Rhamphomyia (Pararhamphomyia) wrangeli 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 : 46-49

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

( Figs 49–53 )

urn:lsid:zoobank.org:act:D1A835B2-FA2B-4104-B593-F6A43BDDFA89

Type material. HOLOTYPE ♂, labelled [ RUSSIA. Chukotka AO ( Wrangel Island )]: “[printed in Cyrillic, Russian] bukh. [=bukhta, bay] Somnitelnaya,/ south of o. [=ostrov, island] Wrangel/ Gorodkov 19.vii.[1]966”; “on flower/ Dryas integrifolia ,/ spotted/ tundra”; “ Holotypus / Rhamphomyia / wrangeli / Shamshev, Sinclair sp. n. [red label]” (INS_DIP_0000617, ZIN).

PARATYPES: RUSSIA: Chukotka AO ( Wrangel Island ): same data as holotype, (1 ♂, 7 ♀, ZIN; 1 ♂, 1 ♀, CULSP ); environs of Somnitelnaya Bay , south of Wrangel Island , valley of river Somnitelnaya, Mineev Mtns, 150 m, pebbles, on flower of Dryas integrifolia , 19.vii.1966, KBG (1 ♂, 4 ♀, ZIN; 1 ♂, 1 ♀, CNC) ; same locality, on flower of Potentilla emarginata , 22.vii.1966, KBG (2 ♂, ZIN) .

Diagnosis. Small dark flies (wing length about 3.5 mm). Male holoptic; scutum almost uniformly brownish grey pruinescent, acr and dc biserial, usually 6 sctl; wing faintly brownish, anal vein incomplete, halter brown; hind tibia strongly curved inward on about basal third; abdominal segments 7 and 8 asymmetrical; terminalia small, slightly rotated to right, phallus mostly hidden. Female legs with simple setae.

Description. Body length 3.2–3.5 (holotype 3.3); wing length 3.2–3.4 (holotype 3.2) mm. Male ( Fig. 49 ). Head with dense greyish brown 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 several long fine setae. Occiput with numerous long setae, including postoculars; postgena with numerous hair-like setae. Antenna blackish brown; 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, nearly as long as postpedicel basal width. Palpus dark; with several long, dark fine setae. Proboscis with labrum dark reddish-brown, nearly as long as head height.

Thorax dark in ground-colour, greyish brown pruinescent; with black setation; scutum almost uniformly brownish grey pruinescent (dorsal view), without vittae. Proepisternum with tuft of several 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 and several short setae. Mesonotum with well-differentiated setae but their number, position and robustness variable; 1 presutural intra-alar, 1–2 presut spal (with some additional short fine setae), 3–4 npl (with finer short setae anteriorly), 1–2 psut spal (with additional setulae anteriorly), 2 pal, 6–8 sctl (usually 6); acr short, arranged 2 close irregular rows, lacking on prescutellar depression; presutural dc longer than acr, arranged in 2 irregular rows, postsutural dc 1–2-serial, 3–4 prescutellars longest. Laterotergite with numerous long fine setae. Anterior and posterior spiracles brown.

Legs slender, uniformly brownish; mostly subshiny, coxae and trochanters with denser greyish pruinescence; black setose. Fore coxa covered with long fine setae anteriorly. Hind tibia strongly curved inward on about basal third (posterior view), remaining podomeres unmodified. Mid and hind femora whitish pilose ventrally. Fore femur with rows of anteroventral and posteroventral very short fine setae (somewhat longer near base of femur), some moderately long setae anteriorly toward apex; mid femur with rows of short anteroventral and posteroventral setae (longest setae at most as long as half of femur width), some moderately long setae anteriorly; hind femur with moderately long anteroventral setae somewhat denser and longer on about apical third, some similar setae anteriorly and posteriorly. Fore tibia covered with moderately long fine setae posterodorsally (some setae usually slightly stronger); mid tibia with 3–4 posterodorsal, short spine-like setae ventrally toward apex; hind tibia covered with moderately long setae dorsally (longest setae slightly longer than tibia median width); no seta in posteroapical comb. Fore basitarsus with similar to fore tibia setae posterodorsally; hind basitarsus with similar to hind tibia setae posterodorsally.

Wing membrane faintly brownish, with brownish veins; CuA+CuP (anal vein) incomplete. Pterostigma brownish yellow. One basal costa seta present. Anal lobe well-developed; axillary incision right-angled. Squama brown, dark fringed. Halter brown.

Abdomen ( Fig. 50 ) with segments 1–6 brownish, segments 7–8 blackish brown, all segments faintly brownish grey pruinescent, subshiny; segments 1–6 mostly covered with moderately long dark setae, short setae on tergites dorsally. Tergite and sternite 6 slightly concave posteriorly. Sclerites of segments 7 and 8 strongly modified ( Figs 51–53 ), asymmetrical and stronger sclerotized (darker) than preceded segments. Segment 7 with tergite and sternite narrowly fused anteriorly. Tergite 7 slightly asymmetrical, large, longer than tergite 6, subrectangular viewed dorsally, with straight posterior margin; minute setulae posteriorly. Sternite 7 strongly asymmetrical, inflated, narrowly deeply concave posteromedially, with produced left lateral margin, free laying internal lateral narrow sclerite supporting anterior lateral projections of segment 8; covered with numerous short setae denser and somewhat stronger around posterior concavity. Segment 8 slightly rotated to right, with fused tergite and sternite (no trace of suture), slightly asymmetrical ventrally; large subtriangular anterior dorsomedial projection and 2 broad digitiform anterior lateral projections inserted into tergite 7, subtriangular anterior ventromedial projection (corresponding to posterior concavity on sternite 7); numerous long setae along posterior margin laterally and ventrally, scattered minute setulae dorsally.

Terminalia ( Figs 51–53 ) slightly rotated to right, small, dark brown. Cerci separated from epandrium, not extended anteriorly beyond posterior margin of tergite 8, without pair of subepandrial lobes beneath; in lateral view cercus shorter than epandrium, subrectangular, with straight upper margin, slightly rounded apically; in dorsal view cercus strongly convex laterally and deeply concave on inner margin, with short broad subapical projection directed downward; mostly covered with minute setulae, subapical projection with dense spinule-like setulae. Epandrium narrowly subtriangular; with some moderately long setae along lower margin and closer to apex. Hypandrium invisible in situ, mostly membranous, only lateral arms sclerotised. Phallus mostly hidden, only short portion between posterior margin of sternite 8 and lower margin of epandrium visible; short, thicker on about basal third and uniformly slender on remaining portion, gently arcuate, hook-like curved to left at extreme apex. Ejaculatory apodeme slightly extended beyond basal curvature of phallus, with subequally narrow lateral and vertical wings.

Female. Similar to male, except frons broad, with marginal setulae, ommatidia of equal size; sometimes upper proepisternum in front of spiracle with 1 seta; legs with short setae, no pennate setae, hind tibia simple; wing darker, uniformly brownish infuscate; cercus long slender, with dark setulae.

Distribution. Russia (Chukotka Autonomous Okrug: Wrangel Island).

Etymology. The specific name is a patronym in honour of Ferdinand Petrovich Wrangel (Baron Ferdinand von Wrangel, a Baltic German), a Russian explorer and seaman, and one of the founders of the Russian Geographic Society. Wrangel Island was named in 1867 by Thomas W. Long, an American whaling captain.

Remarks. The male of the new species can be readily distinguished from other groups of Pararhamphomyia recognised by Barták & Kubík (2009) in the characters noted in the key. Several undescribed species of this group occur in North America.

Habitat. This species was collected from Wrangel Island only in 1966, and in one area (environs of Somnitelnaya Bay), mainly on the flowers of Dryas integrifolia .

Figures

FIGURES 49–53. Rhamphomyia (Pararhamphomyia) wrangeli sp. nov., male. 49. habitus, holotype, lateral view; 50. abdomen, right lateral view; 51. postabdomen, macerated, right lateral view; 52. same, macerated, dorsal view; 53. same, outline (setation omitted), dorsal view. Abbreviations: cerc—cercus; epand—epandrium; ph—phallus; sg 8—segment 8; st 7—sternite 7; tg 7—tergite 7.