Forcipomyia (Euprojoannisia) bibaana Spinelli 2017, new species

Forcipomyia (Euprojoannisia) bibaana, new species

(Figs. 1–5)

Type material. Male. Holotype. MEXICO, Oaxaca, Municipio San Juan Guichicovi, Localidad El Zacatal, Malaise trap, 26̄ 28-July-2009, Salceda, S.B., Rodríguez, A.A. & Ordóñez, A.J., Coll., 1 male (CAIM).

Diagnosis. Male: Only species of Neotropical Forcipomyia (Euprojoannisia) with posterior margin of sternite 9 with two distinctive lateral, triangular lobes and a posteromesal, rounded setose lobe; gonocoxite L-shaped with stout anteromesal projection bearing pair of short, very stout spines, aedeagus short, stout. Female unknown.

Description. Head. Brown. Eyes abutting medially for length of four ommatidia, without interommatidial spicules. Antenna (Fig. 1) with well developed plume, extending to base of flagellomere 13, flagellomeres 2̄9 spherical, 5̄9 fused, 10 1.6 x longer than 11, 10̄13 elongate; flagellomere 13 with apical nipple, not constricted basally; antennal ratio 0.37. Palpus with third segment elongated, with rounded deep sensory pit; segments 4, 5 partly fused; palpal ratio 3.0.

Thorax. Pale yellowish; scutellum with 8 setae. Legs light brown; prothoracic tarsal ratio 2.2; mesothoracic tarsal ratio 1.7; metathoracic tarsal ratio 1.6. Wing (Fig. 2) pale, without pattern; base of M2 not visible; 1 st radial cell obliterated, 2nd radial cell well developed; cubital fork distal to level of apex of costa; apices of CuA1,CuA2 obsolete; wing length 1.07 mm, breadth 0.35 mm; costal ratio 0.48. Halter whitish.

Abdomen. Pale brown. Genitalia (Figs. 3 ̄5) brown. Tergite 9 short, extending to 1/4 length of gonocoxite; posterior margin truncate, with elongate convergent apicolateral process bearing few apical setae; cercus lobēlike. Sternite 9 moderately narrow anteriorly, becoming increasing broader posteriorly; posterior margin with two deep apicolateral excavations that produce two distinctive elongate apicolateral triangular lobes and a rounded posteromesal setose lobe. Gonocoxite L-shaped, 1.1x longer than greatest breadth, with stout anteromesal projection bearing pair of short, very stout spines; gonostylus 0.9 length of gonocoxite, slightly curved apically, tapering to pointed tip. Parameres absent; gonocoxal apodemes slender, V-shaped. Aedeagus very short, stout; basal arms broad, heavily sclerotized, apices recurved; basal arch very shallow, extending 1/20 of total aedeagal length; portion distal with short process hook-shaped, bent ventrocephalad.

Female. Unknown.

Derivation of specific epithet. The specific epithet is from the Zapotec language, bibaana =strange, in reference to the unusual shape of the male gonocoxite.

Distribution. This species is known only from the type locality, El Zacatal, in the state of Oaxaca, Mexico.

Taxonomic discussion. The peculiar L-shaped gonocoxite and the trilobed posterior margin of the sternite 9 clearly distinguish F. bibaana from all other Neotropical and Nearctic species of the subgenus in which the male sex is known. The anteromesal projection of gonocoxite bearing pair of short, very stout spines, is distinctive character of this new species.