Rhyacopsyche escamosa Rocha & Santos & Nessimian 2023, sp. nov.

Rhyacopsyche escamosa sp. nov. Figures 14, 15 Description, male. Head. Wider than long, in dorsal view, frontal margin subtrapezoidal, ocellar setose warts large, subtriangular, posterior setose warts subtriangular with longitudinal length about 2/3 transverse width (Fig. 14A). Antennae each 40-articulated, scape about 3x as long as wide, median flagellomeres each about 1.5x as long as wide and with slender tapered setae scattered over entire flagellomere, apical flagellomere conical (Fig. 14B). Thorax. Metascutellum subpentagonal. Length of each forewing: holotype 3.2; paratypes 3.0– 3.2 mm (n = 2). Wings each tapering to acute apex. Forewings elliptical, each with reflexed costal cell covered with dark brown, tear-drop-shape scales; forks I, II, and III present; jugal lobe present (Figs 14C, 14D). Hind wings tapering from basal 1/3, with fork III present (Fig. 14E). Pregenital abdominal segments. Segments V and VI with no modifications. Segment VII with ventromesal process triangular. Genitalia. Segment IX partially retracted within segment VIII, open dorsally between pair of dorsolateral lobes; in lateral view, anterior and posterior margins round (Fig. 15A); in ventral view, anterior margin widely excavated mesally and V-shaped, posterior margin produced into round process (Fig. 15C). Dorsolateral lobes of segment IX elongate, 2x as long as segment, bearing spiniform setae (Fig. 15A); in dorsal view, deeply divided basally, gradually convergent and almost meeting along median line, apically subtruncate bearing fine setae subapicoventrally (Fig. 15B). Inferior appendages elongate, almost as long as dorsolateral lobes of segment IX and extending beyond them, almost meeting basally, with dorsal spiniform setae apically; in lateral view, apex tapered and upturned, ventral lobe broad basally and produced into acute lobe (Fig. 15A). Preanal appendages absent. Pair of subgenital processes slender, ventrally fused into transverse plate (Fig. 15C); in dorsal view, enclosed by segment X, processes meeting apically along median line (Fig. 15B). Tergum X membranous, apically round (Figs 15A, 15B). Phallus tubular, elongate, slightly broader basally, thin membranous sheath surrounding phallus subapically, ejaculatory duct short, slightly sclerotized, not protruding apically, apical membrane with two small sclerites, two lanceolate processes subapically (Figs 15D, 15E). Remarks. Rhyacopsyche escamosa sp. nov. shares with R. tanylobosa Wasmund &Holzenthal 2007 the extremely long dorsolateral lobes of segment IX and inferior appendages. Additionally, the inferior appendages of both species are broad basally. However, in R. tanylobosa the ventral lobe of each inferior appendage is more acute and elongate than in R. escamosa sp. nov. These species are also distinguished from each other by elements of the phallus: In R. tanylobosa, a long paramere is present, while in R. escamosa sp. nov., a pair of small sclerites is situated in the apical membrane and two lanceolate processes are present subapically. The forewings each have a reflexed costal cell which is shared with R. bunkotala Oláh & Johanson 2011, R. hajtoka Oláh & Johanson 2011, and R. tanylobosa (Wasmund & Holzenthal 2007), but in none of these species were the presence of scales in this cell described. Material examined. Holotype. Peru: Cusco: Quincemil, 3 km E, 13º13’03”S 70º43’40”W, 633 m, Malaise, 20.viii.2012, RR Cavichioli, JA Rafael, APM Santos, DM Takiya leg., male (MUSM). Paratypes. Same data as holotype, 2 males (DZRJ). Etymology. Escamosa is the Spanish adjective for scaly, in reference to the dark brown scales covering the reflexed costal cell of each forewing.Published as part of Rocha, Isabela Cristina, Santos, Allan Paulo Moreira & Nessimian, Jorge Luiz, 2023, Taxonomic diversity of Ochrotrichiinae (Trichoptera: Hydroptilidae) from Peru with the description of ten new species, a new distributional record, and an updated checklist, pp. 301-331 in Zootaxa 5353 (4) on pages 323-326, DOI: 10.11646/zootaxa.5353.4.1, http://zenodo.org/record/843060