Rhamphomyia (Pararhamphomyia) subtenuiterfilata Shamshev & Sinclair, 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 : 43-45

Rhamphomyia (Pararhamphomyia) subtenuiterfilata Shamshev & Sinclair sp. nov.

( Figs 45–47 )

urn:lsid:zoobank.org:act:A3936415-AFA7-4469-8A77-E07648EAAAF3

Type material. HOLOTYPE male, labelled: [Chukotka AO ( Wrangel Island ):] “[printed in Cyrillic, Russian] bass. [=basseyn, basin] r. [=reka, river] Khischniki/ 7 km SO g. [=gora, mountain] Sovetskaya/ o. [=ostrov, island] Wrangel/ Gorodkov 15.vii.[1]972”; “ Holotypus / Rhamphomyia / subtenuiterfilata / Shamshev, Sinclair sp. n. [red label]” (INS_DIP_0000616, ZIN; terminalia dissected, in microvial pinned with specimen).

PARATYPES: RUSSIA. Chukotka AO (Wrangel Island): Somnitelnaya Bay , 400 m, S Sovetskaya Mtn, 20.vii.1966, KBG (1 ♀, ZIN) . Yakutia: Indigirka River, lower flow of river Ystan-Yuryakh, Momskiy District , 29.vi.1976, V . Kovalev (1 ♂, ZMMU) .

Diagnosis. Mid-sized (wing length about 4.5 mm), blackish, subshiny flies. Male holoptic; thorax and abdomen black setose, scutum subshiny, anepisternum pruinescent; legs dark brown, hind basitarsus clavate, hind tibia with moderately long setae and hind tarsomeres 1–2 with numerous long fine setae dorsally; abdomen almost shiny, epandrium and cerci elongate, cercus spatulate beyond dorsal cavity; phallus well exposed, filamentous, long, gently curved. Female with brownish infuscate wing, short setose slender legs without pennate setae.

Description. Wing length 4.7 mm. Male ( Fig. 45 ). 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 moderately 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, nearly 2X longer than wide; stylus very short, slightly shorter than half of postpedicel basal width. Palpus dark; with several long, dark fine setae. Proboscis with labrum dark brown, nearly as long as head height.

Thorax dark in ground-colour, faintly greyish pruinescent (except noted), with black setation; postpronotal lobe and mesonotum almost uniformly shiny, very faintly pruinescent (somewhat denser on scutellum). 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 long stronger and several shorter fine setae. Mesonotal setation: 1 presut spal (with some additional short fine setae), 3 npl (with several additional fine setae anteriorly), 1 psut spal (with additional setulae anteriorly), 1 pal, 4 sctl (in holotype 5); acr very short, cilia-like, arranged in 2 close irregular rows, lacking on prescutellar depression; presutural dc similar to 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 (except noted), uniformly brownish; mostly shiny, coxae and trochanters faintly greyish pruinescence; black setose. Fore coxa covered with long fine setae anteriorly. Hind femur slightly thickened on about apical half; hind tibiae slightly evenly thickened toward apex; hind basitarsus clavate, about 1.5X broader at middle than apex of hind tibia; hind tarsomere 2 expanded. All femora whitish pilose ventrally, short setose (except noted). Fore femur with minute anteroventral and posteroventral setae. Mid femur with rows of moderately long anteroventrals (4–5 setae near base longer) and posteroventrals (somewhat longer on about apical half). Hind femur with numerous moderately long setae anteroventrally on about apical third. Fore and mid tibiae with some slightly longer fine setulae posteriorly, mid tibia with numerous stronger long anteroventral and posteroventral setae on about apical 2/3; hind tibia with moderately long fine setae dorsally (longest setae only slightly longer than tibia width), 1 long seta in posteroapical comb. Fore and mid tarsomeres short setose; hind tarsomeres 1–2 with long, dense erect fine setae dorsally, tarsomere 3 with slightly longer setae dorsally.

Wing membrane faintly infuscate, with brownish veins; CuA+CuP (anal vein) incomplete, evanescent apically, almost reaching wing margin as fold. Pterostigma brownish yellow. Basal costal seta absent. Anal lobe welldeveloped; axillary incision right-angled. Squama brown, dark fringed. Halter brownish.

Abdomen dark brown, almost shiny, very faintly pruinescent; mostly with black fine moderately long setae. Segments 6–7 unmodified. Segment 8 with separated tergite and sternite; tergite 8 simple, entire, subtriangular viewed laterally, very narrow mid-dorsally, broadly concave anteriorly, with almost straight posterior margin, numerous moderately long setae along posterior margin; sternite 8 simple, enlarged, subrectangular in lateral view, V-shaped viewed posteriorly, covered with numerous long setae posteriorly.

Terminalia ( Fig. 46 ) dark brown, directed obliquely upwards. Cerci ( Fig. 47 ) separated from each other and from epandrium, not extended beyond tergite 8 anteriorly; cercus long, broadly deeply concave on upper margin about middle, its middle portion very narrow, apical portion spatulate (lateral view), about 2.5X as broad as middle portion, with small internal subrectangular projection slightly beyond middle of cercus (dorsal view); covered with short fine setae on broadened anterior and posterior parts, lacking setation on narrowed middle portion; 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 row of 6–7 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 sinuate. Ejaculatory apodeme slightly extended beyond basal curvature of phallus, with narrow lateral wings and broad vertical wing.

Female. Frons broad, greyish pruinescent, with marginal setulae; body with shorter setation; hind femur uniformly slender, with short anteroventral setae over entire length; hind tibia and tarsi slender, covered with short setae; wing darker, distinctly brownish infuscate; abdominal segments 5–8 somewhat denser pruinescent (lateral view); cercus long, slender, with dark setulae.

Distribution. The new species is currently known only from Yakutia and Wrangel Island of Russia.

Etymology. The specific name refers to the similarity of the new species to R. tenuiterfilata Becker, 1900 .

Remarks. The new species is very similar to R. tenuiterfilata (known from Taymyr Peninsula) in the structure of the male hind leg and the terminalia. However, R. subtenuiterfilata differs from R. tenuiterfilata primarily by brownish halteres (vs. yellowish) and black setose abdomen (vs. pale setose).

Habitat. On Wrangel Island, the species is known from single specimens collected in the mountains.

Figures

FIGURES 45–47. Rhamphomyia (Pararhamphomyia) subtenuiterfilata sp. nov., male, holotype. 45. habitus, lateral view; 46. terminalia, lateral view; 47. cerci, dorsal view.Abbreviations: cerc—cercus; ej apod—ejaculatory apodeme; epand—epandrium; hypd—hypandrium; ph—phallus.