Rhamphomyia (Pararhamphomyia) septentrionalis Sinclair, Vajda, Saigusa & Shamshev 2019, sp. nov.

Rhamphomyia (Pararhamphomyia) septentrionalis Sinclair, Vajda, Saigusa & Shamshev sp. nov.

(Figs 44, 45)

urn:lsid:zoobank.org:act: A644129B-1C81-4F23-AD19-2B0681059818

Type material. HOLOTYPE ♂, labelled: “Victoria Is., N.W. T. [Northwest Territories, Canada]/ 71°17′N, 114°W / 23–28.VII.1975, G. & M. Wood ”; “ HOLOTYPE / Rhamphomyia / (Pararhamphomyia)/ septentrionalis Sinclair, Vajda,/ Saigusa & Shamshev [red label]” (CNC). PARATYPES: CANADA. Northwest Territories: Same data as holotype (18 ♂, 9 ♀, CNC; 1 ♂, 1 ♀, ZIN); Aklavik, 26–29.vi.1956, R. E. Leech (3 ♂, 2 ♀, CNC); Aklavik, 29.vi.1956, E.F. Cashman (1 ♀, CNC); Aklavik, 16.vi.1953, C.D. Bird (1 ♂, CNC); Banks Is., Masik River, 17– 27.vii.1968, G.E. Shewell, W. R. M. Mason (3 ♂, 1 ♀, CNC); Fort McPherson, 12.vii.1957, R. Hurley (1 ♂, CNC). Nunavut: Bylot Island, Cone 9, 73.165°N 79.845°W, 2.vii.2015; ex. willows, M. Tremblay (3 ♀, CNC), same, Fond Valley, 73.180°N 79.133°W, 1.vii.2015 (1 ♂, 2 ♀, CNC); same, Luticone 73.155°N 79.922°W, 20.vi.2015 (1 ♀, CNC); Tuktoyaktuk, 69°26′40.02″N 133°1′55.74″W, sweeping meadow, 14.vii.2010, Goulet & Boudreault (1 ♂, CNC). Yukon: mi 87 Dempster Hwy, 1–17.vii.1973, G. & M. Wood (4 ♂, 7 ♀, CNC); North Fork Crossing, mi 43 Peel Plateau Rd., 3500 ft, 4–26.vii.1962, R. E. Leech (1 ♂, 6 ♀, CNC); Dempster Hwy nr North Fork Pass, 64.60629°, -138.35637°, 1170 m, wet, MT, Repl. 1, 21–24.vi.2011, NBP Field Party, CCBD-21421-A05 (1 ♂, bar- coded, LEM), same data except, 21–24.vii.2011, CCBD-21421-A04 (1 ♂, barcoded, LEM). USA. Alaska: 25 mi N Gakona, 18.vi.1988, D.M. Wood (2 ♂, CNC); Isabel Pass, mi 206 Richardson Hwy, 2900 ft, 13.vii.1962, R. E. Leech (3 ♂, CNC); 4 mi N Nome, Anvil Mt., 4.vii.1993, T. Saigusa (2 ♂, KUMF); Nome, Bourbon Ck, bog, 21.vi.1994, T. Saigusa (1 ♂, KUMF); Nome area, mi 55 Kougarok Rd, 65°05′23″N 164°40′20″W, MT, 20–28.vi.2005, J. & R. Skevington (4 ♂, CNC); mi 213 Richardson Hwy, 17.vi.1951, W. R. M. Mason, J. R. McGillis (2 ♂, CNC); Umlat, 4–16.vii.1959, J.E.H. Martin (3 ♂, 14 ♀, CNC).

Additional material examined. Russia. Krasnoyarskiy Territory: Dudinka, Wuorentaus, 1295 (1 ♂, MZH). Nenets Autonomous okrug: Kanin, B. Poppius (1 ♂, MZH).

Diagnosis. This species is distinguished by the two pairs of shiny scutal vittae, the elongate, spindle-shaped male hind tarsomere 1, more than half the length of the tibia, with long setae dorsally, 2X tarsal width, hind tibia with distinctive inward bend, and the female wing is brownish, broadly rounded.

Description. Wing length 5.4–6.1 mm. Male. Head dark in ground-colour, with greyish pruinescence on face, frons, occiput and postgena. 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 brownish-black and shiny. Ocellar triangle dark, subshiny, with 1 anterior pair of long setae and 1 shorter posterior pair of finer setae; 2 pairs of short, fine postocellar setae. Occiput bearing row of postocular setae, fine, only present on upper section, remaining setae long and fine; postgenal setae hair-like, long and pale. Antenna dark, densely grey pubescent, with brownish tinge on pedicel. Scape 2X longer than pedicel; pedicel broader than scape; pedicel bulbous; postpedicel nearly 3X longer than basal width; stylus shorter than scape, thin and cone-like. Palpus dark, densely pubescent, with setulae long, dark and fine. Clypeus pruinescent; labrum lustrous and dark reddish brown, long than head height; labellum grey with dark setae.

Thorax dark brownish to black in ground-colour, with grey pruinescence. Scutum with 2 distinct glossy vittae between acr and dc rows, and broad vitta along supra-alar region. Proepisternum with several long, pale setae on lower section; upper proepisternum in front of spiracle bare; prosternum bare. Antepronotum with row of short, stout, pale golden setae. Postpronotum with several fine, hair-like, pale setae and 1 thicker pprn. Scutum with biserial sparse, fine, short pale acr; dc similar to acr, except only slightly longer, with prescutellar dc stouter, darker and long; notopleuron with dense anterior cluster of fine, pale setae, slightly longer than postpronotal setae, 3 stouter, longer, pale setae posteriorly; sparse row of fine, short, pale presut spal; 0 prealar setae; several psut spal; 1 pal and short setulae; 3–5 pairs of sctl. Laterotergite with cluster of pale setae. Anterior and posterior spiracles dark.

Legs entirely dark brown, shiny; coxae with grey pruinescence. Coxae mostly covered with simple pale setae. Femora with white ventral pile. Fore femur sparsely setose, with 1 anteroventral and 1 posteroventral row of fine, short setae. Mid femur with row of stiff anteroventral setae, decreasing in length apically; row of stout posteroventral setae, some setae at mid-length longer than width of femur. Hind femur slender basally, with row of anteroventral pale setae, increasing in length and density apically, shorter than width of femur (Fig. 44B). Fore tibia with ventral and posterior regions clothed with many fine, short setae; preapical circlet with 3 anterior setae stouter. Mid tibia with rows of stout anteroventral and posteroventral setae, shorter than or subequal to tibial width; anterior region clothed with many fine, short setae. Hind tibia with basal inward bend and slightly thinned and compressed (Fig. 44B); posterodorsal setae fine, 2X tibial length; row of erect posteroventral setulae; 1 long seta in posteroapical comb. Hind tarsomere 1 spindle-shaped, longer than half length of tibia (Fig. 44B), covered with long setae dorsally, 3X as long as tarsal width; posterior face flattened, clothed with many short, fine pale setulae; tarsomeres 2–4 broader than corresponding mid and fore tarsomeres, with long setae dorsally. Fore and mid tarsi with white ventral pile.

Wing lightly infuscate with yellowish veins; all veins complete (except Sc) and well sclerotized, except CuA+CuP near wing margin. Anal lobe well-developed; axillary excision right angled. Costa without basal seta; pterostigma present, dark. Halter mostly yellowish white, with darkened stem base.

Abdomen glossy, mostly dark brown, although sternites more blackish, margins of segments pale; clothed in long, fine pale setae. Sternite 8 rectangular in lateral view, with weakened ventral face; marginal setae longer than length of sclerite; closely approximated dorsally with tergite 8. Tergite 8 held upright, with shallow constriction in middle; half length of sternite 8; marginal setae short and hair-like.

Terminalia (Figs 44A, C) elongate, longer than thorax; dark, apical half of cercus and epandrium paler. Epandrium elongate, middle region constricted; apical half expanded, with broadly rounded apex, curving inwards, then curving outwards away from opposite lamella; lamella bearing many pale, fine, short and longer setae. Cercus slimmer and shorter than epandrium; constricted at mid-length; apical half slightly tapered and curved, with flaplike inner setose lobe; dorsal margin of proximal half with row of fine setae. Hypandrium short, slim, rectangular, ending at start of swollen phallus. Phallus hair-like, without loops, extending beyond epandrium and arching back; ejaculatory apodeme small, acutely fan-shaped, lateral wings slightly shorter than vertical wing.

Female. Similar to male, except wing broad, somewhat oval, darkly infuscate (Fig. 44D); hind tarsomere 1 slightly swollen, not spindle-shaped; leg chaetotaxy reduced, without pennate setae.

Distribution. This species occurs in the low arctic west of Hudson Bay in North America (Fig. 45) and northern regions of Russia.

Etymology. The specific name is from the Latin septentrionalis (north, northern), in reference to the distribution of this species.

Remarks. Rhamphomyia septentrionalis sp. nov. is assigned to the R. caudata group (see Remarks section under R. filicauda). We compared this new species with a male type specimen of R. tenuiterfilata Becker. The hind tarsomere in R. tenuiterfilata is shorter and more rounded and broader subapically with setae as long as the width of the segment, whereas it is longer and broader at mid-length and tapered apically with setae twice the width of the segment in R. septentrionalis sp. nov. The male cerci in R. tenuiterfilata are broader on the anterior half, with strong dorsal setae at mid-length, while the cerci are rather slender throughout in R. septentrionalis sp. nov.