Rhamphomyia (Pararhamphomyia) longestylata Frey, 1913

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 : 35-36

Rhamphomyia (Pararhamphomyia) longestylata Frey

( Figs 36, 37 )

Rhamphomyia longestylata Frey in Poppius et al., 1917: 682 . Type localities: “Schwedisch-Lappland, Sarek: Pårte, Kåtokjokk”, Sweden.

Rhamphomyia longestylata Frey in Lundström & Frey, 1913: 8 (nomen nudum).

Rhamphomyia (Pararhamphomyia) longestylata Frey : Frey, 1922: 44 (revision); Melander, 1928: 196 (catalogue); Frey, 1955b: 485 (revision); Jonassen et al., 2013: 214 (faunistic survey); Kahanpää, 2014: 187 (checklist); Shamshev, 2016: 65 (checklist).

Rhamphomyia caudata : authors, nec Zetterstedt, 1838: Boheman, 1866: 570 ( Rhamphomyza ); Holmgren, 1869: 26; Collin, 1923: 116 (expedition results); Collin, 1961: 378 (revision); Hackman, 1968: 93 (faunistic survey); Chvála & Wagner, 1989: 299 (catalogue); Coulson & Refseth 2004: 104 (checklist Svalbard); Yang et al., 2007: 169 (catalogue).

Material examined. NORWAY. Spitsbergen (Svalbard Archipelago): Advent Bay, Holmgren (5 ♂, 6 ♀, NHRS); Mimerdalen, Pyramiden, tundra, 29.viii.1979, KBG ; on flowers of Dryas octopetala (1 ♂, 1 ♀, ZIN) .

Diagnosis. Mid-sized (wing length about 4 mm), blackish, shiny flies. Male ( Fig. 36 ) holoptic; thorax and abdomen black setose, scutum and anepisternum shiny; legs dark brown, hind basitarsus slightly uniformly thickened, all tibiae and tarsi clothed in long numerous fine setae but hind tibia with long setae on about apical half only; abdomen shiny, epandrium and cerci elongate, cercus finger-like beyond dorsal cavity; phallus well exposed, filamentous, long, gently curved. Female with brownish infuscate wing, short setose slender legs without pennate setae.

Redescription. Wing length 3.7–4.1 mm. Male ( Fig. 36 ). Head with faint greyish pruinescence on face, frons, postgena, ocellar triangle and occiput; dark setose. Holoptic; upper ommatidia enlarged. Frons represented by very small subtriangular space below ocellar tubercle and larger subtriangular space above antennae, bare. Face broad, bare. Ocellar triangle with 2 long fine and some short setae. Occiput with numerous long fine setae, including postoculars; postgena with numerous hair-like setae. Antenna blackish; scape short, slightly longer than pedicel, both with short setulae; postpedicel conical, with slightly concave ventral margin on apical part, nearly 2.5X longer than wide; stylus short, slightly shorter than postpedicel basal width. Palpus dark; with several long, dark fine setae. Proboscis with labrum dark reddish-brown, nearly 1.3X as long as head height.

Thorax dark in ground-colour, with black setation; prothoracic sclerites mostly densely greyish pruinescent, antepronotum and postpronotal lobe faintly pruinescent, subshiny; mesonotum almost entirely shiny, only notopleuron along lower margin,postalar tubercle,scutum in front of scutellum and scutellum very faintly pruinescent;mesopleuron mostly greyish pruinescent, anepisternum shiny, also usually katepisternum on upper part and anepimeron anteriorly shiny. Proepisternum with few moderately long fine setae on lower section; upper proepisternum in front of spiracle without setae. Prosternum bare. Antepronotum with several short setae. Postpronotal lobe with 1–2 long, stronger and several shorter fine setae. Mesonotal setation: presutural supra-alar space with several long fine setae, 3–4 npl (with numerous finer setae anteriorly), 1–2 psut spal (with additional setulae anteriorly), 2 pal (often with additional setulae), 4–6 sctl (usually 6, variable in length and robustness, sometimes asymmetrically set); acr short, fine, arranged in 2 close irregular rows, lacking on prescutellar depression; presutural dc longer than acr, fine, arranged in 2 irregular rows, postsutural dc 1–2-serial, 3–4 prescutellars longest. Laterotergite with several long fine setae. Anterior and posterior spiracles brown.

Legs slender, uniformly brownish; mostly shiny, coxae and trochanters faintly greyish pruinescence; black setose. Fore coxa covered with long fine setae anteriorly. All tibia slightly evenly thickened toward apex; hind basitarsus slightly uniformly thickened, nearly as broad as hind tibia width at apex. All femora whitish pilose ventrally, with very short setation; fore and mid femora with anteroventral and posteroventral rows of short fine setae; hind femur with row of short anteroventral setae. Fore and mid tibiae with numerous long fine setae dorsally and posteriorly (about 2X tibial width); mid tibia with numerous stronger long anteroventral and posteroventral setae on about apical 2/3; hind tibia with long fine setae dorsally on about apical half, 1 long seta in posteroapical comb. Tarsomeres 1–2 of all legs with numerous long setae dorsally (somewhat longer on basitarsi).

Wing membrane faintly infuscate, with brownish veins; CuA+CuP (anal vein) incomplete, evanescent apically. Pterostigma brownish yellow. Basal costa seta absent. Anal lobe well-developed; axillary incision right-angled or slightly obtuse. Squama brown, dark fringed. Halter brown.

Abdomen dark brown, shiny; mostly with black fine moderately long setae. Segments 6–7 unmodified. Segment 8 with almost fused tergite and sternite; tergite 8 simple, entire, about half length of sternite 7, with straight posterior margin, with numerous long setae along posterior margin; tergite 8 simple, enlarged, subrectangular in lateral view, V-shaped viewed posteriorly, covered with numerous long setae posteriorly.

Terminalia ( Fig. 37 ) dark brown, directed oblique upstairs. Cerci separated from each other and from epandrium, not extended beyond tergite 8 anteriorly; cercus long, narrow, broadly concave on upper margin, apical portion finger like, parallel-sided (lateral view), at least as broad as middle portion, with small internal subtriangular projection slightly beyond middle (dorsal view); covered with short fine setae; without pair of subepandrial lobes beneath. Epandrium subrectangular, elongate, about 4X as long as broad, broadly concave on upper margin, with straight lower margin, somewhat broadened and angularly expanded apically, extended slightly beyond cerci posteriorly; with cluster of numerous long dark setae near upper anterior corner, covered with dense fine setulae on broadened apical part, some numerous moderately long setae along lower margin. Hypandrium very narrow, rim-like, entire, well sclerotized; bare. Phallus well exposed, long; mostly hair-like, knob-like thickened just beyond hypandrium; with right-angle curvature shortly beyond basal thickening, otherwise gently arcuate. Ejaculatory apodeme not extended beyond basal curvature of phallus, with broad lateral wings and narrower vertical wing.

Female. Similar to male, except dichoptic, frons broad, shiny, with marginal setulae; wing brownish uniformly infuscate; leg with tibiae and tarsi slender, with short setation, without pennate setae; abdomen covered with short setae; cercus long slender, with dark setulae.

Distribution. Palaearctic; R. longestylata is recorded only from northern Scandinavia ( Finland, Norway, Sweden), nearby regions of Russia (Murmanskaya Province, Nenets) and Spitsbergen Island ( Norway).

Remarks. Rhamphomyia longestylata is assigned to the R. caudata group ( Sinclair et al. 2019) or to the R. longestylata group ( Barták & Kubík 2009). It is very similar to R. ursinella and the main differences between these species are provided in the key. We have examined the syntypes of R. longestylata (housed in MZH and NHRS), but the lectotype has not been designated.

Figures

FIGURES 36–38. Rhamphomyia (Pararhamphomyia). 36. R. (P.) longestylata Frey, male habitus, lateral view; 37. same species, male terminalia, lateral view; 38. R. (P.) nordqvistii Holmgren, female habitus, lectotype, lateral view (from Shamshev & Sinclair 2018: 314, fig. 10). Abbreviations: cerc—cercus; ej apod—ejaculatory apodeme; epand—epandrium; hypdhypandrium; ph—phallus.