Oxyethira maranhensis, 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 : 495-498

Oxyethira (unplaced) maranhensis sp. nov.

Fig. 8A–8 D

Description. Holotype. Length 2.0 mm. General color pale brown (in alcohol). General pattern of Neotropical Oxyethira . Sternum VII without posterior mesoventral process ( Figs. 8A–8 C).

Male genitalia: Segment VIII annular, covered with setae; sternum with deep V-shaped posteromesal incision almost reaching anterior margin of segment ( Fig. 8A ); tergum subrectangular, posterior margin with deep and broad oval incisionbetween posterolateral projections ( Fig. 8 B). Segment IX retracted in segment VIII, sternum subtriangular, produced anteriorly into mesal area of segment VI, with anterior margin rounded; segment IX asymmetrical posteriorly, bearing two distal processes on left side: Left anterolateral process short, curved dorsomesad, and dark; left posterolateral process arising beyond base of anterolateral process, elongate, sinuous, with darkened apex protruding beyond left lateral margin of segment VIII ( Figs. 8A, 8 B); sternum IX with oblique darkened stripe reaching bases of both processes; tergum IX reduced. Inferior appendages indistinct. Subgenital plate inconspicuous, in ventral and dorsal views appearing as small transverse sclerite ( Figs. 8A, 8 B); in lateral view tall, not protruding beyond segment VIII ( Fig. 8 C). Bilobed process bearing pair of slender processes, each with small apical seta ( Figs. 8A, 8 B), not visible beyond segment VIII in lateral view. Tergum X membranous. Phallus short and broad, constricted sub-basally, with conspicuous slightly sclerotized flap, apical portion narrowing abruptly in acute apex; with membranous apicoventral lobe; ejaculatory duct membranous, protruding at median region ( Fig. 8 D).

Remarks. This species is not assigned to any subgenus. Although, the new species has a deep incision in sternum VIII similar to that described for Loxotrichia species, it lacks the typical inferior appendages of this subgenus. As with Oxyethira rareza Holzenthal & Harris 1992 and O. quinquaginta Kelley 1983 (both incertae sedis), the new species has asymmetric male genitalia and vestigial inferior appendages. Oxyethira maranhensis sp. nov. can be recognized by asymmetrical segment IX, which bears two processes at the left side: one elongate, sinuous, with darkened apex protruding beyond the segment VIII, and another, short, curved, darkened, positioned at the base of the former; by the absence of the inferior appendages, and by the phallus with a conspicuous, slightly sclerotized flap and an acute apex.

Etymology. The specific name is a reference to those born in the Maranhão State, where the holotype was collected.

Material examined. Holotype. Brozil: Maranhão: Carolina, Parque Nacional da Chapada das Mesas , riacho Cancela atrás da Fazenda Cancela, 7°6'43''S, 47°17'46''W, 186 m, 21.ix.2014, TT Andrade & WRM Souza cols., light trap, 1 ♂ ( DZRJ).

Figures

FIGURE 8 A – 8 D. Oxyethira maranhensis sp. nov. Male genitalia: 8 A, ventral; 8 B, dorsal; 8 C, left lateral; 8 D, phallus, dorsal.