Ochrotrichia sagitta, Cavalcante & Dumas & Nessimian, 2018

Cavalcante, Bruna Maria Silva, Dumas, Leandro Lourenço & Nessimian, Jorge Luiz, 2018, New species and new geographical record of Ochrotrichia Mosely 1934 (Trichoptera: Hydroptilidae) from Rio de Janeiro state, Brazil, Zootaxa 4462 (2), pp. 229-236 : 232

Ochrotrichia sagitta , new species

( Fig. 2A–2D )

Diagnosis. Based on the overall arrangement of elongate inferior appendages and tergum X divided into two conspicuous processes, this species belongs to the O. aldama Group of Flint (1972). Ochrotrichia sagitta sp. nov. resembles O. caatinga , O. ketaga Oláh & Johanson 2011 , O. insularis Mosely 1934 , and O. taunay sp. nov. in the shape of tergum X with a large central process tapering to its apex and a lateral slender process. Furthermore, the new species has the apical portion of the phallus similar to that of O. caatinga , but in O. sagitta sp. nov. the lateral process is curved toward the left under the ejaculatory duct, while in O. caatinga this process is curved toward the right over the duct. The new species can also be diagnosed from other species in this group by the subpentagonal segment IX with a short, triangular mesal projection on its posterior margin, and by the apical portion of the left process of tergum X being wider and arrowhead-like.

Description. Male. General color uniform brown (in alcohol). Body length from tip of head to ends of folded wings: 3.2 mm; length of each forewing: 2.8 mm (holotype male). Tibial spur formula 1,3,4; hind tibiae densely setose, with long, dark setae. Wing venation typical for the genus. Metascutellum subpentagonal. Abdomen without visible modifications.

Male genitalia. Segment IX in lateral view subtriangular, setose, with anterior and posterior margins crenulated, ventral margin long, convex ( Fig. 2A ); dorsum IX not divided, oval ( Fig. 2B ); venter IX subpentagonal, with small, mesal triangular projection at posterior margin; posterolateral margins acute ( Fig. 2C ). Tergum X divided longitudinally into two asymmetrical sclerotized processes: in dorsal view central process large, wider at base, strongly tapering to apex from apical half, with scaled region at left side near base, left process deriving from base of central process, uniformly narrow, except for wider, arrowhead-like apex, curved toward right under central process ( Fig. 2B ). Inferior appendages, in lateral view, oblong, very long, with rounded apices, apicoventral margins crenulate ( Fig. 2A ); in dorsal view narrow and with inner surfaces bearing numerous dark, peg-like setae more dense apically ( Fig. 2B ); in ventral view wide basally, tapering apically ( Fig. 2C ). Phallus tubular, long, slender; ejaculatory duct protruding apically, with right apicolateral process curved toward left under duct ( Fig. 2D ).

Holotype male: BRAZIL: Rio de Janeiro: Rio de Janeiro, Parque Nacional da Tijuca, Rio Cova da Onça, 22°57’45.2”S, 43°17’36.5”W, 494 m, 12.viii.2016, JL

Nessimian, LL Dumas, BM Silva & FQ Machado leg. ( DZRJ).

Etymology. The specific epithet, sagitta (Latin, sagitta , arrow), refers to the arrow-like apex of the left lateral process of tergum X.

Figures

FIGURE 2. Ochrotrichia sagitta sp. nov., holotype male. 2A, genitalia, left lateral; 2B, genitalia, dorsal (setae omitted from right side); 2C, genitalia, ventral (setae omitted from left side); 2D, phallus, dorsal.