Rhamphomyia (Pararhamphomyia) frigida Sinclair, Vajda, Saigusa & Shamshev, 2019

Sinclair, Bradley J., Vajda, Élodie A., Saigusa, Toyohei, Shamshev, Igor V. & Wheeler, Terry A., 2019, Rhamphomyia Meigen of the Canadian Arctic Archipelago, Greenland and Iceland (Diptera: Empididae), Zootaxa 4670 (1), pp. 1-94 : 40-43

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

( Figs 25 , 26 )

urn:lsid:zoobank.org:act:199A8094-8B4A-45CD-8453-30ACBF0297A8

Type material. HOLOTYPE ♂, labelled: “Herschel Is. Y. T. [Yukon Territory, Canada ]/ 11.VII.1953 / C. D. Bird ”; “ HOLOTYPE / Rhamphomyia / (Pararhamphomyia) frigida / Sinclair, Vajda, Saigusa &/ Shamshev [red label]” ( CNC) . PARATYPES: CANADA. Northwest Territories: Tuktoyaktuk , 15.vii.1971, D.M. Wood (1 ♂, CNC); same locality, 69°26′16.20″N 133°1′2.16″W, pan trap, meadow, 15–18.vii.2010, Goulet & Boudreault (1 ♂, 1 ♀, CNC); same locality, 69°26′40.02″N 133°1′55.74″W, sweeping, meadow, 14.vii.2010, Goulet & Boudrealt (1 ♂, 1 ♀, CNC) . Yukon: Same data as holotype, 9–23.vii.1953 (18 ♂, 29 ♀, CNC; 1 ♀, ZIN); Herschel Is., 11–26.vii.1953, J.S. Waterhouse (10 ♂, 8 ♀, CNC; 1 ♂, ZIN) . USA. Alaska: St. Paul Island [Pribilof Islands] [not shown on Fig. 28 ], 15.viii.1897 (2 ♂, USNM) .

Diagnosis. This dark-legged and dark setose species is distinguished from other Pararhamphomyia by long, strong coxal setae, male hind tibia with anterodorsal and posterodorsal setae longer than 2X tibial width on apical 2/3, epandrium prolonged apically into short, finger-like projection, phallus extending beyond epandrium, without loops and simple subepandrial lobes.

Description. Wing length 4.2–5.0 mm. Male. Head dark in ground-colour, with greyish pruinescence on face, frons and occiput. Holoptic, eye with ommatidia larger on upper half and smaller on lower half. Frons represented by very small triangular space below ocellar tubercle and larger subtriangular space above antennae, bare; face short, almost parallel, although slightly divergent towards mouthparts; bare, with oral margin dark and shiny. Ocellar triangle dark, with 1 anterior pair of dark, parallel setae and 1 pair of shorter posterior setae; 2 pairs of dark postocellar setae, no longer than posterior ocellar setae. Occiput bearing row of dark, curved postocular setae only on upper half of occiput; clothed with black, stout setae, shorter than postoculars. Postgena bearing dark setae longer and more hair-like than occipital setae. Antenna dark and pruinose; scape slightly longer than pedicel; pedicel bulbous and wider than scape; postpedicel nearly 3X longer than basal width; stylus no longer than basal width of postpedicel. Palpus dark and pollinose, with setulae dark. Clypeus large with shiny upper margin; labrum lustrous and black, longer than head height; labellum dark and bearing several dark setae.

Thorax dark, largely densely grey pruinescent, with 2 distinct darker grey vittae between acr and dc rows. Proepisternum with 3–5 stout, dark setae on lower section; upper proepisternum in front of spiracle bare; prosternum bare. Antepronotum with row of short, stout dark setae. Postpronotum with several dark setae and 1–2 stouter and longer setae. Scutum with biserial acr, shorter than dc; dc uniserial, increasing in length posteriorly, anterior seta offset laterally; 1 strong presut spal (= posthumeral) and several finer setae; notopleuron with cluster of short, stout, dark setae anteriorly, 4–6 stronger and longer setae posteriorly; several fine prealar setae; 1–2 psut spal; 1 pal; 3 pairs of sctl setae. Laterotergite with cluster of long, pale setae. Anterior and posterior spiracles brown with dark outer ring.

Legs entirely dark reddish-brown; subshiny, coxae lightly greyish pruinescent. Fore coxa with row of stout, dark setae anteriorly; mid and hind coxae with several dark, stout, lateral setae; mid coxal setae slightly stouter than hind coxal setae. Femora with white ventral pile; hind femur with anteroventral setae dark, fine, doubling in length on apical half, never longer than femoral width ( Fig. 25B ); fore and mid femora with 1 anteroventral and 1 posteroventral row of setae, stouter and longer on midleg. Fore tibia with fine posterodorsal and posterior setae; ventral setae fine and short; circlet of stout preapical setae. Mid tibia with circlet of stout preapical setae; anteroventral and posteroventral rows of stout setae, stronger anteroventrally; anterodorsal and posterodorsal setae fine, somewhat longer than tibial width. Hind tibia evenly tapered apically; long anterodorsal and posterodorsal setae 2X tibial width on apical 2/3; anteroventral and posteroventral setae no longer than tibial width ( Fig. 25B ); 1 seta in posteroapical comb. Hind tarsomere 1 slightly thickened, broader than other tarsal segments with long anterodorsal and posterodorsal setae similar to those on tibia; tarsomere 1 of all legs with stout anteroventral and posteroventral setae.

Wing faintly infuscate with yellowish veins; all veins complete (except Sc and CuA+CuP), well sclerotized, except CuA+CuP faint and weak. Pterostigma infuscate; basal costal seta absent. Anal lobe well-developed; axillary incision obtuse. Halter with yellowish brown stem and blackish knob.

Abdomen dark grey, with reddish-brownish tinges on tergites, posterior margins of segments pale; clothed with long, hair-like, pale setae, longer laterally. Sternite 8 with many long, pale posteromarginal setae, subequal to length of sclerite; sternite 8 closely approximated laterally with tergite 8. Tergite 8 half-length of sternite 8; bearing many shorter, fine, pale setae posteriorly.

Terminalia ( Figs 25A, C ) dark, contrasting with exposed pale phallus, especially swollen base. Epandrium subtriangular, with lighter brown tinge in depression on middle of lamella; long pale setae along ventral margin and dorsal margin; expanded subapically bearing many dark, short, spine-like setae; apex prolonged into short finger- like lobe, bearing long pale setae. Cercus cylindrical, about half epandrial length; dorsal margin of cercus lined with fine, short setae. Subepandrial lobe of subequal length to cercus, tear drop-shaped, apex bearing several fine, long setae ( Fig. 25C ). Hypandrium U-shaped, ending at base of phallic expansion. Phallus strongly arched at base with sub-basal expansion bearing many short, fine setae; remaining phallus slender, without loops, extending beyond and outside epandrium; apex recurved; ejaculatory apodeme fan-shaped, almost with 90° angle, small, with lateral “wings” shorter than vertical wing.

Female. Similar to male except frons with several pairs of setulae; wing more darkly infuscate; legs and abdomen with much shorter setation; legs without pennate setae.

Distribution. This species is known from a few localities along the Beaufort Sea and the Pribilof Islands in the Bering Sea ( Fig. 27 ). This distribution pattern in the low arctic is termed “southern arctic—western” by Danks (1981, fig. 65), for tundra species of the coastal plain.

Etymology. The specific name is from the Latin frigidus (cold, inactive), in reference for it distribution along the edge of the Beaufort and Bering Seas.

Remarks. Rhamphomyia (Pararhamphomyia) frigida sp. nov. is assigned to the R. lapponica (= rufipes Zetterstedt ) species group (Saigusa unpubl. data) and will key to the R. caesia species group in Barták & Kubík (2009). See Barták & Danielson (2007) for note on possible unjustified replacement name ( R. lapponica ) for R. rufipes (Zetterstedt) by Frey (1955a: 484). The R. lapponica group is defined here by pale halteres, male hind femur more or less thickened and hind tibia densely short setose ventrally. The cerci of the male terminalia are small and lobate, with subepandrial lobes simple and short setose; the epandrium is broad, moderately long, with a subdorsal cluster of stiff setae towards the tip; and the phallus is slender, extending posteriorly beyond the epandrium, often waved and recurved to base of cercus.

Figures

FIGURE 25. Rhamphomyia (Pararhamphomyia) frigida sp. nov. A. Male terminalia, lateral view; B. Male hindleg, anterior view; C. Male terminalia, lateral view.

FIGURE 26. Known distribution of Rhamphomyia (Pararhamphomyia) frigida sp. nov. in North America (arrow indicates localities beyond border of map).

FIGURE 27. Rhamphomyia (Pararhamphomyia) helleni Frey. A. lectotype, lateral view; B. type labels.

FIGURE 28. Rhamphomyia (Pararhamphomyia) helleni Frey. A. Male terminalia, lateral view; B. Male terminalia, phallus, lateral view; C. Male hindleg, anterior view; D. Female hindlegs, posterior views.