Two new species of Costatrichia ( Trichoptera : Hydroptilidae : Leucotrichiinae )

Costatrichia Mosely, 1937 is a Neotropical genus included in the subfamily Leucotrichiinae. Previously, this genus included 14 described species, two from Brazil and eight from Costa Rica. Based on recent specimens collected with light traps in the Brazilian Amazon and Costa Rica, we describe two new species: Costatrichia ipixuna sp. nov. from the state of Amazonas, Brazil (C. lodora group) and C. falsa sp. nov. from Puntarenas, Costa Rica (C. simplex group). Costatrichia ipixuna sp. nov. is most similar to C. noite Angrisano, 1995, but can be distinguished by the shallower Ushaped incision on posterior margin of sternum VIII, by the absence of the lateral projection of the same segment bearing very long setae, and by the phallus with a pair of spine-like sclerotized processes apically. Costatrichia falsa sp. nov. is most similar to C. zopilote Harris & Holzenthal, 1999, but differs from it by the median pair of spines of segment VIII, directed mesad and curved posteriorly crossing over each other; by the irregular posterior margin of segment VIII, in ventral view; by the segment X without short lateral paired spines; and by the flange-like apical processes on phallus. In addition, we provide the first record of C. noite Angrisano, 1995 from Brazil (state of Amazonas).

Leucotrichiinae was erected by FLINT (1970) to include a distinctive group of exclusively New World microcaddisflies.MARSHALL (1979) proposed a robust classification in her revision of the Hydroptilidae genera and treated the leucotrichiines as a tribe of Hydroptilinae.The group was treated again as a subfamily, when MALICKY (2001) ranked the Ptilocolepidae, a Hydroptilidae subfamily in MARSHALL's (1979) classification, as a caddisfly family.
In a complicated taxonomic history, several genera were described in Leucotrichiinae; of those, some were later removed and then subsequently reassigned to it (FLINT 1970, HOLZENTHAL & HARRIS 1992, HARRIS & HOLZENTHAL 1993, 1994, BOWLES et al. 1999).Presently, the group comprises 189 species in 17 genera, most of which are poorly defined (FLINT 1992, MARSHALL 1979) and some probably represent synonyms.Therefore, a rigorous phylogenetic study is needed to reassess the status of each genus of Leucotrichiinae.
Costatrichia Mosely includes 14 species recorded from Mexico, Central, and South America.The genus was revised by HOLZENTHAL & HARRIS (1999), who described most of the known species.It is divided into three species groups based on the presence of antennal and wing modifications in males and on the male genital structures (FLINT 1970, HOLZENTHAL & HARRIS 1999).Recently, species of the genus were recorded from Bra-zil, with one species occurring in the northern and another in the southeastern regions (SANTOS & NESSIMIAN 2010).Since then, specimens collected in Brazil and Costa Rica revealed two additional new species, and also the first record of Costatrichia noite Angrisano, 1995 from Brazil.

MATERIAL AND METHODS
Specimens were collected with light traps and preserved in 95% ethanol.To observe and draw the genital structures, the abdomen was removed and cleared in a solution of heated 10% KOH.Pencil sketches were made under a compound microscope, equipped with a camera lucida, and then used as templates to trace vector graphics in an Adobe Illustrator (v.13.0.0,Adobe Systems Inc.) document.The structural terminology follows MARSHALL (1979) andHOLZENTHAL &HARRIS (1999).The descriptions provided for the new species were made with the DELTA software (DALLWITZ et al. 1999)  Costatrichia ipixuna sp.nov. is most similar to C. noite Angrisano, 1995, but can be distinguished by the shallower Ushaped incision on posterior margin of sternum VIII, by the absence of the lateral projection of the same segment bearing very long setae, and by the phallus with a pair of spine-like sclerotized processes apically.Costatrichia falsa sp.nov. is most similar to C. zopilote Harris & Holzenthal, 1999, but differs from it by the median pair of spines of segment VIII, directed mesad and curved posteriorly crossing over each other; by the irregular posterior margin of segment VIII, in ventral view; by the segment X without short lateral paired spines; and by the flange-like apical processes on phallus.
Etymology.The species is named after the locality where the holotype was collected.Ipixuna means "black water" in the Tupi-guarani language.
Remarks.This new species belongs to the C. lodora Mosely group, due to the modification on the basal articles of the antennae (Fig. 1) and the presence of reflexed costal cell on the forewings.Costatrichia ipixuna sp.nov. is most similar to C. noite, because both species have a pair of very long, slender processes on the posterior margin of sternum VIII and fused inferior appendages forming a ventral plate, broad basally and incised apically (Fig. 2).However, the new species has a shallower U-shaped incision on posterior margin of sternum VIII and lacks the lateral projection of the same segment with very long, stout setae, which is present in C. noite.Additionally, the new species differs in the phallus, which bears a pair of spinelike sclerotized processes apically (Fig. 6).
Ecological notes.Sampling in both localities from where type specimens were collected were at borders of terra firme Amazonian forests with white sheet and mixed mercury vapor lamps.
Etymology.The name of this species refers to its uncertain position in the genus Costatrichia, from the Spanish "falsa".
Remarks.Costatrichia falsa sp.nov. is similar in the structure of male genitalia to C. zopilote Harris & Holzenthal, tentatively placed in the C. simplex Flint group.HARRIS & HOLZENTHAL (1999) mentioned the uncertain position of C. zopilote in this genus because it has features found in another leucotrichiine genus, Acostatrichia Mosely.While a complete reassessment of the genera included in the subfamily is not available, these two species are maintained in Costatrichia, despite the fact that their affinities with the other described species are obscure.This new species, as C. zopilote, has thick and very long spines arising from lateral lobes of segment VIII (Fig. 12) and inferior append- ages fused basally with paired finger-like processes (Fig. 10).However, the new species differs from C. zopilote in the following features: 1) median pair of spines of segment VIII, which are directed mesad and curved posteriorly crossing over each other (Fig. 10); 2) irregular posterior margin of segment VIII, in ventral view (Fig. 10); 3) segment X without short lateral paired spines; and 4) flange-like apical processes on phallus.Ecological notes.Sampling of type specimens were conducted with two UV tubes over a 90% ethanol-filled plastic tray at the river bed.This river was found within the lodge preserved area of tropical lowland forest.
Costatrichia noite Angrisano, 1995 Remarks.ANGRISANO (1995) described this species from one specimen from Uruguay.HOLZENTHAL & HARRIS (1999) recorded C. noite from Peru and provided additional illustrations of the male genitalia.This species is herein recorded from Brazil, state of Amazonas, confirming its wider distribution in South America.

Two new species of Costatrichia (Trichoptera: Hydroptilidae: Leucotrichiinae) Allan Paulo Moreira Santos 1,2 , Daniela Maeda Takiya 1 & Jorge Luiz Nessimian 1
Costatrichia Mosely, 1937 is a Neotropical genus included in the subfamily Leucotrichiinae.Previously, this genus included 14 described species, two from Brazil and eight from Costa Rica.Based on recent specimens collected with light traps in the Brazilian Amazon and Costa Rica, we describe two new species: Costatrichia ipixuna sp.nov.from the state of Amazonas, Brazil (C.lodora group) and C. falsa sp.nov.from Puntarenas, Costa Rica (C.simplex group).
from Brazil (state of Amazonas).