not enlarged as in X. maiteae.They also are differentiated by the forewing venation: fork II is sessile in the new species, while it is peciolate in X. maiteae.

Etymology
The specific epithet refers to the beach at Copacabana, one of the most famous beaches in the world and located in the city of Rio de Janeiro.European Journal of Taxonomy 441: 1-16 ( 2018) Description Adult Forewing length 3.2-3.5 mm (n = 2).Overall color (in alcohol) nearly uniformly medium brown.Tibial spur formula 2-4-3.Hind tibia apical spurs not modified (Fig. 2A).Forewings covered with fine, short, brown setae, with opaque region on anterior margin between Sc and R1 veins.Wing venation (Fig. 2B).Forewings: forks II and IV present; Sc reaching costa; fork II sessile starting in the discoidal cell; thyridial cell opened; fake vein present between M and Cu1a+b; two anal veins are present.Hind wings: forks II and V present; fake veins present; Rs with three branches R2+3, R4 and R5; R1 absent.Abdominal sternum V bearing a pair of mammiform glandular regions (Fig. 2C).
Preanal appendages elongated, about twice as long as segment X, setose; in lateral view (Fig. 3A), basally directed posterodorsally, slightly narrowed and bent posterad at mid-length, apex rounded; in dorsal view (Fig. 3B), enlarged at mid-length, apex slightly crenulated.Inferior appendages with articles completely fused (Fig. 3F); basal region, in lateral view (Fig. 3A), broad, ventral margin distinctly produced; apical region as long as the basal region, slender; in dorsal view (Fig. 3B), apex slightly inflated; inner face with sparse spines on the basal region, and cluster of small spines on projected posteroventral margin and subapically on apical region; mesal sclerite small, slightly larger than sparse spines of basal region.
Phallus tubular, long and slender, in lateral view (Fig. 3D), apex about twice as broad as the base; in dorsal view (Fig. 3E), apex not enlarged, semi-membranous.

Diagnosis
The new species is characterized by a strongly bent inferior appendage (at an angle of about 90° between the base and the apex), with a set of small spines, ranging from the mesal sclerite to near the apex.Moreover, tergum IX has a posterior margin forming a slightly concave central incision with acute sides.
The new species has a similar forewing venation as in X. cobacabana sp.nov., with a sessile fork II.The genitalia of the two species are, however, very different.

Etymology
The specific epithet refers to the soccer stadium Estádio Jornalista Mário Filho, located in the city of Rio de Janeiro, and popularly known as Maracanã.

Description Adult
Forewing length 3.7-4.2mm (n = 2).Overall color (in alcohol) nearly uniformly medium brown.Tibial spur formula 2-4-3.Hind tibia apical spurs not modified (Fig. 4A).Forewings covered with uniformly fine brown setae, with opaque region on anterior margin between Sc and R1 veins.Wing venation (Fig. 4B).Forewings: forks II and IV present; Sc reaches costa and then curves meeting R1; fork II VILARINO A. et al., New Xiphocentron from Brazil sessile starting in discoidal cell; thyridial cell closed; two anal veins present.Hind wings: forks II and V present; Rs with three branches R2+3, R4 and R5; R1 absent.Abdominal sternum V bearing pair of mammiform glandular regions.
Preanal appendages elongated, about 1.5 × as long as segment X, setose; in lateral view (Fig. 5A), basally directed posterodorsally, then bent posterad near mid-length, enlarged and rounded apically; in dorsal view (Fig. 5B), slightly enlarged basally, slightly tapered apically, apex obtuse.Inferior appendages with articles completely fused; basal region, in lateral view (Fig. 5A), broad, bent 90° with respect to apical region, posteroventral margin not produced; apical region as long as basal region, slender, in dorsal view (Fig. 5B), with apex slightly enlarged; inner face with spines ranging from mesal sclerite until apical region; in lateral view (Fig. 5A), spines in a row on ventral margin of apical region; mesal sclerite small, with basal spine (only clearly visible in ventral view).

Diagnosis
The wing venation of the new species is similar to that of X. tijuca sp.nov., having a peciolate fork II, with the nygma outside the fork.They differ, however, in the morphology of the genitalia.In X. redentor sp.nov., the inferior appendages have a linear row of broad spines, ranging from the basal region to subapically, while in X. tijuca sp.nov.they have only four spines mesally below the mesal sclerite.The preanal appendages are straight subbasaly and not produced as in X. tijuca sp.nov.Moreover, tergum IX in the new species has a produced posterior margin, forming rounded lobes, while in X. tijuca sp.nov. the lobes are very shallow.

Etymology
The specific epithet refers to the Cristo Redentor, an Art Deco statue of Jesus Christ, located at the peak of Corcovado in the Tijuca National Park, overlooking the city of Rio de Janeiro.The statue is listed as one of the New Seven Wonders of the World.
Preanal appendages elongated, about twice as long as segment X and setose; in lateral view (Fig. 7A), basally directed posterodorsally, then bent posterad, constricted at mid-length, apex rounded; in dorsal view (Fig. 7B), narrower at base and sinuous, enlarged subapically, apex rounded, slightly rugous.Inferior appendages with articles completely fused; basal region, in lateral view (Fig. 7A), broad, posteroventral margin crenated, not produced; apical region slightly longer than basal region, slender, in dorsal view (Fig. 7B), with apex strongly enlarged; inner face with row of seven broad spines, ranging from basal region to subapical region; mesal sclerite small, bearing two or three points at apex.Phallus tubular, long and slender; in lateral view (Fig. 7D), apex length about three times as long as base; in dorsal view (Fig. 7E), apex not enlarged, semi-membranous.

Diagnosis
The new species can be differentiated from its congeners by the preanal appendage with a subbasal region markedly produced mesad when observed dorsally.Moreover, in ventral view, the apical region of the inferior appendage is subapically thin, then enlarged apically and bent dorsad.The tergum IX is distinct by the soft and shallow incision on the anterior margin, which is deeper in most of the other species.

Etymology
The specific epithet refers to the Parque Nacional da Tijuca, a tropical rainforest in the city of Rio de Janeiro where the specimens were collected.European Journal of Taxonomy 441: 1-16 (2018) long and slender; in lateral view (Fig. 9D), apex about twice as broad as base; in dorsal view (Fig. 9E), apex not enlarged, semi-membranous.

Discussion
Xiphocentron (Antillotrichia) is the only subgenus of the family occurring in South America, now with 18 species recorded in the region (with species from Argentina, Brazil, Colombia, Guiana and Venezuela).Type series usually contain a low number of specimens, because of the weak attraction to standard light traps, when malaise traps are not used.This aspect probably explains the few known records of the group in Brazil and it can lead to an underestimated diversity.Most of the species of X. (Antillotrichia) and other subgenera of Xiphocentron have a forewing with fork II (R4 and R5) sessile (Schmid 1982), although all the species previously known from the Atlantic Forest Region present this fork petiolate.Xiphocentron copacabana sp.nov.and X. maracanan sp.nov.are the first species recorded in this region having a fork II sessile.Xiphocentron (A.) sclerothrix, the only species from the Brazilian Amazon Basin in the subgenus, is more similar to the other species from the Antilles, having long spines in the inferior appendage and a fork II sessile, as is common.All the species here described have inferior appendages with a very simple mesal sclerite, differing from that in X. kamakan, X. ilionea and X. steffeni, where it is distinctly covered with spines.
Phallus tubular, long and slender, in lateral view (Fig 5D), apex almost as broad as the base; in dorsal view (Fig 5E), apex not enlarged, semi-membranous, cleft apically.