Parathalassius sinclairi Cumming 2017, sp. nov.
Creators: name: Cumming, Jeffrey M.
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Diptera
Dolichopodidae
Parathalassius
Parathalassius sinclairi

description: Parathalassius sinclairi sp. nov.
(Figs 33, 44, 51, 54, 64, 68–71, 78–79, 82, 97–98, 118, 130–132, 137, 149)
Type material. HOLOTYPE ♂ labelled: “USA: OR: Tillamook Co. / Manzanita, N45°42′54.9″ / W123°56′25.4″, 3.vii.2014 / swp [swept] dunes & beach grass (Ammophila), J.M. Cumming ”; “ HOLOTYPE / Parathalassius sinclairi / Brooks & Cumming [red label]” (CNC). PARATYPES: USA: Oregon: same data as holotype (12♂, 11♀, CNC); same data as holotype except, CNC487121, CNC487160 (2♂, barcoded, CNC); same data as holotype except, S.E. Brooks (8♂, 12♀, CNC), same data except, CNC487161 (1♂, barcoded, CNC), CNC487162, CNC487163 (2♀, barcode-associated, CNC); same data as holotype except, S.H. Cumming (3♀, CNC).
Other material examined. CANADA: British Columbia: Haida Gwaii, Graham Is., 3km N Tlell [ca. 53°33′37″N 131°55′39″W], 13.vii.1988, meadow behind dunes, T.A. Wheeler (2♂, 1♀, CNC); same data except, CNC487131 (1♂, barcoded, CNC); Vancouver Island: Sannich Pen., Island View Beach, 48°34′37.56″N 123°22′5.09″W, 22.viii.2008, sandy beach with logs, S.E. Brooks (1♂, 1♀, CNC); same data except, J.M. Cumming (1♀, CNC); 6km SE Sidney, ex: beach, 25.vi–4. vii.1 999, J.M. Cumming (1♂, 1♀, CNC); Sidney Is., 48°38′28.06″N 123°19′50.05″W, 6.vii.1994, ex: veg along sandy beach, J.M. Cumming (1♂, 2♀, CNC). USA: Alaska: Aleutians East Borough: Cold Bay [ca. 55°11′49″N 162°41′55″W], 163°W, 21.viii.1952, W.R. Mason (1♀, CNC); Wosnesenski Island, 55.21688°N 161.36708°W, near shore, 11.vii.2009, H. Goulet & C. Boudreault (1♂, CNC); same data except, 11 m, YPT (1♂, CNC); same data except, A. Renaud (1♀, CNC); Aleutians West Census Area: Adak Island, 51.90201°N 176.61880°W, 9 m, swept, 15.vii.2009, A. Renaud (5♂, 2♀, CNC); Katmai [ca. 58°32′11″N 153°55′49″W], vii.1917, J.S. Hine (4♀, USNM). Oregon: Lane County: dunes behind Baker Beach, 44°04′39″N 124°06′44″W, 27.vi.2012, J.D. Pinto, UCRC ENT 431380 (1♂, UCRC); Heceta Beach, 44°02′14.7″N 124°07′57.2″W, 7.vii.2014, swept dunes & beach grass (Ammophila), J.M. Cumming (3♂, 5♂, CNC); same data except, CNC487168, CNC487169 (2♂, barcoded, CNC), CNC487170, CNC487171 (2♀, barcode-associated, CNC); Suislaw North Jetty, nr. Florence, 44°01′07.0″N 124°08′12.6″W, 7.vii.2014, swept dunes & beach grass (Ammophila), S.E. Brooks (8♂, 2♀, CNC); same data except, CNC487125, CNC487126, CNC487127 (3♀, barcode-associated, CNC); same data except, J.M. Cumming (1♂, 4♀, CNC); same data except, CNC487172, CNC487173 (2♂, barcoded, CNC); same data except, 8.vii.2014, S.E. Brooks (4♂, 11♀, CNC); same data except, J.M. Cumming (6♂, 6♀, CNC); same data except, CNC487174, CNC487175 (2♀, barcode-associated, CNC); Lincoln County: South Beach State Park, 44°36′05.6″N 124°03′54.0″W, 3.vii.2014, swept dunes & beach grass (Ammophila), S.E. Brooks (27♂, 25♀, CNC); same data except, CNC487122 (1♂, barcoded, CNC); same data except, J.M. Cumming (71♂, 89♀, CNC); same data except, CNC487164, (1♂, barcoded, CNC), CNC487123, CNC487166, CNC487167 (3♀, barcode-associated, CNC); same data except, S.H. Cumming (6♂, 3♀, CNC); 2.5mi. N Waldport [ca. 44°27′28″N 124°04′56″W], 1.vii.1971, Oman (1♂, 1♀, UGIC); Tillamook County: Cape Kiwanda, 45°12.9′N 123°58.3′W, beach, 3.viii.2005, D. & W.N. Mathis (1♂, USNM). Washington: Grays Harbor County: Copalis [ca. 47°06′37″N 124°11′06″W], 5.ix.1934, A.L. Melander (11♂, 8♀, USNM); Ocean City [ca. 47°04′15″N 124°10′37″W], 19.vii.1975, T.L. Whitworth (4♂, 3♀, LACM); Pacific County: Cape Disappointment State Park nr. Ilwaco, Benson Beach, 46°16′20.4″N 124°04′25.4″W, 1.vii.2014, swept dunes & beach grass (Ammophila) S.E. Brooks (204♂, 160♀, CNC; 2♂, 2♀, CSCA); same data except, CNC487133– CNC487137, CNC487141, CNC487142 (7♂, barcoded, CNC), CNC487143– CNC487150, CNC487152– CNC487157, CNC487184, CNC487186, CNC487194, CNC487195 (18♀, barcode-associated, CNC); same data except, 2.vii.2014 (20♂, 13♀, CNC); same data except, CNC487119, CNC487120, CNC487158 (3♀, barcodeassociated, CNC); same data except, 1.vii.2014, J.M. Cumming (180♂, 148♀, CNC); same data except, CNC487138–CNC487140 (3♂, barcoded, CNC), CNC487116, CNC487117, CNC487159 (3♀, barcodeassociated, CNC); same data except, 2.vii.2014 (20♂, 27♀, CNC); same data except, 1.vii.2014, swept dunes & beach vegetation, S.H. Cumming (32♂, 24♀, CNC); same data except, CNC487109, CNC487182 (2♀, barcodeassociated, CNC); same data except, 2.vii.2014 (37♂, 44♀, CNC); same data except, CNC487151 (1♀, barcodeassociated, CNC); Ilwaco, Cape Disappointment, 23.vii.1993, H. Ulrich (130♂, 76♀, ZFMK); same data except, 24.vii.1993 (76♂, 73♀, ZFMK); same data except, Benson Beach, dunes, 24.vii.1993 (34♂, 19♀, ZFMK); same data except, 25.vii.1993 (18♂, 10♀, ZFMK); same data except, 5.viii.1994 (173♂, 157♀, ZFMK); same data except, 9.viii.1994 (231♂, 118♀, ZFMK); same data except, sandy beach, 5.viii.1994 (2♀, ZFMK); same data except, 8.viii.1994 (10♂, 2♀, ZFMK); same data except, 9.viii.1994 (13♂, 18♀, ZFMK); same data except, 10.viii.1994 (18♂, 8♀, ZFMK); same data except, Waikiki Beach, on sand, 15.vii.1988 (2♂, ZFMK); same data except, dunes, 22.vii.1993 (15♂, 10♀, ZFMK); same data except, on wet sand, 25.vii.1993 (2♀, ZFMK); same data except, 26.vii.1993 (1♀, ZFMK); Ft. Canby State Park [= Cape Disappointment State Park], 29.vi.1988, W.N. & D. Mathis (4♂, USNM); Ilwaco [ca. 46°16′20″N 124°04′25″W], vii.1917, A.L. Melander (3♂, 1♀, USNM); same data except; 28.vi.1925 (1♀, USNM); same data except, 19.vii.1960, F.C. Harmston (1♂, USNM); Klipsan Beach [ca. 46°27′38″N 124°03′35″W], 14.vi.1975, W.J. Turner (1♂, 1♀, LACM); same data except, dunes (1♂, 1♀, USNM); Willapa Nat. Wildlife Ref., Willapa Bay, ca. 2 mi. N Oysterville [ca. 46°34′36″N 124°01′44″W], 22.vi.1989, R.S. Zack (1♂, 5♀, WSU).
Diagnosis. This medium sized species is characterized by an elongate-conical antennal postpedicel, longer lower male ommatrichia, 3 notopleural bristles, hyaline wing, and relatively dark legs with hind tarsomere 2 distinctly longer than tarsomere 3. Males have the face tinged with faint golden pruinosity, a comb-like anterodorsal row of short erect setae on the hind tibia, hind tarsomeres 2–4 bearing short thick perpendicular peglike setae dorsally, and distinctive cerci, while females possess apical rugosity on sternite 8.
Description. Male: Body length 2.3–3.2 mm, wing length 2.4–3.0 mm. Dark brown ground colour covered mostly with dense greyish-white pruinosity. Setae of body and legs white. Head (Fig. 33): Eyes with ommatrichia of lower third distinctly longer and slightly flattened, forming dense reflective mat of whitish coloured hair. Face tinged with faint golden pruinosity in most specimens, clypeus concolourous with greyish-white frons and vertex. Face narrowest at middle, about 2.0X width of anterior ocellus. Gena and postgena with moderately long white setae, forming short beard flanking mouthparts. Antenna (Fig. 44) including arista-like stylus, entirely dark brown; postpedicel elongate-conical, 1.75–1.8X longer than wide; arista-like stylus of medium length, about 1.4X length of postpedicel. Palpus with 7–8 setae on outer surface of apical half. Thorax: Mesoscutum with some brownishgrey pruinosity on dorsum. Acrostichal setulae quadriserial; 7–8 dorsocentral bristles, 0 presutural intra-alar bristles, 1–2 presutural supra-alar (posthumeral) bristles, 3–4 postsutural supra-alar bristles, 3 notopleural bristles. Scutellum with 3 pairs of bristles. Legs: Foreleg: Dark grey, pale at knee and apex of tibia, tarsomeres 1–2 pale yellowish-brown to brown, tarsomeres 3–5 brown to greyish-brown. Coxa with moderately long pale setae on anterior surface. Femur with numerous long setae on posterior surface, posterodorsal and posteroventral rows prominent. Tibia with short setae and setulae. Tarsus with setulae; tarsomeres 1–2 not dilated. Midleg: Dark grey, pale at knee and apex of tibia, tarsomere 1 pale yellowish-brown, tarsomeres 2–5 brown to greyish-brown. Femur with anteroventral rows of setae prominent. Tibia with pair of apicoventral bristles. Tarsomeres 1–4 each with pair of dark spine-like apicoventral setae. Hindleg (Figs 51, 54): Dark grey, femur dark brown posteriorly, pale at knee, tarsomere 1 and base of tarsomere 2 pale yellowish-brown, apex of tarsomere 2 and tarsomeres 3–5 brown to greyish-brown. Femur with ventral row of setae prominent. Tibia with anterodorsal and anteroventral rows of setae short to moderate length, shorter or subequal to width of tibia; anterodorsal row short, erect and comb-like. Tarsus slightly shorter than tibia with short setae and setulae; tarsomere 1 slightly shorter than combined length of tarsomeres 2–4; tarsomeres 1–4 with several short thick perpendicular peg-like setae dorsally, shortest on tarsomere 1; tarsomere 2 distinctly longer than tarsomere 3; tarsomere 3 longer than tarsomere 4; tarsomere 5 subequal in length to tarsomere 3. Wing (Fig. 64): Hyaline with dark brown veins. Cell dm produced apically, dmm crossvein concave. Vein CuA+CuP of medium length, straight. Abdomen (Figs 68–71): Tergites 2–4 with setae well-developed and relatively long. Sternite 5 with slender anteriorly curved digitiform pregenitalic process present, base with tiny anterior projection, apex blunt and covered with microtrichia, posterior edge of sternite 5 (behind process) deeply emarginate. Sternite 8 subquadrate with prominent elongate setae on posterolateral margins. Hypopygium (Figs 68–71, 78–79, 82, 97–98, 118): Large. Left epandrial lamella with ventral portion elongate (about 2X longer than high); ventral epandrial process broadly bifurcate, dorsal arm curved ventrally, narrow in middle portion, apex expanded and hook-like, ventral arm thick with minute apicodorsal seta 1–2 minute setae along distiventral margin, apex with expanded lamelliform concavity. Dorsal lobe of left surstylus with basiventral edge broadly rounded, apex narrow and pointed, with long basidorsal seta, shorter basilateral seta and long apical seta, medial surface with knob-like projection bearing lamelliform apical process. Ventral lobe of left surstylus shallowly bilobate in lateral view, dorsal lobe short with apex subquadrate, ventral lobe with rounded base bearing short lateral seta and complex upturned multilobate projection arising medioventrally. Right epandrial lamella with ventral epandrial process not developed; basal portion of epandrial lamella narrowed and dorsally curved, with deep dorsal emargination bordering ventral margin of right cercus. Dorsal lobe of right surstylus with 3 lateral setae (middle/lowermost seta weaker), apex narrowed with rounded tip bearing thick apically-frayed prensiseta on medial surface. Ventral lobe of right surstylus with lateral seta near middle, distal half recurved and tapered with tubercle bearing strong seta proximal to narrow medially pointed apex. Hypandrium very large, elongate-reniform with convex anterior and posterior ends extending to or beyond margins of epandrial lamellae in lateral view, bare. Left postgonite lobe rounded basally, constricted near middle, distal portion broadly lamelliform usually with claw-like apical process, base of lobe with slender medial projection. Right postgonite lobe with broad lateral protuberance and bump-like medial projection, apex bifurcate with short digitiform process and rounded lamelliform process. Phallus short and weakly curved, broad in basal 2/3 with apical 1/3 narrower (in lateral view), dorsal flange and left lateral dentiform projection present at 2/3 length. Ejaculatory apodeme broadly subtriangular. Hypoproct strongly projected dorsally as pair of slender blade-like lobes, right lobe with preapical ventral flange and piliferous region basally. Cerci with anal setae relatively short and not well-differentiated from surrounding well-developed hairs, medial margin of each cercus strongly produced dorsally; right cercus much larger than left cercus with basal portion distended and rounded laterally, apex strongly deflected dorsally at right angle, elongate, narrow and pointed, with 2 short apical setae present along lateral margin; left cercus oblong in dorsal view, apex strongly deflected dorsally at right angle, short and acute, with 2 long preapical setae on lateral margin.
Female: Body length 2.3–3.6 mm, wing length 2.2–3.2 mm. Similar to male except as follows: Head: Eyes with ommatrichia of nearly uniform length, not distinctly longer on lower third. Face not tinged with faint golden pruinosity, concolourous with greyish-white frons and vertex. Face wider, at middle about 3.5–4.0X width of anterior ocellus. Legs: Foreleg: Coxa with shorter more slender pale setae on anterior surface. Femur with posteroventral row of setae only prominent apically. Hindleg: Tibia with anterodorsal row slightly longer and less comb-like. Tarsomeres 1–4 without short thick peg-like setae dorsally. Abdomen: Tergite 5 broadly subtriangular to semicircular in dorsal view with posterior margin rounded (Fig. 131). Terminalia distinctly narrower than base of segment 5 (Figs 131–132); sternite 8 trough-like, lacking basal bulge, not distinctly narrowed apically, apical quarter rugose, apex truncate with margin somewhat irregular (Figs 130, 132, 137); sternite 9 reduced to narrow transverse sclerotized band; tergite 10 with hemitergites subtriangular and short, each with 2 acanthophorite spines; cercus short, pointed apically.
Distribution and seasonal occurrence. Parathalassius sinclairi is currently known to occur on sandy seashores of the Aleutian Islands and mainland Alaska, south along the coast of British Columbia, Washington and Oregon to the dunes near Florence in Lane County (Fig. 149). Adults have been collected from mid June to early September.
Etymology. This species is named in honour of our esteemed colleague and friend, Dr. Bradley J. Sinclair, who has contributed significantly to the systematic study of Empidoidea.
Remarks. The considerable COI barcode sequence data obtained from specimens of P. sinclairi from British Columbia, Washington and Oregon (Fig. 154) show very little genetic divergence (<1.1%), suggesting that there has been considerable gene exchange and possible movement between populations of this widely distributed species.
Parathalassius sinclairi has been taken in large numbers in several localities in both fore and back dune habitats (Figs 11–14).
description: Published as part of Cumming, Jeffrey M., 2017, Revision of the Nearctic Parathalassius Mik (Diptera: Dolichopodidae: Parathalassiinae), with a review of the world fauna, pp. 1-64 in Zootaxa 4314 (1) on pages 32-35, DOI: 10.11646/zootaxa.4314.1.1, http://zenodo.org/record/858378