Dolichopus fuscicercus 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 : 113-117

Dolichopus fuscicercus Pollet, Khaghaninia & Kazerani sp. nov.

( Figs 2–4 , 6 )

Dolichopus plumipes of authors, not Scopoli, 1763: 334. Kazerani et al. 2013: 142; Grichanov 2016: 13.

Diagnosis. Moderate-sized species. Uppermost postoculars black, lower yellow. Antenna largely yellow, with scape and postpedicel partly black. Legs largely yellow, with coxa II and III, apex of tibia III and tarsi largely black. Male: face brilliant pale golden. Cercus rectangular, brown. MSSCs as in D. plumipes ( Scopoli, 1763) : tibia II flattened, with bare dorsal face, mainly white with elongate brown streak along entire length; tarsomere II1 strongly plumose; tibia III with pale pollinosity in basal 1/2 on posterior face, and with ciliolarium and small apical tooth. Wing with strongly undulating posterior margin.

Description. Male. Body length: 3.7–3.8 mm; wing length: 3.6 (n=2). Head. Face brilliant pale golden, slightly narrowing towards clypeus, at clypeus about 0.8 x as wide as postpedicel (length), bare. Frons brilliant metallic green, not dusted. Occiput bronze, not dusted, flat. Palpus about 1/10 of eye, circular, yellow, with dark pubescence and 1 black bristle at apex. Proboscis brown. Eye red, with strong green reflection in frontal view, and with short, dense pubescence. About upper half of postocular bristles black, and lower half golden yellow, uniserial. Two to three pairs of black postocellar bristles. Antenna ( Fig. 2 ) largely yellow, with scape infuscated on dorsal 1/3 along entire length, and postpedicel yellowish white on basoventral 1/3, otherwise black; postpedicel rounded triangular, with rather acute apex, about 1.2 x as long as deep, and 1.3 x as long as scape and pedicel combined; stylus dorsal, inserted at about apical 2/3, rather short, about 1.3 x as long as first three antennal segments combined (2nd article 1.4 x as long as 1st article); 1st article slightly dilated; with microscopic pubescence. Thorax. Entirely bronze to dark metallic green, pleura with greyish dusting; scutellum with 2 strong median, and 2 minute lateral bristles, bare on dorsum. With a group of 2–3 minute white setae in front of posterior spiracle. Main thoracic bristles black. Six dc, with 5th dc medially off-set; 7 ac, biserial, reaching between 4th and 5th dc, as long as distance between rows; with 1 strong and a few minute ant pprn, 1 internal and 1 external bas pprn, 1 psut ial, 1 sut ial, 2 npl, 2 spal, and 1 pal bristles. Upper proepisternum with strong black setae anteriad of anterior spiracle, lower proepisternum with 1 strong black bristle, and many yellow setae. Wing. Hyaline. Costal vein with small cell. Vein M1+2 smoothly bending towards R4+5, both slightly converging towards wing apex; hind margin of wing distinctly undulating (MSSC, similar as in D. plumipes ). Proximal section of M1+2 0.7 x as long as apical section. Proximal section of CuA1 1.4 x as long as apical section. CuA x ratio 2.2. Halter white, calypteral fringe black. Legs. Mainly yellow, with black bristles and pubescence. Coxa I yellow, slightly infuscated laterally on less than basal 1/3; coxa II and III dark metallic green, latter with external bristle inserted at apical 1/ 3 in middle. Trochanters yellow in leg I, brownish yellow in leg II, and mainly brown in leg III. All femora yellow, with only femur III sometimes brownish dorsally. Femur I with 1 small pv preapical bristle; femur II with 1 strong ad preapical and 1 small pv preapical bristles; femur III with 1 strong ad preapical bristle, and one row of about 7 rather erect ds bristles in less than basal 1/3, about 1/ 3 x as long as femur is deep. Tibia I yellow, with 2 ad and 2 ds bristles, with basal bristles inserted beyond basal ¼ and smaller than apical ones, latter about 2 x as long as tibia is deep; with ad serration of short bristles distad of basal ad bristle; with 2 ap bristles on dorsal face; with 3–4 pv bristles, longest about 2 x as long as tibia is wide. Tibia II elongate, strongly flattened, with bare, shining and wrinkled dorsal face; mainly white with yellow basis, with distinct brown streak along entire length (MSSC); with 1 strong basal ad bristle at basal 1/ 10, about 2 x as long as tibia is deep, and 3 minute ad setae; with 1 rather strong pd bristle at basal 1/5, about 1.5 x as long as tibia is deep, and 1 minute pd bristle near apex; with 5 strong ap bristles. Tibia III yellow with apical 1/5 black, with basal 1/2 and apical 1/5 slightly swollen; posterior face with narrow zone of pale pilosity in basal 1/2, and with short white ciliolarium at apex; with small thin apical hook posteroventrally; with 6 ad and 5 pd bristles, basalmost bristles smaller, longest bristles about 3 x as long as tibia is deep, and with 2 ap bristles; with distinct pd pubescence on apical 2/3; ventrally with row of multiple, thin rather erect bristles on basal 1/2, and 1 strong av bristle at apical 1/3, about 1.5 x as long as tibia is wide. Tarsus I yellow, black from apical 1/5 of taI1 onwards. Tarsus II ( Fig. 2 ) entirely black, with taII1 strongly flattened dorsoventrally, with anterior and posterior row of distinctly flattened black bristles (plumose character) (MSSC). Tarsus III entirely black, taIII1 with 2 strong ds and 1 ad bristle, and 4 smaller ventral bristles. Length ratios of femur/tibia/tarsomeres 1–5 in leg I: 6.7/6.8/3.5/1.7/1.4/ 1/1, in leg II: 8.1/10.3/3/1.7/1.4/1/1, and in leg III: 7.3/9.1/3.9/3/2.1/1.2/1. Abdomen. With 5 pubescent tergites, T6 bare, largely covered by T5. Tergites and S2 concolorous with thorax, with black bristles. S3 rudimentary and S4-5 white, forming enclosure for hypopygium, with sparse minute pale pubescence. Hypopygium ( Figs 3–4 , 6 ) with epandrium bronze to dark metallic green; hypandrium blackish brown, short, straight; phallus reddish yellow, narrow, rather straight; left bv epandrial lobe distinctly stronger than right lobe, hook-like; apv epandrial lobe rather quadrate, dark brown, with two pale setae; cercus moderate-sized, rectangular, brown with strong curved bristles on tubercles on apical margin. Female. Body length: 4.1 mm; wing length: 3.7 mm (n=1). As male, except for the following features: face greyish, at clypeus about 1.4 x as wide as postpedicel is long, with clypeus slightly bulging. Antenna with postpedicel about as long as deep, and 0.9 x as long as scape and pedicel combined; stylus rather short, about 1.4 x as long as long as first three antennal segments combined (2nd aristomere 2.4 x as long as 1st aristomere). Wing without undulating posterior margin. Proximal section of M1+2 0.9 x as long as apical section. Proximal section of CuA1 1.6 x as long as apical section. CuA x ratio: 2.0. Abdomen with T6 entirely covered by T5; sternites dark metallic green with short dense black pubescence. Legs with coxa I yellow, slightly infuscated on basal 1/2, mainly laterally. Femur I with 1–2 small pv preapical bristles; femur III without small preapical bristles. Tibia I with 2 pv bristles, longest about 1.5 x as long as tibia is wide, sometimes with 1 small av bristle; tibia II brownish yellow with extreme apex black, with 4 strong ad and 2 strong pd bristles, basal bristles inserted at basal 1/5; with 1 av bristle at apical 1/3, all bristles on tibia II about 3 x as long as tibia is wide; tibia III yellow, gradually darker towards apex, with apical 1/3 black; sometimes with one additional small av bristle. Tarsus I yellow at extreme basis, gradually darker towards apex, with apical 1/4 black; tarsus II entirely black, all tarsomeres with short inclined ventral bristles along entire length. Length ratios of femur/tibia/tarsomeres 1–5 in leg I: 8/8/3.8/1.8/ 1.3/1/1.2, in leg II: 7.8/9.2/4/2.1/1.5/1/1, and in leg III: 7/8.8/3.1/2.9/2/1.3/1.

Type material. HOLOTYPE ♂, IRAN: East Azerbaijan, Arasbaran , Chichekli (forest), 38°30.437′N, 46°36.447′E, 1724 m, 25.vi.2013, SW, leg. Samad Khaghaninia ( ICHMM) . PARATYPES: IRAN: 1♀, same data as holotype ; 4♂, 2♀, East Azerbaijan, Kandovan (grassland), 37°44.200′N, 46°18.001′E, 3090 m, 28.vii.2014, SW, leg. S. Khaghaninia ( ICHMM) ; 3♂, 3♀, East Azerbaijan, Kandovan (grassland), 37°44.001′N, 46°19.010′E, 3000 m, 28.vii.2014, SW, leg. S. Khaghaninia ( TMUC) ; 2♂, same data ( MAPC) ; 5♂, 4♀, East Azerbaijan, Kandovan (grassland), 37°46.10′N, 46°16.001′E, 2500 m, 15.vi.2013, SW, leg. S. Khaghaninia ( ICHMM) ; 6♂, 3♀, East Azerbaijan, Kandovan (grassland), 37°44.254′N, 46°19.256′E, 3005 m, 6.vii.2013, SW, leg. S. Khaghaninia ( ICHMM) ; 1♂, East Azerbaijan, Arasbaran , Keleybar (forest), 38°51.548′N, 46°59.007′E, 1783 m, 1.vii.2013, SW, leg. S. Khaghaninia ( MAPC) (latter record, see also Kazerani et al. 2013).

Distribution and ecology. Thus far, the species has only been encountered in the East Azerbaijan province of Iran. It has been collected both in grasslands between 2500 m and 3090 m and forest habitats below 1800 m, but in fair numbers only in grasslands, a habitat also preferred by D. plumipes . In fact, previously D. fuscicercus sp. nov. was erroneously recorded as D. plumipes from Iran by Kazerani et al. (2013).

Etymology. The species name “ fuscicercus ” refers to the uniformly brown cercus ( Figs 2–4 , 6 ), which is only found in a few Dolichopus species (e.g., D. apicalis Zetterstedt, 1849 and D. campestris Meigen, 1824 ), whereas most species feature a white cercus with a dark margin ( Fig. 5 ).

Remarks. Dolichopus fuscicercus clearly belongs to the D. plumipes species group (Germann et al. 2010; Pollet et al. 2010; Khaghaninia et al. 2013b), and features two MSSCs that are found in other species of this group: the undulating posterior wing margin and the plumose mid tarsus. It differs from two other Palaearctic species with a plumose mid tarsus, D. polleti Meuffels & Grootaert, 1989 and D. wahlbergi Zetterstedt, 1843 by the presence of a brown streak on the mid tibia, and the hind tibia with a dark apex (entirely pale in both other species). Dolichopus plumipes is mainly Holarctic in distribution, with extensions into the Neotropics and Oriental realms. MP has examined D. plumipes from all over Europe and Canada, and checked pictures of D. plumipes from China (Sichuan; Xizang (Tibet )). None shared the hypopygial features found in D. fuscicercus . Sequencing with COI barcodes and/or other markers could provide evidence on the identity and relationship of D. fuscicercus with D. plumipes , but this has not been possible thus far. Dolichopus fuscicercus can be most easily distinguished from the third species with a plumose mid tarsus, D. plumipes , as follows:

1 Smaller species (male body length less than 4.0 mm). Cercus rather rectangular and uniformly brown; apicoventral epandrial lobe dark brown ( Fig. 3 ). Postpedicel of antenna rounded triangular, 1.2 x as long as deep. Hind tibia pale yellow with apical 1/ 5 black............................................................... Dolichopus fuscicercus sp. nov. ( Iran)

- Larger species (male body length more than 4.0 mm). Cercus ovoid, white with black margin; apicoventral epandrial lobe pale yellow ( Fig. 5 ). Postpedicel of antenna rather ovoid, 1.7 x as long as deep. Hind tibia pale yellow with at most apical 1/8 black....................................................... Dolichopus plumipes (Holarctic, Mexico, Oriental China)

Figures

FIGURE 6. Dolichopus fuscicercus sp. nov., male, hypopygium (scale 0.5 mm) and appendages (scale 0.1 mm). Abbreviations: apv lobe: apicoventral epandrial lobe, bv lobe: basoventral epandrial lobe, cerc: cercus, dsur: dorsal surstylar lobe, hyp: hypandrium, ph: phallus, vsur: ventral surstylar lobe.

FIGURES 2 – 5. Dolichopus fuscicercus sp. nov., male: (2) habitus; (3) hypopygium; (4) cercus. Dolichopus plumipes, male: (5) hypopygium.