Gauromydas mateus Calhau, Lamas & Nihei, sp. nov.
Creators: name: Calhau, Julia
name: Lamas, Carlos José Einicker
name: Nihei, Silvio Shigueo
Publisher: name: Zenodo
Year: 2015
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Mydidae
Gauromydas
Gauromydas mateus

description: Gauromydas mateus Calhau, Lamas & Nihei sp. nov.
(Figs 2 A–F, 4A–C, 5A–C, 6)
Diagnosis. Scutum velvety-black with discrete gray pruinescence, more distinct on acrostichal stripes. Male hind femur about 2 times wider than hind tibia. Hind tibia with well-developed ventral keel and apical spur. Hind tarsomere 1 about 2.8 times longer than wide, and 1.6 times longer than tarsomere 5. Wing membrane light brown, transparent, without opaque areas (at most with semi-transparent regions at base and on posterior margin); alula higher than wide. Abdominal T2–5 partially orange, or all brown. Male epandrial lamellae triangular with posterior extremity prolonged as a distinct spine; phallic crest thick, membranous, strongly sclerotized anteriorly, lateral projections reduced. Anterior margin of female S8 concave; furca well sclerotized; female S10 sclerotized medially; sclerite at base of spermathecal ducts wider than cercus.
Description. Male. Total length of holotype, excluding antennae, 29 mm (Fig. 2 A). Head (Fig. 2 B): Black, setulae dark brown to black, pruinescence gray; 4.3 mm high in lateral view, 6.15 mm wide in anterior view (holotype). Facial gibbosity dark brown, higher than wide; mystax dense, medially brown, laterally white. Mouthparts: proboscis black. Antennae: scape and pedicel black, setulae all black. Measures in holotype: scape 0.75 mm long; pedicel 0.23 mm long. Thorax (Fig. 2 A): dark brown. Setulae of scutum black, distributed anteriorly on dorsocentral area, lateral margins, postalar callus and posteriorly close to scutellum; pruinescence discrete, gray, denser on acrostichal stripes. Pleuron scarcely gray pruinose. Anepisternum black setulose on dorsal margin. Anepimeron, metepimeron, metakatepisternum, prosternum, proepisternum, mesosternum and scutellum, long black setulose. Male paratype with cuticular projection on prothoracic spiracle margin (Fig. 2 F). Legs (Fig. 2 C): dark brown; setulae mostly short, black. Hind femur 10.54 mm long, 1.78 mm wide (holotype), with 15–17 black spiniform macrosetae (17 in holotype), distributed into anteroventral and anterodorsal rows and scarce long erect dorsal and posteroventral setulae. Fore and mid tibiae densely setulose; hind tibia 7.94 mm long, 0.89 mm wide (holotype), ventral keel developed, apical spur 0.85 mm long (holotype) with strong anteroventral setulae at base of spine. Measures of hind tarsus in holotype: tarsomere 1 1.64 mm long, 0.59 mm wide; tarsomere 2 0.92 mm long; tarsomere 3 0.92 mm long; tarsomere 4 0.52 mm long; tarsomere 5 1.05 mm long. Pulvillus pale brown, shorter than fore, mid and hind tarsomeres 5; claws reddish brown, tip black. Wing (Fig. 2 E): 24.93 mm long, 8.35 mm wide; alula 2.5 mm long, 2.94 mm wide (holotype). Membrane light brown; transparent, without opaque areas, at most with semi-transparent regions at base and on posterior margin; microtrichia absent. Veins orange to brown; C with short black setulae on anterior wing margin and very short brown microtrichia on posterior wing margin; Sc ending in C slightly distal to fork of R4+5; R3 (‘stump vein’) emerging from R4, a little after base; cell r4 closed (R5 terminating in R1); CuA1+M3 present. Upper calypter dark brown, broader distally; marginal squamous setulae dark brown. Halter dark brown. Abdomen (Fig. 2 C): T2–5 mostly orange, laterally dark brown, remaining tergites and sternites dark brown (holotype) or all brown with discrete metallic tergites. Anterior portion of T1 cone shaped, pointed, with few black setulae close to base of halter; posterior portion long black setulose. T2–T7 and S2–S7 short black setulose, very scarcely pruinose, shinny. Bulla black, about 6 times as long as wide. Male terminalia (Figs 4 A–C): epandrial lamella triangular with posterior extremity prolonged as distinct spine. Phallus with thick membranous dorsal structure (phallic crest), strongly sclerotized anteriorly; lateral projections reduced. Female. Total length, excluding antennae, 38.2 mm (Fig. 2 E). Very similar to male holotype in color and chaetotaxy, but distinctly more robust and larger than male. T6–7 with violet metallic reflection. Female terminalia (Figs 5 A–C): anterior margin of S8 concave; S10 sclerotized medially; furca well sclerotized; sclerite at base of spermathecal ducts wider than cercus.
Etymology. The specific epithet is a patronym with noun in apposition, honoring Mateus I. C. Kawada, son of the first author.
Remarks. This is the only Gauromydas species with orange coloration on abdominal tergites. Despite the male paratype differing from the holotype in coloration and the cuticular projection on spiracular margin, these differences are here considered intraspecific variation, as they have identical terminalia.
Type material. HOLOTYPE ♂. ARGENTINA. Santiago del Estero, 1936, E.R. Wagner col. (MNHN). PARATYPES. ARGENTINA. Salta: Rio Pescado, ca. Urán, 22.53S, 64.27W, C. Potter col. (1 ♂, MZUSP); no data (1 ♀, MZUSP).
description: Published as part of Calhau, Julia, Lamas, Carlos José Einicker & Nihei, Silvio Shigueo, 2015, Review of the Gauromydas giant flies (Insecta, Diptera, Mydidae), with descriptions of two new species from Central and South America, pp. 392-411 in Zootaxa 4048 (3) on pages 402-403, DOI: 10.11646/zootaxa.4048.3.3, http://zenodo.org/record/245783