Oxyethira (Dactylotrichia) retrosa, 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 : 486-490

Oxyethira (Dactylotrichia) retrosa sp. nov.

Fig 3A–3 D

Description. Holotype. Length: 2.7 mm. General color pale brown (in alcohol). General pattern of Neotropical Oxyethira . Sternum VII with posterior ventromesal process ( Figs. 3A, 3 C).

Male genitalia: Segment VIII annular, covered with setae; sternum completely divided longitudinally ( Fig. 3A ); tergum with posterior margin broadly concave ( Fig. 3 B). Segment IX retracted in segment VIII; sternum produced anteriorly and reaching anterior area of segment VI, with pair of long lateral processes at midlength projected dorsad ( Figs. 3 B, 3C); tergum reduced. Inferior appendages elongate, darkened apically; in ventral view fused basally to sternum IX, digitiform and diverging apically ( Fig. 3A ); in lateral view subrectangular, with same width throughout, curved evenly posterodorsad, and slightly truncate ( Fig. 3 C). Subgenital plate conspicuous; in ventral and dorsal views with posterior margin truncate ( Fig. 3A ); in lateral view tall, projecting caudally beyond segment VIII and with bilobed process about same length ( Fig. 3 C). Bilobed process lobes short and globose, each with small apical seta ( Fig. 3 B). Tergum X membranous. Phallus with apex recurved anterad dorsally, crossing its median portion ( Fig. 3 D); ejaculatory duct not protruding.

Remarks. This species is quite similar to others assigned to the subgenus Dactylotrichia due to sternum VIII completely divided and segment IX reaching beyond segments VIII–VII internally ( Kelley 1984). Among Dactylotrichia species, Oxyethira retrosa sp. nov. is most similar to O. hozosa Harris & Davenport 1999 and O. scaeodactyla Kelley 1983 because of the elongate inferior appendages, but is the inferior appendages are wider in the new species than in those other two. Moreover, segment IX also has lateral projections directed dorsad in both O. retrosa sp. nov. and O. hozosa . The new species is also similar to Oxyethira acegua Angrisano 1995b , both species having a recurved phallic apex. However, in the new species the recurved portion crosses the phallus dorsally, whereas in O. acegua the phallus is recurved anterad laterally. Oxyethira retrosa sp. nov. can also be identified by the tall subgenital plate produced caudad beyond segment VIII and about as long as the lobes of the bilobed process.

Etymology. The specific name is an allusion to the phallus shape. The word “ retrosa ” is derived from Latin “ retrosum ” that means directed backward.

Examined material. Holotype. BRAZIL: Sergipe: Itabaiana , Parque Nacional da Serra de Itabaiana, Riacho dos Negros, 10°44'50''S, 37°20'24''W, 202 m, 17.vi.2014, APM Santos, DM Takiya, AC Domahovski & WRM Souza cols., light trap, 1 ♂ ( DZRJ) . Paratypes. Same data as holotype, 1 ♂ ( DZRJ) ; Alagoas: Quebrangulo, Reserva Biológica de Pedra Talhada, Bica da Juliana , 9°14'21,7''S, 36°27'11,4''W, 20.vi.2014, APM Santos, DM Takiya, AC Domahovski & WRM Souza cols., light trap, 2 ♂ ( DZRJ) . Quebrangulo, Reserva Biológica de Pedra Talhada, Rio Caranguejo , 9°15'26''S, 36°25'54''W, 661 m, 28.viii.2013, LRC Lima col., light trap, 2 ♂ (CE-UFPE).

Figures

FIGURE 3 A – 3 D. Oxyethira retrosa sp. nov. Male genitalia: 3 A, ventral; 3 B, dorsal; 3 C, left lateral; 3 D, phallus, dorsal.