Oxyethira (Tanytrichia) singularis, De Souza, Wagner Rafael M. & Santos, Allan Paulo Moreira, 2017

De Souza, Wagner Rafael M. & Santos, Allan Paulo Moreira, 2017, Taxonomic study of the genus Oxyethira Eaton 1873 (Trichoptera: Hydroptilidae) from Northeast Brazil: Eleven new species and distributional records, Zootaxa 4236 (3), pp. 484-506 : 500

Oxyethira (Tanytrichia) singularis sp. nov.

Fig. 10A–10 D

Description. Holotype. Length 2.2 mm. General color pale brown (in alcohol). General pattern of Neotropical Oxyethira . Sternum VII with posterior mesoventral process ( Figs. 10A, 10 C).

Male genitalia: Segment VIII annular, covered with setae; sternum with deep posteromesal incision truncate anteriorly, almost reaching anterior margin of segment ( Fig. 10A ); tergum VIII with posterior margin slightly concave ( Fig. 10 B). Segment IX retracted in segment VIII, sternum produced anteriorly into anterior region of segment VI, with anterior margin convex ( Figs. 10A, 10 B). Inferior appendages elongate, apices darkened; fused to sternum IX basally and to each other, straight, apical margin with small rounded notch between them ( Fig. 10A ); in lateral view, broad basally, constricted subapically, with apex curved slightly dorsad ( Fig. 10 C). Subgenital plate conspicuous; with pair of very long, slender processes initially directed ventrad and then recurved dorsad and caudad ( Fig. 10 B); in ventral view, with pair of anterolateral lobes directed anterolaterad ( Fig. 10 B); in dorsal view rectangular ( Fig. 10A ). Bilobed process with elongate, digitiform processes, each with small apical seta ( Fig. 10 B). Tergum X membranous. Phallus tubular, simple, with broader base and even broader apical membranous lobe having sclerotized lateral margins; ejaculatory duct not protruding ( Fig. 10 D).

Remarks. This new species is assigned to Tanytrichia due to the apical membranous lobe of the phallus with sclerotized margins and the elongate segment IX, produced anteriorly to segment VI. The new species can be identified by the extremely long dorsal processes on the subgenital plate and by the sinuous lateral processes on the phallus. The subgenital plate bearing complex processes is also present in O. gracilianoi sp. nov., but the structure is quite different, being straight and thick, with a preapical spine in O. gracilianoi sp. nov., while in O. singularis sp. nov. these processes are slender, curved, and without spines.

Etymology. The new species is named in reference to its remarkable morphology among Oxyethira species. The word singularis means “unique, characteristic, strange.”

Material examined. Holotype. BRAZIL: Bahia: Barreiras, cachoeira Acaba Vidas , 12°08'00”S, 44°59'00”W [approximate coordinates], 14.x.2008, AR Calor col., light trap, 1 male (MZUFBA). Paratypes. Same data as holotype, 2 ♂ (DZRJ).

Figures

FIGURE 10 A – 10 D. Oxyethira singularis sp. nov. Male genitalia: 10 A, ventral; 10 B, dorsal; 10 C, left lateral; 10 D, phallus, dorsal.