Platypalpus subtectifrons 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 : 63-66

Platypalpus subtectifrons Shamshev & Sinclair sp. nov.

( Figs 73–76 )

urn:lsid:zoobank.org:act:FC7E4A07-9126-4941-A797-489575CA0E21

Type material. HOLOTYPE ♂, labelled: [ RUSSIA. Chukotka AO ( Wrangel Island )] “sr. tech. r. [=srednee techenie reki, =middle flow of river] Mamontovaya, N/ Perkatkun, o. [=ostrov, island] Wrangel/ willows in river valley/ Gorodkov 17.vii.[1]972”; “ Holotypus / Platypalpus / subtectifrons / Shamshev, Sinclair sp. n. [red label]” (INS_DIP_0000620, ZIN).

PARATYPES. CANADA. Northwest Territories: Aklavik , 2.vii.1956, R . E. Leech (1 ♀, CNC); same data except, 25.vi.–3.vii.1956, E.F. Cashman (3 ♀, CNC); Fort McPherson , 17–19.vii.1957, R . Hurley (2 ♀, CNC); 21 mi E Tuktoyaktuk, 8–12.vii.1972, D.M. Wood (2 ♂, 1 ♀, CNC); Tuktoyaktuk , 69°26′16.2″N 133°1′2.16″W, pan traps, meadow, 15–18.vii.2010, Goulet & Boudreault (12 ♂, 4 ♀, CNC) . Yukon: British Mtns, Firth River, 25.vii.1956, E.F. Cashman (2 ♀, CNC); Firth River , 14.vii.–7.viii.1956, E.F. Cashman (5 ♂, 7 ♀, CNC); same data except, 20.vii.–3.viii.1965, R.E. Leech (5 ♂, 8 ♀, CNC) . RUSSIA. Chukotka AO ( Wrangel Island ): Same data as holotype (4 ♂, 1 ♀, ZIN; 2 ♂, 1 ♀, CNC); 21.vii.1972, KBG (1 ♂, 4 ♀, ZIN) ; middle flow of river Neizvestnaya , 71°20.287′N 179°29.779′W, BT 1 , 5–14.vii.2018, U. V. Babiy (3 ♂, 3 ♀, ZIN); middle flow of river Mamontovaya , 71°10′N 179°45′W, BT 2 , 30.vi.–9.vii.2006, OAK (1 ♂, ZIN); same locality and biotope, BT 2 , YPT, 2–4.vii.2015, OAK (2 ♂, ZIN); same locality, 71°10′N 179°45′W, BT 1 A, YPT, 2–4.vii.2015, OAK (3 ♂, 3 ♀, ZIN); same locality, 71°10′N 179°45′W, BT 14 , Sw, 2.vii.2015, OAK (2 ♂, 1 ♀, ZIN); same locality, 71°10′N 179°45′W, 3.vii.2015, OAK (1 ♂, ZIN); Tundrovaya Mnt , 71°18′N 179°49′W, BT 2 , 1–19.vii.2015, LFV (1 ♂, ZIN; dissected) . USA. Alaska: Cape Thompson , 23–25.vii.1961, R. Madge (2 ♀, CNC); Isabel Pass, mi 206 Richardson Hwy, 2900 ft, 18.vii.1962, P.J. Skitsko (2 ♀, CNC); Nome Area , mi 46 Kougarok Rd , 64°57′27″N 168°48′21″W, 26–28.vi.2005, MT, J. & R. Skevington (1 ♂, CNC); Prudhoe Bay, 9.vii.1971, M. Deyrup (1 ♂, 6 ♀, CNC); Umalakleet , 18, 28. vi.1961, B.S. Heming (1 ♂, 1 ♀, CNC); same data except, 28.vi., 8.vii.1961, R. Madge (1 ♂, 1 ♀, CNC); Umiat , 3–25.vii.1959, R. Madge (3 ♂, 38 ♀, CNC); same data except, 6–15.vii.1959, J.E.H. Martin (26 ♂, 28 ♀, CNC); same data except, 4.viii.1959, B.N. Smallman (1 ♂, CNC) .

Diagnosis. Small, blackish species of the P. pallidiventris group; one pair of vertical setae, postpedicel nearly 1.5X longer than wide, palpus black, thorax with pale setae, scutum entirely pruinose, acr biserial, legs almost entirely dark brown, hind tibia with long apical spur, abdomen almost entirely shiny.

Description. Body length 2.4–2.5 (holotype 2.5), wing length 3.0–3.2 (holotype 3.1) mm. Male ( Fig. 73 ). Head black, mostly pale setose, ocellar setae rather yellowish. Occiput entirely densely greyish pruinose; with one pair of moderately long, fine, wide apart vertical setae; numerous short setae on upper part and longer setae on lower part. Ocellar tubercle concolorous with occiput, with 2 long, lateroclinate anterior setae and 2 minute posterior setae. Frons broad, only slightly narrowed toward antennae, below ocellar tubercle broader than distance between outer margins of posterior ocelli; densely light grey pruinose (anterior view). Face broad, almost as broad as frons above antennae, densely whitish pruinose (including clypeus). Antenna uniformly dark brown; postpedicel short, nearly 1.5X (in holotype 1.65X) as long as basal width; stylus nearly 2X (in holotype 2.2X) longer than postpedicel. Gena narrow, shiny. Proboscis dark brown, elongate, nearly 1.5X shorter of head height. Palpus black, small, oval, whitish pubescent, with few short setae.

Thorax black, mostly pale setose, strong setae rather pale yellowish; prothoracic sclerites and mesopleuron densely greyish tomentose, scutum rather yellowish grey faintly tomentose; katepisternum mostly shiny, only tomentose on upper anterior corner and along posterior corner. Postpronotal lobe with 1 moderately long fine seta and some minute setulae. Mesonotum with 2 moderately long npl (with numerous additional setulae), 2 pal (1 longer), 4 sctl (apical pair long, lateral pair finer and shorter; sometimes additional setae present); some setulae behind postpronotal lobe and on supra-alar space; acr short, fine, arranged in 2 moderately broad irregular rows, on prescutellar depression hardly distinguishable from dc and sometimes more numerous; dc arranged in 2–3 irregular rows and mostly similar to acr, some prescutellars longer.

Legs extensively dark brown, subshiny, pale setose (except noted), somewhat variable in yellowish pattern. In holotype and most paratypes fore femur very narrowly yellowish apically, mid and hind femora yellowish brown on extreme apex, fore tibia yellowish near base (becoming brownish toward apex); mid and hind tibiae slightly paler than corresponding femora, tarsomeres somewhat paler on basal part (broadly on basitarsus, extreme base on remaining tarsomeres); in addition, in some paratypes fore coxa on extreme apex and all femora on extreme base yellowish brown (1 ♂ and 5 ♀ from Perkatkun). Fore coxae broadly shiny laterally, otherwise densely greyish tomentose; mid and hind coxae almost entirely shiny; all coxae pale setose; hind trochanter with fine setulae. Fore femur strongly thickened; pilose ventrally; with rows of long, fine anteroventral and posteroventral setae (longest setae on basal part slightly longer than half of femur width). Mid femur slightly stouter than fore femur; with double row of short, blackish spine-like setae ventrally, row of long strong posteroventrals intermixed with shorter and finer setae. Hind femur slender, with somewhat longer anteroventral setae on about apical half. Fore tibia slightly uniformly thickened; with simple setulae dorsally, some anterodorsals slightly stronger; longer setae ventrally and posteroventrally (longest ones on subapical part slightly longer than tibia width). Mid tibia with row of ventral dark spinule-like setulae; apical spur long, pointed, with two setulae at tip. Hind tibia slender, straight, with simple setulae. Tarsi of all legs unmodified; fore basitarsus with longer setae ventrally and posteroventrally (similar to those on fore tibia).

Wing faintly infuscate, with brownish veins. Basal costal seta moderately long, fine, pale. Veins R 4+5 and M 1+2 slightly convergent near wing margin; CuA straight, perpendicular, faint apically; anal vein very faint; crossveins m-cu and r-m slightly separated. Calypter dirty yellow, pale fringed. Halter yellow.

Abdomen entirely blackish brown, almost entirely shiny, only tergite 1 faintly greyish pruinose laterally; covered with numerous pale hair-like setae longer on tergites laterally.

Terminalia ( Figs 74–76 ) small, concolourous with abdomen, epandrium shiny. Right cercus ( Fig. 75 ) digitiform, long, almost parallel-sided toward apex, truncate; covered with short simple setae. Left cercus digitiform, slightly longer and narrower (on apical half) than right cercus (dorsal view), almost parallel-sided toward apex, rounded on apex; covered with short simple setae. Hypoproct subtriangular, narrow (dorsal view), with pointed apex almost reaching apex of cerci. Right epandrial lamella ( Fig. 74 ) subtriangular viewed laterally, with row of several long subapical setae; right surstylus well differentiated from apex of epandrial lamella, long, slender, with some minute marginal setulae. Left epandrial lamella subtriangular ( Fig. 76 ) somewhat concave about mid-ventrally; with numerous long pale yellow setae along about apical 2/3 of ventral margin.

Female. Similar to male. Visible parts of tergites 7 and 8 densely greyish pruinescent (except narrow upper margin of sternite 8); cercus long, slender.

Distribution. Palaearctic: Russia (Chukotka Autonomous Okrug, Wrangel Island). In North America, this species is known from Alaska, Northwest Territories and Yukon.

Etymology. The specific name refers to the similarity of the new species to P. tectifrons (Becker) .

Remarks. This new species strikingly resembles the poorly known P. tectifrons (Becker, 1907) described from eastern Tibet of China (syntypes housed in ZIN), which has the same pattern of leg colour and other main characters. The redescription of P. tectifrons will be published in a forthcoming paper. Platypalpus tectifrons differs from the new species by the somewhat narrower, longer postpedicel (about 2.5X longer than wide) and brownish to brownish yellow main mesonotal setae. Within the key to Platypalpus compiled by Chvála (1989), the new species would run to P. interstinctus (Collin, 1926) and P. pseudofulvipes (Frey, 1909) ( P. pallidiventris group). Platypalpus interstinctus (somewhat variable in leg colour) differs from the new species by distinctly black annulated tarsi, brownish vertical, acrostichal and dorsocentral setae, as well as by details of the male terminalia ( Chvála 1975: 178, figs 441–443). Platypalpus pseudofulvipes can be readily distinguished from the new species primarily by the spindle-shaped dilated fore tibiae. In addition, the new species could be compared with P. melancholicus ( Collin, 1961) , P. annulatus (Fallén, 1815) and P. carteri (Collin, 1926) . Platypalpus melancholicus and P. annulatus differ from the new species primarily by 4-serial acrostichals (at least on anterior part of mesoscutum). Platypalpus carteri can be distinguished from the new species by lateral pruinosity on all abdominal tergites. The male terminalia of the new species somewhat resemble those of P. notatus (Meigen, 1822) (especially cerci), however, P. notatus has longer postpedicel (about 2.5X longer than wide) and entirely shiny abdomen (including lateral area of first two tergites).

In addition, the new species was compared with the syntypes (currently in CNC) of the species known from subarctic areas of North America listed under above. All these species differ from the new species primarily by a combination of characters noted in the diagnosis.

Habitat. On Wrangel Island, this species was collected along riverbeds.

Genus Tachypeza Meigen

Figures

FIGURES 73–76. Platypalpus subtectifrons sp. nov., male. 73. habitus, holotype, lateral view; 74. right epandrial lamella, lateral view; 75. epandrium with cerci, dorsal view; 76. left epandrial lamella and left cercus, lateral view. Abbreviations: cerc—cercus; epand—epandrium; hypd—hypandrium; rt sur—right surstylus.