Metrichia quechua, Rocha & Santos & Nessimian, 2023

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, Zootaxa 5353 (4), pp. 301-331 : 316-318

Metrichia quechua sp. nov.

Figures 9 , 10

Description, male. Head. Not completely visible in pharate adult. Antennae each 16-articulated, scape about 3x as long as wide, median flagellomeres each about 2x as long as wide and with blunt setae forming basal row, apical flagellomere with digitate apical process ( Figs 9A, 9B ).

Thorax. Metascutellum subtriangular to trapezoidal ( Fig. 9A ). Length of each forewing: holotype 1.3 mm; paratypes 1.4–1.5 mm (n = 4). Wing venation not completely visible in pharate adult.

Pregenital abdominal segments. Segment IV with pair of large, dark, round internal pouches in dorsoposterior area, about half as long as segment, hachured in appearance; tergite quadrate ( Fig. 10A ). Segment V with pair of membranous internal pouches in posterior area, about 1/3 as long as segment; pair of brushes of very long, curved, decumbent setae dorsolaterally ( Fig. 10A ); in dorsal view, tergite with posterior half narrowing towards apex ( Fig. 10A ). Segment VI with pair of dorsolateral flaps each bearing brush of long, decumbent setae; tergite subrectangular, wider than long ( Fig. 10A ). Segment VII with tergite wider than long, smaller than previous tergites ( Fig. 10A ). Pair of tiny, dark, round internal sacs apparently arising between terga VI and VII submesally ( Fig. 10A ).

Genitalia. Segment VIII shorter ventrally than dorsally ( Fig. 10B ). Segment IX reduced dorsally, partially retracted within segments VII and VIII, covered with long setae ventrally; in lateral view, twice as long as tall, tapering anteriorly to acute anterior margin, posterior margin oblique ( Fig. 10B ); in ventral view, anterior margin round, posterior margin shallowly excavated mesally ( Fig. 10D ). Inferior appendages elongate, almost as long as segment IX, tapering to sharply acuminate apex, covered with long setae; in ventral view, subtrapezoidal, broad basally, with fine spiniform setae mesally on anterior half, incurved in apical half ( Fig. 10D ). Dorsal hooks almost half as long as inferior appendages; in lateral view, bowed posteroventrad and each with small, subtriangular dorsomesal projection ( Fig. 10B ). Preanal appendages short and truncate, covered apically with small setae ( Fig. 10B ). Subgenital processes absent. Tergum X membranous, truncate in dorsal view, covered dorsally with microsetae ( Fig. 10C ). Phallus tubular, elongate, basal half 3x as broad as distal half; two large spines subapically arising from different levels; apex slightly sclerotized, folded; internal sclerites absent; ejaculatory duct slightly sclerotized, undulating, not protruding apically ( Figs 10E, 10F ).

Pupal case. Length 2.5–3.0 mm (n = 5). Made of silk with algal filaments added concentrically, covered with fine sand grains, forming two oval lateral valves; closed dorsally and ventrally, with attachment ligament at ventral corners of anterior and posterior margins when seen dorsally; ends sealed. Pharate adult covered by semipermiable cocoon ( Fig. 9C ).

Remarks. Metrichia quechua sp. nov. is closest in appearance to M. cuspidata Flint 1991 , from Colombia and Mexico, due to the inferior appendages tapering to an acuminate apex and the short, decurved dorsal hooks. However, the inferior appendages of the new species are almost as long as segment IX, but in M. cuspidata they are smaller. In addition to the internal sacs located between segments V and VI, M. quechua sp. nov. also has a pair of large, dark internal pouches in segment IV, which are absent in M. cuspidata .

Material examined. Holotype. Peru: Cusco: Quincemil, 19 km W, Río Araza, Puente Saucipata , 13º20’10”S 70º50’57”W, 874 m, Malaise, 26.viii.2012, RR Cavichioli, JA Rafael, APM Santos, DM Takiya leg., pharate male ( MUSM) . Paratypes. same data as holotype, 2 pharate males ( DZRJ) ; same data as holotype, 2 pharate males ( INPA) .

Etymology. Quechua, also called Quíchua or Quéchua, is an important indigenous language in South America, currently with eight to twelve million speakers spread across Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. In Peru, it is the most widely spoken indigenous language, with the largest number of speakers found in the highland Andean regions. The species epithet is a noun in apposition with unvarying gender.

Figures

FIGURE 9. Metrichia quechua sp. nov. 9A, 9B, pharate adult, habitus: 9A, dorsal; 9B, ventral. 9C, pupal case, right lateral.

FIGURE 10. Metrichia quechua sp. nov. 10A, abdominal segments IV–VII, dorsal. 10B–10F, male genitalia: 10B, left lateral; 10C, dorsal; 10D, ventral; 10E, phallus, dorsal; 10F, phallus, left lateral. Abbreviations: IV = tergum IV; V = tergum V; VI = tergum VI; VII = tergum VII.