Acellomyia casablanca, González, 2017

González, Christian R., 2017, The genus Acellomyia González, a new taxonomic arrangement of its species and descriptions of a new genus and two new species from southern South America (Diptera: Tabanidae: Diachlorini), Zootaxa 4337 (4), pp. 523-539 : 525-526

Acellomyia casablanca sp.n.

( Figs. 1a–k )

Type locality: Antillanca , Osorno Province, Chile.

Diagnosis. Medium-sized species (15.5–16.5 mm). Body color brownish ( Fig. 1a ). Eyes with abundant short gray ommatrichia, without bands. Frons broad, gray, slightly divergent. Basal callus shining brown, subrectangular, with dorsal projection. Subcallus covered with brownish pruiniscence, and short gray setae. Antennae bicolored, scape grayish, pedicel and first flagellomere dark brown; basal plate angulate on dorsal surface. Maxillary palpus elongated yellowish, bearing yellowish pruiniscence and abundant short black and yellowish setae. Mesonotum dark gray, with long yellowish setae, bearing three narrow longitudinal pale stripes beyond transverse suture. Wing lightly smoky, without appendix on R4. Abdomen light brown dorsally, with yellowish setae, pale yellowish laterally on tergites 1–3. Tergites 1–6 with broad blackish pruiniscence and median posterior spots. Sternites brownish, mostly black haired.

Description (Holotype ♀).

Female. Head. Eye dark brown, without bands, with abundant short gray ommatrichia. Frons gray with brown pruiniscence, mostly on the vertex, bearing short black setae. Frons wide, slightly divergent, frontal index 1.78– 1.84; ocellar triangle and ocelli absent. Basal callus shining brown, subrectangular, with dorsal projection and irregular upper border, touching eyes and subcallus ( Fig. 1b ). Posterior border of the head gray with short black and gray setae; vertex with short black and whitish setae. Subcallus covered with brownish, pruiniscence, and abundant, short gray setae. Clypeus and genae yellowish pruiniscence, genae with short black and whitish setae, black setae concentrated near subcallus, clypeus bearing long whitish setae and a few short black setae. Beard with long whitish setae ( Fig. 1c ). Scape of antenna grayish, with both short and long black setae. Pedicel dark brown and with very short black setae. First flagellomere dark brown, angulate on dorsal surface, flagellomeres concolorous with first flagellomere ( Fig. 1d ). Maxillary palpus elongated yellowish, bearing yellowish pruiniscence and short black setae, and a very few whitish setae ( Fig. 1e ). Proboscis blackish, labellum black, large and fleshy. Thorax. mesonotum dark gray, with long yellowish setae, bearing three narrow longitudinal pale stripes beyond transverse suture. Postpronotal lobe dark gray, with long yellowish and whitish setae. Scutellum dark gray, with long yellowish setae on the disc and on the base ( Fig. 1f )). Pleura coated with grayish pruiniscence, with long yellowish and whitish setae. Legs brownish, coxa grayish. Femur with long whitish and short black setae, tibia shorter. Tarsus with short black setae. Wing lightly smoky, without appendix on R4 ( Fig. 1g ). Basicosta bare. Halter light brown. Calypter concolorous with base of wing. Abdomen. light brown dorsally ( Fig. 1h ), with yellowish setae, pale yellowish laterally on tergites 1–3, posterior border of tergites with distinct narrow yellowish hind margins and yellowish setae. Tergites 1–6 with broad blackish pruiniscence and median posterior spots. Tergite 7 with pruiniscence and pale yellowish setae. Sternites brownish, mostly with black setae. Terminalia. Cerci with apex subtriangular; tergite 10 subrectangular, with the tip rounded; tergite 9 subtriangular, with long setae ( Fig. 1i ). Gonapophysis with border concave and long setae; sternite 8 broad with narrow base ( Fig. 1j ). Genital fork with wide base, concave and short sperm pump ( Fig. 1k ).

Male: Unknown.

Variability. Length 15.5–16.5 mm; wing 14. 0–14.5 mm; frontal index 1.78–1.84 (n = 10). There is some variation, especially in distribution of black setae of the maxillary palpus, the length of the median projection of the basal callus (longer in some specimens), and color of abdominal tergites.

Distribution. Chile (Osorno Province).

Type-material. Holotype ♀, Chile, Osorno Province , Antillanca (40º47'25.96''S / 72º11'24.69''W) 1377 masl, 2.II.1992, C.R. González ( IEUMCE) . Paratypes: 2 ♀ with the same data of Holotype ( IEUMCE) , 3 ♀ Antillanca , 8.II.2003, A. Vera ( IEUMCE) , 5 ♀ Port of Puyehue , 19.I.1969, L.E. Peña ( IEUMCE) .

Etymology. The specific name is a noun in apposition taken from Volcán Casablanca near the type locality.

Figures

FIGURE 1. Holotype female of Acellomyia casablanca sp. n. a. Habitus (scale bar = 5.0 mm); b. Head in frontal view; c. Head in lateral view; d. Antennae (scale bar = 0.5 mm); e. Maxillary palpus (scale bar = 0.5 mm); f. Mesonotum in dorsal view; g. Wing; h. Abdomen in dorsal view; i. Cerci, tergite 9 and 10; j. Gonapophysis and sternite 8, dorsal view; k. Genital fork and spermathecal ducts (scale bar = 1 mm).