Abrhexosa patriciae, Huerta, Heron & Dzul, Felipe, 2013

Huerta, Heron & Dzul, Felipe, 2013, First record of the genus Abrhexosa Freeman from Mexico, with the description a new species, and two new species and new records of the genus Swammerdamella Enderlein (Diptera: Scatopsidae), Zootaxa 3693 (1) : -

Abrhexosa patriciae sp. nov.

( Figs 1–3 )

Type material. Holotype male, labelled: Mexico, Guerrero, Chilpancingo, Ayutla de los Libres, Localidad La Unión, Rancho “El Camalote”, Trampa Malaise, 7-Abr-16-May-2009, 70 msnm, col. W. B. Marin, in CAIM. 2 Paratypes: 1 male, Mexico, Tabasco, Ciudad de Villahermosa, Centro, Zoológico, Trampa Malaise, 23-Dic-2008 al 8-Ene-2009, Col. A. Villanueva; 1 male, Mexico, Oaxaca, Bahías de Huatulco, La Crucecita, parque central, colecta directa, posado en brazo, 26-Jun-2012, Col. Huerta, H. (dissected), in CAIM..

Diagnosis. The shape of abdominal sternite 7, with posterior margin deeply emarginated medially, allows an easy separation from the vicinous Abrhexosa panamensis (Cook) , which has sternite 7 with a shallow median posterior emargination.

Description. Male. Head dark brown. Eyes with interommatidial spicules; antenna with 8 flagellomeres, uniformly dark brown; pedicel subcylindrical, bearing a single whorl of setae, near the distal margin; flagellomeres I to VII wider than long, distal flagellomere club-shaped, flagellum length, 0.22–0.25 (0.23 mm, n=3); palpus brown, stout, large, sensilla scattered on the segment, length, 0.08–0.10 (0.092 mm, n=3); cardo-stipes with 20–21 setae; labellum light brown, setose.

Thorax. Dark brown. Scutum covered with sparse short setae; 11 supra-alar setae; anterior spiracular sclerite with 21–22 setae; anepisternum with 22 scattered setae; 6 sub-alar setae; anterior part of katepisternum with 5 setae; posterior spiracular sclerite with 7 setae; 4 meral setae. Legs ( Fig. 1 ) brown; coxae dark brown; fore and mid femur dark brown, hind femur brown, with pale spot on middle; tibiae brown, darker basally, with pale ring medially, more distinctive on hind tibia; tarsi pale yellow.

Wing ( Fig. 2) length 1.27 mm, width 0.54 mm; hyaline; membrane entirely covered with dense, minute, light micropilosity, posterior margin with a row of marginal setae extending to apex of M2; radial veins extending 0.51 of wing length, brown; 13 dorsal setae on basal portion of R, 20 dorsal setae on R4+5, 4 dorsal setae on R1; posterior veins translucent; fork of M before level of the apex of C, M1 and M2 diverging markedly towards apex of wing; M1, M2, CuA1 and CuA2 reaching wing margin; false vein faint; CuA1 ending beyond level of apex of C; CuA2 sigmoid, ending before level of apex of C.

Abdomen: Dark brown; tergite 6 quadrangular, length, 0.17 mm, width, 0.22 mm; posterior margin with shallow emargination; sternite 6 simple. Sternite 7 ( Fig. 3 B) trapezoid, length, 0.16 mm, width, 0.37 mm with anterior margin rounded and with posterior margin deeply emarginated medially, bearing a pair of laterodistal projections; two separated oblique sclerites disposed along the segment. Tergite 7 ( Fig. 3 A) mostly unsclerotized, length, 0.19 mm, width, 0.32 mm; anterior margin rounded, posterior margin strongly sclerotized, lip-shaped; ventrally apair of short, sclerotized sclerites at apex. Genital capsule ( Fig. 3 C–D), length, 0.24 mm, width, 0.096 mm; aedeagus long, with a coiled projection, ending with a thin filament; parameres lobed, setose, with 10 setae on middle, 7–9 setae laterobasally; an additional simple and setose process, similar in length to the paramere present; tergite 9 bilobed apically, setose.

Female. Unknown.

Distribution. Neotropical. Mexico (Tabasco, Oaxaca, Guerrero).

Etymology. We name this species after Ms. Patricia E. Gomora Rosales, for her support of our work through many years.

Discussion. This new species is very close to Abrhexosa panamensis (Cook, 1956) , from which it may be distinguished by posterior margin deeply emarginated of the sternite 7 and male genitalia with an additional simple and setose process, whereas in A. panamensis the posterior emargination of sternite 7 with a shallow median posterior emargination and has no setose process. The characters of aedeagus, parameres and tergite 9 are very similar in both these species.

Figures

FIGURE 1. Abrhexosa patriciae sp. nov. Legs. A. Fore B. C.

FIGURE 3. Abrhexosa patriciae sp. nov. Male. A. Tergite 7, dorsal view; B. Sternite 7, dorsal view; C. genitalia, ventral view; D. genitalia, lateral view.