Geloemyia namibica V. Korneyev, 2015

Korneyev, V. A., 2015, Review Of The Genus Geloemyia (Diptera, Pyrgotidae), With Discussion Of Its Taxonomic Position, Vestnik Zoologii 49 (6), pp. 497-518 : 508-510

Geloemyia namibica V. Korneyev , sp. n. (fig. 1, 11, 17, 55–66)

M a t e r i a l. Type. Holotype ♀: Namibia: Rundu Dist., Kotara Okavango River , 17̊48'56" S 18º53'38" E, light trap sample, 22–23.i.1998 (Kirk-Spriggs & Marais) ( NICW) . Paratypes 3 ♀: Namibia: same label as in the holotype ( NICW; SIZK); 1 ♂: Mahango Game Reserve , 1–3.x.1993 (Koch) ( MNKB) .

D i a g n o s i s. This species can be recognized from combination of the head triangular in profile, with the parafacial dorsally 1.5–2× as long as flagellomere 1, face strongly receding, and peristomal cavity very short (as long as or slightly shorter than parafacial), ocellar setae long, one pair of orbital setae; wing with mottled pattern covering whole disk, including anal cell and lobe; vein R 2+3 with stump vein; vein R 4+5 setulose dorsally; crossvein dm-cu forming almost right angle (80–85°) with vein CuA 1; mesonotum with 1 presutural and 3 postsutural dorsocentral setae; scutellum with 2 pairs of setae but without setulae; female mid femur without femoral organ; oviscape slightly longer than tergites 3–6 combined.

D e s c r i p t i o n. Head (fig. 55–58) yellow to brownish yellow, triangular in profile, height: length: width ratio = 1: 1: 1.1; with face strongly receding, and peristomal cavity very short; frontal vitta yellow, matt, microtrichose, black setulose anterolaterally, medially bare, 1.3–1.4× as long as wide in posterior half; parafacial 1.5–2× as wide as flagellomere 1; eye 1.4× as high as wide, 1.4–1.5× as wide as parafacial and 2–2.5× as high as gena. Face concave, with faint medial suture, in ventral one-fourth with short carina. Epistome acute triangular, very long, slightly longer than antennal grooves. Gena with short and low, sometimes brownish, subocular sclerite; postgena anteriorly with 1–2 subequal setae and 7–7 shorter setulae. Occiput entirely yellow. First flagellomere entirely reddish yellow, 1.3× as long as wide, 1.3× as long as pedicel and 2.3× as long as scape. Arista reddish yellow in basal half, 2-segmented, very short pubescent. Scape as long as wide. Palp yellow, oval, 2.5× as long as wide, and as long as first flagellomere. Labellum small, almost as long as palp. Lateral vertical setae (vte) 0.2–0.3× as long as medial vertical setae (vti); vti 3× as long as pedicel, 1.5× as long as ocellar and 3× as long as postocellar and orbital setae and 3–4× as long as setulae (above lunule).

Thorax yellow to brownish yellow, without distinct dark pattern (fig. 60). Prosternum saddle-like, short setulose. Postpronotal lobe with 4–6 setulae and one long seta; proepisternum with 3–5 setae. Scutum as long as wide, subshining yellow with faint brown areas, sparsely black setulose, with white microtrichia not obscuring underlying cuticle; 2 notopleural, 1 presutural and 1 postsutural supra-alar, 1 intra-alar, 1 postalar, 1 short presutural and 2–3 postsutural dorsocentral, and 0–1 acrostichal setae (if present, slightly longer than setulae). Scutellum yellow, whitish microtrichose, with 2 pairs of setae: apical 1.5× as long as scutellum and basal as long as scutellum, but without setulae (fig. 1, 5). Anepisternum yellow, with reddish or brownish anterior part covered with 10–12 short setulae; posterior part with 1–2 long setae and 6–7 irregular long setulae; anepimeron with 1 long seta and 1–2 short setulae; katepisternum with 1–3 long setae and 1–2 thinner and slightly shorter setulae dorsally and 2–3 setae medioventrally, anterior of mid coxa. Katatergite, anatergite and mediotergite matt yellow.

Wing (fig. 1, 59) 2.5–2.6× as long as wide, yellowish or hyaline with mottled pattern of moderately small grey spots partly fused apically and from pterostigma to posterior margin through crossvein r-m, and dark spots in anterior cubital and anal cells, anal lobe and alula; veins brown or yellowish. Costa with conspicuous humeral and subcostal break, subcostal vein broken at apex and not joined to costa. Pterostigma half as long as costal cell. Vein R 2+3 sinuate, with stump vein. Vein R 4+5 dorsally setulose over almost entire length. Cell cup closed by slightly sinuate crossvein and very short lobe. Wing length 6.0– 6.4 mm. Lower calypter narrow, without cilia; upper calypter with long and dense setulae forming black fringe. Halter creamy white.

Legs (fig. 54) entirely yellow, black setulose and setose. Coxae moderately long and sparsely setose and setulose, unmodified. Fore femur moderately narrow, with basiventral seta and row of 6–7 strong black posteroventral setae as long as femur width and 4–5 shorter and thinner postero-dorsal setae; long setulose on posterior surface. Fore tibia widened apically, with 3–4 short preapical setae on dorsal surface. Fore tarsus unmodified in both sexes, yellow, tarsomere 1 twice as long as tarsomere 2; tarsomere 5 orange, narrow, as wide as tarsomere 3; tarsomere 4 unmodified, as wide as and 0.7× as long as tarsomere 5 (fig. 11). Mid femur unmodified, without long setae, uniformly setulose on anterior surface setose without femoral organ. Hind femur narrow, short setulose, without 2 longer subapical dorsal setae.

Abdomen (fig. 54) moderately wide, as long as thorax, with syntergite 1+2 transverse, 0.6× as long as wide and 0.7× as long as tergites 3–6 combined. Sternites of female wide,with short setulae and long marginal and submarginal setae on posterior margins, synsternite 1+2 trapezoid, sternites 3–5 subrectangular, wider than long; sternite 6 wide trapezoid. Synsternite 1+2 of male triangular, sternites 3–4 very narrow, somewhat widened at anterior margin and with oval posterior portion bearing 6–8 setae and 5-6 short setulae; sternite 5 with narrow anterior half and equilaterally triangular posterior half (fig. 62).

Female genitalia. Oviscape entirely orange (fig. 54), 1.5–1.6 mm long, uncompressed, cylindrical, twice as long as wide basally, sparsely black setulose, and as long as tergites 3–6 combined, with apex short and inconspicuously bent dorsally, laterally bearing long setulae 1.2–2× as long as oviscape width (fig. 17). Dorsal (dorso-medial) lobes short, latero-ventral lobes very short, medial lobe long, twice as long as width of apex. Eversible membrane not examined. Aculeus (fig. 65) basally widened, without preapical constriction, 7× as long as wide at middle. Ventral receptacle as in other Pyrgotinae. Spermathecae oval (fig. 66).

Male genitalia as on figs 63, 64; epandrium and surstyli covered by short setulae inserted into big sockets; dorsal portion of epandrium bearing no long setae, only 4–5 short setae at level of cerci and fusion of epandrium with surstyli; surstyli directed posteriorly, as long as epandrium, robust; inner surstylus without prensisetae; phallus bare, with glans as on fig. 64, very similar to that of G. trifasciata .

Remarks. The main difference of G. namibica sp. n. from most other species of the genus (at least from those known from both sexes) is that it shows no sexual dimorphism in the wing pattern or structure of fore and mid legs; it seems to be related to the Madagascan G. trifasciata as they share the high epistome, developed presutural dorsocentral seta and conspicuously narrowed abdominal sternites of males (possible synapomorphies, not occurring in most other Pyrgotinae except Pyrgotomyia ), in combination with well developed spurious vein on R 2+3 and unmodified fore tarsus of female (possible symplesiomorphies).