Empis (Empis) windhoekiensis Kustov et Shamshev, 2022

Kustov, S. Yu. & Shamshev, I. V., 2022, Three new species of empidid dance flies of the genus Empis Linnaeus, 1758 (Diptera: Empididae) from Namibia, Russian Entomological Journal 31 (2), pp. 194-200 : 198-199

Empis (Empis) windhoekiensis Kustov et Shamshev , sp.n.

Figs 7–8 .

TYPE MATERIAL. Holotype ♂, Namibia, Windhoek env., 22.545°S 17.255°E, 1870 m, 28–31.i.2021, N. Vikhrev ( ZMMU) . Paratypes: 8 ♂, same data as holotype ( ZMMU, 1 ♂ — ZISP) .

DIAGNOSIS. A species of E. (E.) setitarsus -group; body 3.5–4.5 mm; proboscis short, labrum only slightly longer than head height; laterotergite with black setae; abdomen greyish pruinose, only pale setose; wing with incomplete veins M 1 and CuA+CuP, pterostigma pale yellowish, halter brown. Male: fore basitarsus slightly thickened; wing hyaline.

DESCRIPTION. Body length 3.5–4.2, wing 4.2–4.5 mm. Male ( Fig. 7 ). Head with greyish, dense pruinescence on frons, face, clypeus (except shiny upper margin), ocellar triangle, occiput and postgena; black setose. Eyes holoptic, with upper ommatidia enlarged. Frons represented by very small, subtriangular space just below ocellar triangle and slightly larger space just above antennae. Face broad, almost parallel-sided, bare. Ocellar triangle with several fine setae, 2 setae somewhat longer. Occiput with fine, moderately long postoculars and several similar setae laterally; postgena with numerous hair-like setae. Antenna black; scape short, slightly longer than pedicel, both with short setulae; postpedicel elongate-conical, with lower margin slightly concave distally, nearly 2.5X as long as basal width; stylus short, nearly 2.5X shorter than postpedicel. Proboscis short, with labrum only slightly longer than head height (1.2–1.3X); labium lacking annulations, bearing scattered, minute setulae; labella moderately long, nearly 2X shorter than labrum, with small desclerotized space on about distal 1/3 (visible in situ as notch); palpus black, with black, scattered setulae.

Thorax black in ground-colour, black setose; mesoscutum faintly greyish pruinose (dorsal view), prothoracic sclerites and mesopleuron somewhat denser greyish pruinose.Proepisternum with 4–5 rather short, fine setae on lower part and 4–6 similar setae on upper part. Prosternum bare. Antepronotum with 3 moderately long setae on each side. Postpronotal lobe with 1 strong, long and several fine, short setae. Mesonotal setae well-differentiated; acrostichals moderately long, thin, arranged in 2 close, irregular rows, lacking on prescutellar depression; dorsocentrals longer than acrostichals, 1–2-serial before suture, uniserial and longer along prescutellar depression, 2 prescutellar setae longest; 1 fine, moderately long presutural intra-alar, 1 longer presutural supra-alar, 3 notopleurals (2 setae stronger; additionally, with some setulae anteriorly), 1 postsutural supra-alar (with 3–4 additional short, fine setae anteriorly), 1 long and 1 minute postalars, 4 scutellars (apical setae long and cruciate, lateral setae only slightly shorter). Laterotergite with 5–6 long and some short fine setae. Anterior and posterior spiracles dark brown.

Legs rather robust, black, subshiny (except coxae), faintly greyish pruinose, black setose; coxae densely pruinose. Fore coxa and trochanter almost bare, only with scattered minute setulae; hind trochanter with long, dense setae. Fore femur with row of short anteroventral fine setae on about basal half, almost bare posteroventrally, only some minute posteroventral setulae closer to base. Fore tibia with numerous long, fine setae posterodorsally (longest setae about 2X as long as tibia width). Fore basitarsus thickened but only slightly stouter than fore tibia at apex; with moderately long, dense, fine setae posterodorsally; tarsomeres 1–4 with rather long setae of subapical circlet. Mid femur with complete rows of numerous anteroventral and posteroventral setae, which are long on about middle part of femur and short near its base and apex; longest anteroventral setae nearly 1.5X as long as femur middle width. Mid tibia with several intermixed moderately long to long ad setae closer to base, more or less distinct row of moderately long posterodorsal setae and rows of moderately long anteroventral and short posteroventral setae. Mid basitarsus nearly as broad as mid tibia at apex; tarsomeres 1 and 2 with short spine-like setae ventrally, tarsomeres 1–3 with rather long setae of subapical circlet (longer dorsally). Hind femur with complete rows of long anteroventral (longest setae on about apical half nearly 1.5X as long as femur middle width) and short posteroventral setae. Hind tibia slightly uniformly thickened (lateral view) and somewhat curved (posterior view); with numerous moderately long to long setae dorsally; no seta in posteroapical comb. Hind basitarsus slender; with dorsal setation as on hind tibia, numerous short, spine-like setae ventrally.

Wing membrane hyaline, veins mostly brownish, paler proximally; M 1 beyond cell dm and CuA+CuP (anal vein) very thin, M 2 and M 4 weakened before wing margin; M 1 and CuA+CuP incomplete; cell dm short, with slightly elongate apex. Pterostigma pale yellowish, hardly distinguishable. Basal costal seta present, long, black. Anal lobe well-developed; axillary incision right-angled. Squama brownish, pale fringed. Halter brown.

Abdomen black in ground-colour, uniformly greyish pruinose, mostly covered with numerous pale hair-like setae longer on tergites laterally; sternite 7 with some fine black posteromarginal setae, segment 8 with black setae of different lengths. Segment 8 with separated sclerites; tergite 8 without projections, entire, somewhat concave posteriorly; sternite 8 desclerotized medially.

Terminalia ( Fig. 8 ) moderately large, concolorous with abdomen (except noted), black setose. Epandrium divided into two lamellae (dorsal bridge absent); epandrial lamella subtriangular (lateral view), with rather deep excision closer to base dorsally, with long, fine setae along lateral margins. Hypandrium short, subtriangular (ventral view), with 2 long and 2 short setae. Hypoproct strongly sclerotised, elongate, reaching phallus, narrow on middle part and broadened distally, bare. Phallus brownish yellow, mostly hidden, short, evenly curved, thick on about basal 2/3 and slender on apical 1/3. Ejaculatory apodeme large, extended far beyond basal curvature of phallus, without lateral wings. Cerci closely attached and almost fused anteriorly, separated from epandrium; cercus almost entirely divided in two lobes by narrow notch (lateral view) posteriorly; dorsal lobe rather trapezoid (lateral view), with short, dense, strong setae anteriorly and scattered, fine setae on remaining part; ventral lobe much narrower and slightly longer than dorsal lobe (lateral view), slightly extended beyond epandrial lamella, digitiform, gently curved downwards on about apical half, with some minute setulae.

Female. Unknown.

REMARKS. Empis windhoekiensis sp.n. belongs to the E. (Empis) setitarsus -group [ Daugeron, Grootaert, 2003; Sinclair, Daugeron, 2017]. Within the key to species of this group the new species would run to the couplet 19 joining E. vetula Smith, 1969 and E. cinerarius Daugeron et Grootaert, 2003 [ Daugeron, Grootaert, 2003]. The new species can be readily distinguished from both these species primarily by black setae on the laterotergite. In addition, in the male of E. vetula the phallus is well-exposed, longer, and uniformly slender [ Smith, 1969: 175, fig. 209], whereas in the male of the new species the phallus is short, mostly hidden, thick on about basal 2/3 and slender on apical 1/3. Besides the colour of laterotergal setae, E. windhoekiensis sp.n. differs from E. cinerarius by shorter proboscis (labrum only slightly longer than head height versus labrum about 2X longer than head height), shorter and thicker antennal stylus as well as by the structure of the male hypopygium.

ETYMOLOGY. The name of the new species refers to the type locality, Windhoek.

DISTRIBUTION. Afrotropics: Namibia.

Figures

Figs 7–8. Empis (Empis) windhoekiensis, sp.n., ♂ lateral view: 7 — habitus,; 8 — hypopygium. Abbreviations: cerc d lb — dorsal lobe of cercus; cerc v lb — ventral lobe of cercus; epand — epandrium; hypd — hypandrium; ph — phallus. Рис. 7–8. Empis (Empis) windhoekiensis, sp.n., ♂, сбоку: 7 — габитус; 8 — гипопигий. СокраЩениЯ: cerc d lb — дорсальнаЯ лопасть церка; cerc v lb — вентральнаЯ лопасть церка; epand — Эпандрий; hypd — гипандрий; ph — фаллус.