Gymnopternus atratus Pollet, Khaghaninia & Kazerani

Kazerani, Farzaneh, Khaghaninia, Samad, Talebi, Ali Asghar, Persson, Magnus & Pollet, Marc, 2017, Eight new species of Dolichopodinae (Diptera: Dolichopodidae) from northern Iran, Zootaxa 4242 (1), pp. 111-141 : 119-122

Gymnopternus atratus Pollet, Khaghaninia & Kazerani sp. nov.

( Figs 12–14 )

Diagnosis. Male. Rather small robust dark species. Face greyish white. All postocular bristles black. Antenna entirely black with postpedicel as long as deep, triangular with rather acute apex. Wing slightly infuscate. Legs including coxae and trochanters entirely black except for extreme apex of femur I–III. Hypopygium rather robust with dark appendages; cercus black, club-shaped and relatively narrow. Distinct MSSCs lacking.

Description. Male. Body length: 2.8 mm; wing length: 2.9 mm (n=1). Head. Face greyish white, slightly narrowing below antenna, at middle parallel-sided; epistoma with shallow central furrow, at clypeus 0.7 x as wide as postpedicel is long; clypeus retracted, bare. Frons dark metallic green, only slightly dusted. Occiput dark metallic green, rather convex. Palpus very small, less than 1/10 of eye, circular, black, with dark pubescence and 1 black apical bristle. Proboscis brown. Eyes red, with green reflection in frontal view, with short dense pubescence. All postocular bristles black. Three pairs of black postocellar bristles. Antenna entirely black, with postpedicel triangular, as long as deep and 1.2 x as long as scape and pedicel combined (pedicel overlapping dorsal edge of postpedicel), with rather acute apex; stylus dorsal, inserted at about apical 1/3, rather short, about 1.5 x as long as first three antennal segments combined, with microscopic pubescence. Thorax. Entirely dark metallic green, pleura dusted greyish; scutellum with 2 strong median, 2 minute lateral bristles and a dense black pubescence on disk and margin. A group of 3–4 short setae in front of posterior spiracle. Thoracic bristles black. Six dc, with 5th dc medially off-set; about 10–12 ac, biserial, reaching 6th dc, there with additional ac-sized bristles laterad of ac rows, ac about 1.5 x as long as distance between rows; 1 strong and a few minute ant pprn, 1 internal and 1 external bas pprn, 1 psut ial, 1 equal-sized sut ial, 2 npl, 2 spal, and 1 pal bristles. Upper proepisternum with a few black setae, lower proepisternum with 1 strong black bristle, with many black setae. Wing. Slightly infuscate. Vein R4+5 slightly curved, M1+2 rather straight, both slightly converging towards wing apex, parallel at apex. Proximal section of M1+2 0.9 x as long as apical section. Proximal section of CuA1 1.8 x as long as apical section. CuA x ratio: 1.8. Halter white, calypteral fringe black. Legs. Nearly entirely blackish brown, including coxae and trochanters, except for extreme apex of femur I–III. Bristles black. Coxa III with 1 strong external bristle, inserted at about centre. Femur I with extreme apex brownish, and with 3 small pv preapical bristles; femur II with extreme apex yellowish, with 1 strong ad and 1 smaller pv preapical bristles; with one av and one pv row of short indistinct inclined bristles along entire length; femur III with extreme apex yellowish; with 1 strong ad bristle at about apical ¼, and with one row of about 6 rather erect ds bristles on basal 1/3, less than 1/3 as long as femur is deep. Tibia I with extreme basis brownish, with 1 ad bristle at basal 1/3 and ad serration of black bristles on apical 2/3, about as long as tibia is deep; with 2 ds (or pd) bristles, at basal 1/3 and 1/2, longest one 2 x as long as tibia is deep. Tibia II with extreme basis brownish, with 3 strong ad and 2 strong pd bristles, between 2.5– 3 x as long as tibia is deep, with basal bristle pair inserted at basal 1/5; with 1 av bristle at apical 2/5, about 3 x as long as tibia is deep; with 5 (4 large, 1 small) ap bristles. Tibia III blackish brown, with apical tooth on posterior face, articulating with small hook on taIII1; with 3 ad and 3 pd bristles, about 2.5– 3 x as long as tibia is deep; with pd serration on less than apical 2/5, and 3 large ap bristles, incl. one preapical ad bristle; with rather distinct pd row of bristles, especially on apical 2/3; with 1 ventral bristle at apical 1/3, about 2 x as long as tibia is deep. All tarsi black; taIII1 with some strong ventral bristles, about as long as taIII1 is deep; with small hook at extreme basis on posterior face. Length ratios of femur/tibia/tarsomeres 1–5 in leg I: 8.5/8.8/4.5/1.5/1.3/1/1.3, in leg II: 7.8/8.8/3.9/1.9/1.4/1/1.1, and in leg III: 2.9/3.4/1/1.1/-/-/- (tarsomeres III3-5 lacking). Abdomen. With 5 pubescent tergites, T6 bare, visible, about 0.6 x as long as T5. Tergites and S2 dark metallic green, with black bristles. S3 rudimentary and S4-5 white, forming enclosure for hypopygium, with dense, black pubescence. Hypopygium rather robust, with blackish brown, straight hypandrium, parallel-sided in ventral view; apicoventral epandrial lobe ( Fig. 14 ) blackish brown with paler basis and triangular process near basis; cercus black, club-shaped and rather narrow, with apical margin nearly straight; apical and ventral margin with dark bristles. Female. Unknown.

Type material. HOLOTYPE ♂, IRAN: West Azerbaijan, Khoy (montane grassland), 38°34.220′N, 44°50.896′E, 1305 m, 10.vi.2014, SW, leg. Samad Khaghaninia ( ICHMM).

Distribution and ecology. The holotype is the only representative of this species (see above).

Etymology. The species name “ atratus ” refers to the overall dark coloration of the species.

Remarks. Only two of the 10 European Gymnopternus species ( Pollet 1990; Pollet & Rampazzi 2003) have black femora, namely G. cupreus (Fallén, 1823) and G. angustifrons . In the key by Pollet (1990), both G. flavitibia Pollet, Khaghaninia & Kazerani sp. nov. and G. atratus sp. nov. would run to G. angustifrons , an equal-sized species with the same coloration as G. flavitibia . The three species can be separated as follows (none of the other dark-legged Palaearctic and Chinese Gymnopternus species proved conspecific to either of the new species, based on the shape of the hypopygial appendages):

Males

1 Legs ( Fig. 12 ) entirely black. Cercus ( Fig. 13 ) entirely black, rather narrow, about 1.5x as long as wide at middle........................................................................................... G. atratus sp. nov. ( Iran)

- Tibia I and II nearly entirely yellow, tibia III distinctly infuscate at apex. Cercus wider, about as long as deep........... 2

2 Postpedicel subcircular. All tibiae ( Fig. 15 ) with extreme base distinctly infuscate. Hypopygium ( Fig. 17 ) larger and more robust, ovoid. Hypandrium ( Fig. 18 ) longer, slightly tapering and truncated at apex in ventral view. Apicoventral epandrial lobe stouter, dark brown with white basis, and short, more abrupt apical bend. Cercus black, club-shaped, with distinct apical indentation............................................................ Gymnopternus flavitibia sp. nov. ( Iran)

- Postpedicel ovoid. Tibiae with pale base, at most slightly infuscate in tibia III. Hypopygium smaller, with epandrium rather quadrate. Hypandrium ( Fig. 19 ) rather short, tapering towards apex in ventral view. Apicoventral epandrial lobe rather long and slender, brownish yellow with white basis, bending gently at apex. Cercus dark brown, roundish club-shaped, with hardly any indentation in apical margin........... Gymnopternus angustifrons (Palaearctic, incl. eastern Russia and Kazakhstan)

Females

1 Clypeus entirely bare. All tibiae with extreme base distinctly infuscate............ Gymnopternus flavitibia sp. nov. ( Iran)

- Clypeus with dense black pubescence. Tibiae with pale bases, at most slightly infuscate in tibiae III.............................................. Gymnopternus angustifrons ( Staeger, 1842) (Palaearctic, incl. eastern Russia and Kazakhstan)

Figures

FIGURE 14. Gymnopternus atratus sp. nov., holotype, hypopygium (scale 0.5 mm) and hypopygial appendages (scale 0.1 mm). Abbreviations: apv lobe: apicoventral epandrial lobe, cerc: cercus, dsur: dorsal surstylar lobe, hyp: hypandrium.

FIGURES 12 – 13. Gymnopternus atratus sp. nov., holotype. (12) habitus; (13) hypopygium (scale 0.5 mm).

FIGURES 15 – 17. Gymnopternus flavitibia sp. nov., male. (15) habitus: (16) antenna: (17) hypopygium.

FIGURES 18 – 19. Gymnopternus flavitibia sp. nov., male: (18) hypopygial appendages (scale 0.1 mm). Gymnopternus angustifrons: (19) hypopygial appendages (scale 0.1 mm). Abbreviations: apv lobe: apicoventral epandrial lobe, cerc: cercus, dsur: dorsal surstylar lobe, hyp: hypandrium, vsur: ventral surstylar lobe.