Rhamphomyia (Dasyrhamphomyia) mallochi Shamshev, Sinclair & Saigusa, 2020

Shamshev, Igor V., Sinclair, Bradley J. & Khruleva, Olga A., 2020, The empidoid flies (Diptera: Empidoidea, exclusive of Dolichopodidae) of the Russian Arctic islands and Svalbard Archipelago, Zootaxa 4848 (1), pp. 1-75 : 23-26

Rhamphomyia (Dasyrhamphomyia) mallochi Shamshev, Sinclair & Saigusa sp. nov.

( Figs 20–25 )

urn:lsid:zoobank.org:act:26E7A46E-1A47-4193-A5FF-FA5618C8E98E

Type material. HOLOTYPE ♂, labelled: [ RUSSIA, Chukotka AO:] “[in Cyrillic, Russian] Pevek [69°42′N 170°19′N], Chukotskij nats. [=natsionalny, national] okr. [=okrug, name of administrative unit] archadovaya/ tundra./ Gorodkov , 28.vi.[1]963”; “ Holotypus / Rhamphomyia / mallochi / Shamshev , Sinclair , Saigusa sp. nov. [red label]” (INS_DIP_0000614, ZIN).

PARATYPES: CANADA. Yukon: Dawson, 10,11. vii.1949, W.W. Judd (3 ♀, CNC); km 465 Dempster Hwy, 23–25.vi.1980, D.M. Wood & D. Lafontaine (1 ♂, CNC); Richardson Mts , 66°26.5′N 135°48′W, 3000 ft, 8.vii.1982, D. Wood (2 ♂, CNC) . RUSSIA. Chukotka AO (Wrangel Island): SE part of Rogers Bay, 20.vii.1932, A. Mineev (1 ♀, ZIN); SE part of Rogers Bay , 24.vii.1932, A. Mineev (1 ♀, ZIN); environs of Somnitelnaya Bay , valley of river Somnitelnaya , Mineev Mtns, 150 m, shingle, on flower of Dryas integrifolia , 19.vii.1966, KBG (1 ♂, ZIN); lower flow of river Khischniki , foothills of Mineev Mtns , marshy tundra, 11.vii.1972, KBG (1 ♂, 1 ♀, CNC); middle flow of river Neozhidannay , 71°01′N 179°09′E, BT G, 8–9.vii.2019, OAK (3 ♂, 1 ♀, ZIN); same locality, BT A, YPT, 8–9.vii.2019, OAK (2 ♀, ZIN); same locality, BT W, YPT, 8–9.vii.2019, OAK (1 ♂, ZIN); same locality, BT D, YPT, 8–9.vii.2019, OAK (1 ♀, ZIN); Inkali Mtn, 71°05′N 179°42′W, damp tundra, Sw , 17.vii.2019, OAK (1 ♀, ZIN) . Chukotka AO (Kolyuchin Island): Kolyuchin Island , 25–27.vii.1938, Hecker (5 ♂, 5 ♀, ZIN; 1 ♂, 1 ♀, CULSP) . Chukotka mainland: Apuka, island in delta of river Apuka, on flowers of cloudberry Rubus chamaemorus , 2.vii.1959 KBG (1 ♂, ZIN); Apuka, Pakhachinskij Range, mountain tundra, 7.vii.1959, KBG (1 ♂, ZIN); Pevek, 200–300 m, moist tundra, 29.vi.1963, KBG (1 ♂, ZIN); same locality, dryad tundra, 3.vii.1963, KBG (2 ♀, ZIN); same locality, osier-bed in valley, 8.vii.1963, KBG (1 ♂, ZIN); same locality, moist sedge tundra, 11.vii.1963, KBG (1 ♂, ZIN); same locality, mossy-sedge tundra, 18.vii.1963, KBG (7 ♂, 10 ♀, ZIN); Schmidt, on snow, 9.viii.1966, KBG (5 ♂, 1 ♀, ZIN); same locality, on snowfield, 16.vii.1966, KBG (6 ♂, 7 ♀, ZIN); same locality, polygon tundra, 11.vii.1971, KBG (2 ♂, 1 ♀, ZIN); same locality, spotted tundra, 17.vii.1971, KBG (9 ♂, 5 ♀, ZIN); same locality, S slope tundra with willow, 11.vii.1971, KBG (1 ♀, ZIN); valley of river Ichuvisi , Komsomolskij mine, Chaunskij District , shrubby tundra, 5.vii.1963, KBG (3 ♂, 2 ♀, ZIN); same locality, sedge tundra and osier-bed in river valley, 4.vii.1963, KBG (10 ♂, 3 ♀, ZIN); Iultin, water-logged sedge tundra, 21.vii.1963, KBG (11 ♂, 2 ♀, ZIN); 5 km N of Egvekinot, 27.vii.1963, KBG (1 ♂, ZIN) . USA. Alaska: Cape Thompson, 29.vii.1960, H.E. Erdman (1 ♀, CNC); Schrader Lake , 3–5.vii.1972, K.W. Philip (2 ♂, CNC) .

Additional material: RUSSIA. Chukotka AO (Wrangel Island): middle flow of river Neozhidannaya , 71°01′N 179°09′E, YPT, BT 4 , 12–16.vii.2016, LFV (1 ♂, ZIN); same locality, YPT, BT 3 , 12–16.vii.2016, LFV (3 ♀, ZIN) .

Diagnosis. A large species (body about 7 mm) with body and abdomen densely brownish pruinescent, halteres yellow, acrostichals biserial. Male: eyes separated by very narrow frons, legs yellowish to brownish yellow, hind femur with numerous short setae over entire length ventrally, hind tibia slender; wing membrane slightly infuscate; terminalia yellowish, cerci extended only to tergite 5. Female: mid and hind femora with posteroventral pennate setae.

Description. Male ( Fig. 20 ). Body length 6.9–7.3 (lectotype 7.1); wing length 6.9–7.4 (lectotype 7.3) mm. Head with dense brownish pruinescence on face, frons, postgena, ocellar triangle and occiput; dark setose. Eyes separated by frons; upper ommatidia slightly enlarged. Frons very narrow on middle part, at most as broad as anterior ocellus, slightly broader just below ocellar tubercle, forming larger subtriangular space above antennae, with scattered marginal setulae. Face broad, bare. Ocellar triangle with several fine setae of different lengths. Occiput with numerous long, thin setae, including postoculars; postgena with numerous finer setae than occiput. Antenna blackish brown; scape and pedicel short, scape slightly longer, both with short setulae; postpedicel conical, nearly 3X longer than wide; stylus rather long, nearly 1.5X shorter than postpedicel. Palpus dark; with long, dark fine setae. Proboscis with labrum dark reddish-brown, 1.2–1.3X head height.

Thorax dark in ground-colour, densely brownish pruinescent; with black setation; scutum brownish, without vittae. Proepisternum with tuft of numerous long setae on lower section; upper proepisternum in front of spiracle with 3–5 fine setae. Prosternum bare. Antepronotum with numerous short setae. Postpronotal lobe with numerous almost uniform fine setae of different lengths, sometimes 1–2 setae somewhat stronger. Mesonotum mostly with fine setae, including numerous undifferentiated similar presut spal, npl and psut spal (some posterior npl and psut spal somewhat longer and stronger but their number and position are very variable, often even on right and left sides), 2–3 pal with several shorter setae (number and robustness variable); 8–10 of subequally long sctl and some number of additional finer setae (number and robustness very variable); acr rather long, thin, arranged in 2 irregular rows, absent on prescutellar depression; presutural dc long, arranged in 3–4 irregular rows, postsutural dc less numerous, longer. Laterotergite with numerous long fine setae. Anterior and posterior spiracles yellowish.

Legs with coxae, trochanters and tarsi (except basal part of hind basitarsus) brownish, fore femur, mid femur ventrally, fore tibia toward apex, mid and hind tibiae at apex brownish yellow, remaining parts yellowish; mostly subshiny, coxae and trochanters with denser greyish pruinescence; black setose. Femora, tibiae and tarsomeres slender; hind femur of subequal thickness to fore and mid femora. Mid and hind femora whitish pilose ventrally (more distinctly on hind femur); fore femur with rather thin, moderately long setae anteroventrally and posteroventrally, longest setae closer to base slightly longer than half of femur basal width; mid femur with numerous strong, short setae anteroventrally and posteroventrally; hind femur entirely covered with setae ventrally (at most as long as half of femur width). All tibiae with some short ad and pd setae stronger on hind tibia; no seta in posteroapical comb of hind tibia. All tarsomeres covered with short, simple setae (except somewhat longer setae of subapical circlet); mid and hind basitarsi with short, strong setae ventrally.

Wing membrane faintly infuscate, mostly with brownish veins; all veins complete (except Sc). Pterostigma brownish yellow; basal costa seta absent.Anal lobe well-developed; axillary incision acute but closer to 90°. Squama yellow, dark fringed. Halter yellow.

Abdomen dark, densely brownish pruinescent; covered with uniform black setae shorter on tergites dorsally. Segments before segment 7 unmodified. Tergite 7 broadly concave posteriorly. Segment 8 with tergite and sternite separated.Tergite 8 upturned, with posterior margin recurved anteriorly, with numerous setae along posterior margin. Sternite 8 simple, scoop-like, with numerous long setae along posterior margin.

Terminalia ( Figs 21–24 ). Cerci yellowish; fused to epandrium (but suture distinct), broadly concave and flattened medially, strongly prolonged anteriorly, without pair of subepandrial lobes beneath; apical part of cercus (before epandrium) short, extended to tergite 5, subrectangular viewed laterally, subtriangular, with straight inner margin viewed dorsally, mostly bare, with some dark scattered setulae dorsally; posterior part of cercus very short, rounded, not extended beyond epandrium, covered with fine setulae. Epandrium almost entirely yellowish, only posterior digitiform projection brownish yellow (very rarely epandrium dark, 1 ♂ from Wrangel Island), faintly greyish pruinescent, with moderately long dark setae on upper part and longer setae along lower margin, posterior projection covered with black spinules dorsally; rather subrectangular (lateral view), somewhat humped dorsally, with short, digitiform projection on lower part posteriorly. Hypandrium yellowish, subtriangular (ventral view), entirely sclerotized, bare; gonocoxal apodeme large, broadened apically. Phallus ( Fig. 24 ) yellowish; short, mostly hidden (lateral view); gently arched, thick on about basal half, becoming abruptly slenderer beyond epandrial projection; with two minute lateral “spinules” slightly beyond thickened portion. Ejaculatory apodeme extended far beyond basal curvature of phallus, with narrow lateral wings and very broad vertical wing.

Female ( Fig. 25 ). Frons broad, parallel-sided; ocellar tubercle and occiput with somewhat shorter and stronger setae. Thorax with greyish pruinescence, scutum with 3 indistinct brownish vittae along rows of acr and dc; mesonotum with shorter setae. Legs often somewhat paler than in male (except coxae and trochanters) with only fore femur and tarsomeres darkened; mid and hind femora with complete rows of moderately long, pennate posteroventral setae. Abdomen with shorter setae; cercus long, slender, with dark setulae.

Distribution. Holarctic; in Eurasia, the new species is known from Chukotka mainland and nearby Arctic islands (Kolyuchin, Wrangel); in North America, this species is known from Alaska and Yukon, but unknown from the Canadian Arctic islands.

Etymology. The specific name is a patronym in honour of the J.R. Malloch, a world-renowned dipterist in the first half of the 20 th century, and among his numerous contributions were publications on Arctic Diptera (including Empididae ) of North America.

Remarks. The new species is most similar to R. hovgaardii differing from the latter primarily by brownish grey pruinescent thorax and abdomen (dark brown in R. hovgaardii ), yellowish halteres, extensively yellowish legs and yellowish epandrium (brown in R. hovgaardii ). The female of R. hovgaardii has pennate setae on the hind tibia. In addition, the new species could be compared with R. plumipes (Meigen) and R. vesiculosa (Fallén) . However, both these species can be readily distiguished from R. mallochi sp. nov. primarily by the much longer cerci of the male terminalia extending to abdominal tergite 2 and dark halteres.

Among material from North America, the species was recognised as Rhamphomyia (Dasyrhamphomyia) sp. 12 (Saigusa unpubl. data).

Habitat. Judging by the material of K.B. Gorodokov from 1950s–1970s, this species is most numerous in coastal areas in northern Chukotka (Pevek, Schmidt), where it was recorded in various habitats. On Wrangel Island, the largest series of specimens was collected in the colder regions of the island (Neozhidannaya River), where it was most numerous in the zonal spotted tundra. Moreover, in the warmer central region, the only specimen was found in a wetland below a snow field.

Figures

FIGURES 20–25. Rhamphomyia (Dasyrhamphomyia) mallochi sp. nov. 20. holotype male, habitus, lateral view; 21. male postabdomen, holotype, dorso-lateral view; 22. male terminalia, lateral view; 23. male terminalia, dorsal view; 24. phallus, lateral view; 25. female habitus, lateral view. Abbreviations: cerc—cercus; ej apod—ejaculatory apodeme; epand—epandrium; goncx apod—gonocoxal apodeme; hypd—hypandrium; ph—phallus.