Rhamphomyia (Dasyrhamphomyia) leptidiformis Frey

Rhamphomyia (Dasyrhamphomyia) leptidiformis Frey

(Figs 11–13)

Rhamphomyia (Dasyrhamphomyia) leptidiformis Frey, 1950: 108. Type-locality: “Verhojansk” [= Verkhoyansk, 67°33′N 133°23′E], Yakutia, Russia. Other references: Frey, 1955b: 517 (revision).

R. (Rhamphomyia) leptidiformis: Chvála & Wagner, 1989: 287; Shamshev, 2001: 330 (key); Yang et al., 2007: 184 (catalogue); Shamshev, 2016: 78 (checklist).

Type material examined. LECTOTYPE (here designated in order to fix identity of the species) ♂ (Fig. 11A), labelled (Fig. 11B): “[printed in Cyrillic, Russian] Verkhoyansk [67°33′N 133°23′E],/ Yakutsk. obl. [= Yakutskaya oblast’, now Sakha (Yakutia) Republic] [1]903/ Rożnowski [full name Kazimierz Rożnowski] VI. [=June]; “pink square label with unclear hand-writing”; “Spec. typ. [pink, printed]”; “ Rh. leptidiformis / Frey Type [hand-written by Frey] Frey det. [printed]”; “ris. Bazanova/ 1976 [hand-written in Cyrillic, = fig. of Bazanov]”; “ Syntypus [red label]”; “ LECTOTYPUS / Rhamphomyia leptidiformis / Frey, 1950 / design. Shamshev, 2017 [red label]” (ZIN, INS _DIP_0000526). PARALECTOTYPES: same locality data as lectotype (1 ♀, MZH; 2 ♀, ZIN).

Additional material examined. CANADA. Northwest Territories: Aklavik, 26.vi.–8.vii.1931, Bryant (1 ♂, 2 ♀, CNC); Saw Mill Bay, 21–23.vi.1948, D.F. Hardwick (2 ♀, CNC). Nunavut: Bathurst, 17.vii.1951, C.D. Bird (1 ♀, CNC); Coppermine, 24.vii.1951, S.D. Hicks (1 ♂, CNC); Cambridge Bay, 69.11993°, -105.4065° [Repl.1], 69.12070°, -105.42582° [Repl.2], 69.12157°, -105.43124° [Repl.3], 7–19.vii.2011, mesic, MT, NBP field party (8 ♂, LEM); Cambridge Bay, 69.12157°, -105.43124°, Repl. 3, 15–19.vii.2011, mesic, MT, NBP field party, CCDB- 21421-G07, CCDB-21421-G10 (2 ♀, barcode associated, LEM); Kugluktuk, 67.77436°, -115.30732°, 7–12.vii.2010, mesic, MT, Repl. 3, NBP field party (37 ♂, LEM); same data except, CCDB-21421-C03 (1 ♂, barcoded, LEM); Kugluktuk, 67.77436°, -115.30732°, 26.vii.–2.viii.2010, mesic, MT, Repl. 3, NBP field party, CCDB-21421-E010 (1 ♀, barcode associated, LEM); Kugluktuk, 67.83538°, -115.20987°, 3–7.vii.2010, mesic, MT, Repl. 3, NBP field party, CCDB-21421-E04 (1 ♀, barcode associated, LEM); Muskox Lk., 64°45′N, 108°10′W, 18.vii.–2.viii.1953, J.G. Chillcott, (1 ♂, 6 ♀ CNC); Padley [Padlei], 24–27.vii.1950, R. E. Duckworth (1 ♂, 1 ♀, CNC). Yukon: Dempster Hwy, mi 141, 22–24.vi.1982, G. & M. Wood (1 ♂, CNC); Dempster Hwy, mi 155, 950 m, 11–12.vii.1981, D. Lafontaine, G. & M. Wood (1 ♂, CNC); Firth River, 14.vii.1956, R. E. Leach (1 ♀, CNC); Ross River, 61°56′N 132°30′W, 3000 ft, 21.vi.1960, J.E.H. Martin (1 ♀, CNC). USA. Alaska: Fairbanks, Creamer’s Field, 148 m el, 64.87515° -147.68938°, spruce, birch, hanging MT, 31.v.–14.vi.2016, J. Hagelin (1 ♂, UAM).

Diagnosis. This species is distinguished from other Dasyrhamphomyia by three distinctive brown vittae beneath acrostichal and dorsocentral rows, legs reddish-brown, contrasting with greyish thorax, male left cercus folded over right at apex, reaching anterior margin of tergite 5 or hind margin of tergite 4, tip of cercus dark, and hind tibia with anteroventral row of dark, spine-like setae shorter than half tibial width.

Redescription. Wing length 5.4–6.7 mm. Male. Head dark in ground-colour, with dense greyish pruinescence on face, frons and occiput. Clypeus yellow-brown. Holoptic; eye with ommatidia larger on upper half, smaller on lower half. Frons represented by very small triangular space below ocellar tubercle and larger subtriangular space above antennae, bare. Face slightly divergent towards mouthparts, bare, with oral margin dark and shiny. Ocellar triangle dark grey-blue, with 1 pair of parallel setae, 1 pair of shorter, finer posterior setae and 2–3 pairs of short, fine postocellar setae. Occiput bearing row of stout, short, dark postocular setae on upper half; setae of upper half similar to postocular setae; setae of lower occiput longer; postgena bearing finer, longer setae than occipitals. Pedicel and scape reddish brown; postpedicel and stylus dark; scape less than 2X longer than pedicel; postpedicel cone-shaped, about 2X longer than basal width; stylus subequal to basal width of postpedicel. Palpus short, subequal to length of scape and pedicel combined; palpus pollinose and light brown, with dark, fine setulae. Clypeus with greyish pruinescence; labrum reddish-brown and lustrous; apex of labrum pale; proboscis largely pale grey, slightly longer than head height; labellum with dark setae.

Thorax dark with dense grey pruinescence. Scutum with pair of distinct subshiny greyish vittae between acr and dc rows, separated by broad brown stripes beneath acr and dc rows; postalar ridge pale brown. Proepisternum with short, dark setae; prosternum bare; upper part of proepisternum in front of anterior spiracle bare. Antepronotum with row of short, stout dark setae. Postpronotal lobe with 1 pprn and several shorter setae anteriorly. Scutum with biserial short acr; uniserial dc longer than acr, increasing in length posteriorly; 2 presut spal setae (posthumeral) and several shorter setae; 2–3 npl setae with numerous setulae anteriorly; 2–4 short prealar setae; 2 psut spal; 1 pal; 1 pair of long apical and 1 pair of short lateral sctl. Laterotergite with numerous fine, long, dark setae. Anterior and posterior spiracles pale brown.

Legs reddish-brown; coxae with greyish pruinescence. Hind and mid coxae with a few short, dark lateral setae; fore coxa with several dark anterior setae, longer than lateral setae of mid and hind coxae. Femora with whitish ven- tral pile, with 1 anteroventral and 1 posteroventral row of dark setae, stronger on mid and hind femora (Fig. 12A). Fore tibia clothed with short, fine dark setae. Mid tibia with anteroventral and posteroventral rows of strong setae. Hind tibia (Fig. 12A) with anteroventral row of dark spine-like setae, shorter than ¼ of tibial width, absent on proximal ¼ of tibia; anterodorsal and posterodorsal rows of setae increasing in length apically, ending in pair of stronger preapical setae; 1 long seta in posteroapical comb. Hind tarsomere 1 with short, dark, spine-like setae beneath.

Wing lightly infuscate; all veins complete (except Sc), well sclerotized. Basal costal seta absent; pterostigma present. Anal lobe well-developed; axillary incision forming right angle. Halter yellowish white.

Abdomen light brown with distinct pale posterior margins of each tergite and sternite. Abdomen covered in dark, fine, short setae, longer on tergites laterally and in middle of sternites. Sternite 8 triangular, bearing dark, fine marginal setae, shorter than length of sclerite. Tergite 8 with distinct marginal setae, longer than length of sclerite; length of tergite 8 one half length of sternite 8.

Terminalia (Figs 12B, C) with epandrium swollen, oval, with stout, rounded, finger-like projection, bearing many short, stout, dark, peg-like setae as well as many finer, longer setae. Hypandrium short, cylindrical, partly membranous, partly well-sclerotized, lustrous and yellow-brown, hugging base of phallus. Phallus lustrous yellowbrown; smoothly arched with subapical bend; apical portion of phallus slender, bearing 2 short, teeth-like subapical projections. Cercus pale with darkened apex and base (Fig. 12B); cercus elongated, directed anteriorly over abdomen, reaching tergite 5 or hind margin of tergite 4; left cercus overlapping right at apex in dried specimens; inner margins of cercus with fine setae; base of cercus with pair of dorsally projected lobes, anteriorly lobe short and bare, posterior lobe 3X longer with fine marginal setae. Ejaculatory apodeme small, with lateral wings of equal length to vertical wing.

Female. Similar to male, except wings broader and darker, lacking modified leg setae; without pennate leg setae.

Distribution. In North America, this western-central southern arctic species (Danks 1981, figs 62, 63) ranges from Hudson Bay to Alaska, primarily in low arctic areas (Fig. 13). In the Palaearctic Region, this species is known from Eastern Siberia, Russia (Shamshev 2016).