Ochrotrichia nematomorpha, 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 : 230-232

Ochrotrichia nematomorpha , new species

( Fig. 1A–1D )

Diagnosis: Ochrotrichia nematomorpha sp. nov. can be placed in the O. xena Group of Flint (1972) as indicated by the overall arrangement of male genital structures, especially by segment X occurring as a single, broad, elongated plate. The new species is most similar to O. igrapiuna Souza, Santos & Takiya 2014 in the long subtriangular tergum X with its projected posterior margin. However, O. nematomorpha sp. nov. can be easily distinguished from O. igrapiuna by the membranous right side and the median membranous handle-like process of tergum X, by the robust and diamond-shaped inferior appendages with apical and posteroventral clusters of peglike setae, and the phallus being extremely slender, long and acute apically.

Description: Male. General color uniform brown (in alcohol). Body length from tip of head to ends of folded wings: 3.0 mm; length of each forewing: 2.3 mm (holotype male). Tibial spur formula 1,3,4. Wing venation typical for the genus. Metascutellum subpentagonal. Abdomen without visible modifications.

Male genitalia. Segment IX in lateral view subquadrangular, anterior margins dorsally and ventrally produced anterad and anterolateral margins concave at midheight, posterior margins dorsally produced posterad ( Fig. 1A ); dorsum IX with deeply U-shaped cleft posteriorly, almost entirely divided into two lobes ( Fig. 1B ); venter IX subpentagonal ( Fig. 1C ). Tergum X in lateral view long, not divided, broad at base and tapering to acute apex from about midlength ( Fig. 1A ); in dorsal view subtriangular, narrow, with biconcave base, left side slightly sclerotized, right side membranous and bearing mesal, membranous handle-like projection ( Fig. 1B ). Inferior appendages, in lateral view, robust, short, diamond-shaped, anterodorsal, posterodorsal, and posteroventral margins rounded, with long setae covering surfaces ( Fig. 1A ); in dorsal view wide basally with dorsolateral fold ( Fig. 1B ); in ventral view tapering, with clusters of dark, peg-like setae apically and subapically on inner edges ( Fig. 1C ). Phallus tubular, long, extremely slender, very acute at apex; ejaculatory duct not protruding apically ( Fig. 1D ).

Holotype male: BRAZIL: Rio de Janeiro: Rio de Janeiro, Parque Nacional da Tijuca, Rio Tijuca, Cascatinha Taunay , 22°57’33.7”S, 43°16’40.2”W, 407 m, 11.iv.2014, JL Nessimian, LL Dumas, CC Gonçalves, BM Silva & SP Gomes leg. ( DZRJ) .

Distribution. Brazil (Rio de Janeiro).

Etymology. The specific epithet, nematomorpha (Greek, nema, thread; morpha, shape), refers to the slender, long phallus, which resembles the body shape of horsehair worms (Phylum Nematomorpha).

Figures

FIGURE 1. Ochrotrichia nematomorpha sp. nov., holotype male. 1A, genitalia, left lateral; 1B, genitalia, dorsal (setae omitted from right side); 1C, genitalia, ventral (setae omitted from left side); 1D, phallus, dorsal.