Metrichia kinkuki Rocha & Santos & Nessimian 2023, sp. nov.

Metrichia kinkuki sp. nov. Figure 5 Description, male. Head. Wider than long, frontal margin convex, ocellar setose warts subtriangular, posterior setose warts transversely ellipsoidal with longitudinal length about 1/3 transverse width. Antennae each 18-articulated, scape about as long as width, median flagellomeres each almost as long as wide and with blunt setae forming basal row, apical flagellomere with digitate apical process. Thorax. Metascutellum subtriangular to trapezoidal. Length of each forewing: holotype 1.8 mm; paratype 1.9 mm (n = 1). Wings strongly tapered from near their bases, acute apically. Forewings each with jugal lobe. Pregenital abdominal segments. Tergum V with rectangular mesal tergite longer than wide, long setae arising from membrane on either side. Pair of membranous, cylindrical internal pouches about half as long as segment V apparently arising between segments V and VI dorsally (Fig. 5A). Tergum VI reduced, much shorter longitudinally than previous or succeeding terga, with its tergite transversely rectangular (Fig. 5A). Pair of tiny, dark, round internal sacs apparently arising between terga VI and VII submesally (Fig. 5A). Segment VII with rectangular mesal tergite more than twice as long as wide (Fig. 5A). Genitalia. Segment VIII shorter ventrally than dorsally (Fig. 5B). Segment IX reduced dorsally, partially retracted within segments VII and VIII, covered with long flattened setae; in lateral view, about 3x as long as tall, tapering anteriorly, posterior margin oblique (Fig. 5B); in ventral view, anterior margin blunt, posterior margin excavated mesally (Fig. 5D). Inferior appendages subtriangular, about 2/3 as long as segment IX, each tapering to acuminate apex, covered with flattened setae; in ventral view, broad basally, small spiniform setae mesally on anterior half (Fig. 5D). Dorsal hooks slightly smaller than inferior appendages but positioned anteriorly; in lateral view, bowed posteroventrad, each with two slender mesal projections, one dorsal and other ventral (Fig. 5B). Preanal appendages short and round, covered apically with setae (Fig. 5B). Subgenital processes absent. Tergum X membranous, truncate, covered dorsally with microsetae (Fig. 5C). Phallus tubular, elongate, basal 1/3 two–four times as broad as apical 2/3, with two curved spines subapically arising at same level; apex slightly sclerotized, folded; internal sclerites absent; ejaculatory duct slightly sclerotized, straight, not protruding apically (Figs 5E, 5F). Remarks. This new species is similar to M. alajuela Bueno-Soria & Holzenthal 2003, from Costa Rica, due to the overall aspect of the inferior appendages, subtriangular in lateral view, and with the phallic spines arising at the same level in the phallus. The appearance of the dorsal hooks of these species is almost identical, except that those of M. alajuela lack ventral projections. Metrichia kinkuki sp. nov. can be easily distinguished from this and other Metrichia species by the abdominal modification, with tergite VI reduced, forming a transversely rectangular plate, and tergite VII as a longitudinally rectangular plate. Material examined. Holotype. Peru: Cusco: Quincemil, 3 km E, 13º13’03”S 70º43’40”W, 633 m, Malaise, 20.viii–01.ix.2012, RR Cavichioli, JA Rafael, APM Santos, DM Takiya leg., male (MUSM). Paratype. Peru: Cusco: Quincemil, 19 km W, Rio Araza, Ponte Saucipata, 13º20’10”S 70º50’57”W, 874 m, Malaise, 23–31.viii.2012, RR Cavichioli, JA Rafael, APM Santos, DM Takiya leg., 1 male (DZRJ). Etymology. Kinkuki is a Quechua adjective meaning compressed or compact, in reference to the reduced tergum VI. The species epithet is not a Latin or latinized word; therefore, it is to be treated as indeclinable and does not need to agree in gender with its generic name.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 310-312, DOI: 10.11646/zootaxa.5353.4.1, http://zenodo.org/record/843060