Orinocotrichia costae, Cavalcante-Silva & Santos & Calor, 2025

Cavalcante-Silva, Amanda, Santos, Allan Paulo Moreira & Calor, Adolfo Ricardo, 2025, Three new species of Stactobiinae (Trichoptera: Hydroptilidae), new distributional records, and an updated checklist for Brazil, Zootaxa 5659 (1), pp. 87-103 : 93-95

Orinocotrichia costae sp. nov.

( Figures 4A–4H )

Material examined. Holotype male. BRAZIL: Roraima: Amajari, Estação Ecológica de Maracá, Rio Uraricoeira , white sheet attraction, 03°20’59”N, 61°25’22”W, el. 83 m, 24.iii.2016, A.P.M. Santos, A.L.D. Ferreira, C.C. Gonçalves leg., 1 male ( DZRJ 7667 ) . Paratypes. Same data as holotype except A.P.M. Santos, A.L.D. Ferreira, C.C. Gonçalves leg., 1 male ( DZRJ 7668 ), same data as holotype except A.P.M. Santos, D.M. Takiya, C.C. Gonçalves, C. Maldaner, A.L.D. Ferreira leg., 1 male ( DZRJ 7681 ) .

Description. Holotype. Adult male. Length 1.5–1.7 mm (mean 1.6, n = 3), holotype 1.7 mm (from tip of the head to wing apex). Forewing length 1.3–1.5 mm (mean 1.4, n = 3), holotype 1.5 mm. General color, in alcohol, pale yellow. Antennae 18-segmented, unmodified, with short pale brown setae; scapus cylindrical, pedicel cylindrical,

apical flagellomere short and with small projection ( Fig. 4A ). Ocelli absent. Posterior setal warts of head triangular. Maxillary palps 5-segmented; labial palps 3-segmented. Legs covered by golden setae, tibial spur formula 0–2–3. Wings unmodified, without flaky patches; fore- and hind wings with main veins present ( Figs 4B, 4C ). Forewings, in alcohol, uniformly brown, with brown setae; each with Sc incomplete, ending in middle of wing length; apical forks 1, 2, and 3 present; veins 3A and 2A crossing each other subapically ( Fig. 4B ). Hind wings narrow, more acute than forewings; each with Sc incomplete; apical forks 1 and 2 present ( Fig. 4C ). Mesoscutellum with transverse suture. Metascutellum rectangular, short and wide. Sternite VII without apicomesal process ( Figs 4E, 4F ).

Male genitalia. Segment VIII annular. Segment IX reduced dorsally ( Fig. 4D ); with elongate apodemes originating laterally, extending into segment VI, in dorsal, lateral, and ventral views ( Figs 4D–4F ); posterolateral margins each with large round lateral lobe bearing long seta, in ventral and lateral views ( Figs 4E, 4F ), and elongate and obliquely truncate apicolateral processes in dorsal view ( Fig. 4D ). Tergum X membranous; round apically ( Fig. 4D ). Inferior appendages very short, each with apically blunt ventromesal membranous projection in ventral and lateral views ( Figs 4E, 4F ), lateral margin with mesal invagination in ventral view ( Fig. 4E ); subrectangular, in lateral view ( Fig. 4F ). Subgenital plate conspicuous and elongate, in ventral view ( Fig. 4E ); divided into pair of contiguous arms with rounded apices ( Figs 4E, 4F ). Phallus tubular, divided into two long, symmetrical arms, and strongly recurved laterodorsad apically, in ventral view, with ejaculatory duct mesal and elongate between lateral arms ( Fig. 4G ).

Remarks. The male genitalia of O. costae sp. nov. are morphologically similar to those of O. calcariga , especially in the large lobes on the posterolateral margins of segment IX ( Fig. 4E ) and in the phallus divided into two symmetrical arms, strongly recurved apically, with a mesal ejaculatory duct ( Fig. 4G ). Orinocotrichia costae sp. nov. differs from O. calcariga by the obliquely truncate processes of segment IX ( Fig. 4D ) and by the subgenital plate conspicuous and divided mesally ( Fig. 4E ), which in O. calcariga is reduced and not divided. The structure of the conspicuous and divided subgenital plate of O. costae sp. nov. is similar to that of O. angelus . The new species can be distinguished from this species by the shape of the apicolateral processes of segment IX, in dorsal view ( Fig. 4D ), by the inferior appendages each with an acute ventromesal membranous projection in ventral view ( Fig. 4E ), and by the phallus apex, with strongly recurved lateral arms ( Fig. 4G ).

Etymology. This species is named in honor of psychologist Andreia Pereira Costa, Salvador City, Brazil, for her dedication to caring for the mental health of postgraduate students.

Distribution. Brazil (RR).

Figures

FIGURE 4. Orinocotrichia costae sp. nov., male: 4A, apical flagellomeres, frontal; 4B, right forewing, dorsal; 4C, right hind wing, dorsal; 4D–4H, genitalia: 4D, dorsal; 4E, ventral; 4F, left lateral; 4G, phallus, dorsal; 4H, phallus, left lateral. Scale = 0.1 mm.