Gimnomera subvittata (Malloch)

Chagnon, Marie-Eve & Sinclair, Bradley J., 2020, Revision of the Nearctic species of Gimnomera Rondani (Diptera: Scathophagidae) with morphological phylogeny and DNA barcodes, Zootaxa 4853 (3), pp. 369-403 : 383-385

Gimnomera subvittata (Malloch)

( Figs 9, 10 , 17 , 29 , 35 )

Cordylurella subvittata Malloch, 1919: 78 . Type locality: Bernard Harbour, Nunavut, Canada.

Gimnomera subvittata: Vockeroth, 1965: 840 (new combination).

Diagnosis. This Nearctic species is characterized by a yellow postpedicel, pedicel and scape, a unique character in the genus, as well as its male terminalia with truncate apical projections and lateral protrusions on the cercus as well as a branched pregonite. Other similar Nearctic species are G. aquilonia , G. cuneiventris and G. tibialis , and can be distinguished by the shape of the male cercus and pregonite: cup-shaped cercus and unbranched pregonite in G. aquilonia ; tapered apical projection on cercus and tear-dropped shaped pregonite with two setae in G. tibialis ; G. subvittata is distinguishable from G. cuneiventris by having two dorsocentral setae (one in G. cuneiventris ) as well as the male terminalia.

Redescription. Male. Body: Primarily brown to black ( Fig. 17 ); pleura brown to black; scutum black; entire body glossy, excluding anterior part of scutum, pruinose stripe down acrostichal row. Head with face yellow and gena yellow sometimes with brown stripe in genal groove; genal width less than 1⁄2 eye height; postgena brown. Frontal vitta yellow; fronto-orbital plate black with yellow anteriorly; parafacial yellow. Fronto-orbital plate with 3 inclinate frontal setae, 2 lateroclinate orbital setae, 1 pair of lateroclinate ocellar setae, 1 pair of short postocellar setae; 1 long inclinate inner vertical seta, 1 lateroclinate outer vertical seta. Gena with no supravibrissal setae; 1 strong vibrissa; 3–6 variably lengthened subvibrissal setae. Antenna with postpedicel yellow, about twice as long as pedicel; scape and pedicel yellow, pedicel with 3 stout setae along ptilinal fissure; arista black and micropubescent. Palpus yellow, with black setulae apically. Thorax with scutal setae black; acrostichal setae biserial, finer and paler than dorsocentrals; 1 presutural and 1 postsutural dorsocentral seta; 1 posterior postpronotal seta and two rows of 8–10 short, stout erect postpronotal setae on anterior margin of postpronotum and scutum, anterior setae variable in thickness; 1 presutural intra-alar seta, 2 notopleural setae, without postsutural intra-alar setae, 2 postsutural supraalar setae, 2 postalar setae. Pleura with 1 proepisternal seta; 1 proepimeral seta; 1–2 posterior anepisternal setae and 4 long, pale anepisternal setulae; 1 posterodorsal katepisternal seta; anepisternum, katepisternum and anepimeron pruinose. Wing (length 3.2–3.4 mm) clear, infuscate; R 1 with singular row of 0–3 black setulae on marginal part of vein above; CuA+CuP ends more than half way to wing margin. Halter brown. Legs entirely yellow, mid and hind coxa brown, tarsi darken to brown. Fore femur with 2 dorsal setae on apical 1⁄2. Fore tibia with 1 medial posterodorsal seta; 1 mid dorsal seta; 1 preapical dorsal seta and 1 preapical posteroventral seta. Mid femur with 5 anterodorsal setae on apical 1⁄2 and 1 preapical posteroventral seta. Mid tibia with 1 preapical posteroventral seta. Hind femur with 1 mid dorsal seta and 1 preapical anterodorsal seta. Hind tibia with 1 mid anterior seta. Setulae short and clear. Abdominal tergites black, clothed with pale setulae; sternites black. Sternite 5 with pair of rounded lobes with crown of stout setae ( Fig. 29 ). Terminalia ( Figs 9, 10 ) with epandrium black; surstylus brown; cercus black; hypandrium brown. Surstylus longer than cercus; shallow trough-shaped with indent facing cercus. Cercus spade-shaped, fused apically; lateral protrusions pointed rather than rounded. Pregonite branched into 2 subequal lobes, division between branches shallower than in G. incisurata and G. terrywheeleri ; dorsal branch with 3 thick black setae; ventral branch with 1 thick black seta. Postgonite positioned dorsally to pregonite and apical end curved ventrally; tapered to point.

Female. Similar to male; terminalia as described in generic diagnosis; intersegmental membrane between 7 and 8 clothed with short fine spines.

Type material examined. HOLOTYPE ♂, labelled: “Type/ Cordylurella / subvittata/ Mall./ No. 1188 [red label]”; “Bernard/ Harbour/ N.W. T./ July 18-19”; “Canadian/ Arctic/ Expedition/ F.J. 1915”; “1291” ( CNC).

Additional material examined. CANADA. British Columbia: Summit Lake, Alaska Hwy [58°38′59.63′′N 124°38′00.23′′W], 2–4.vii.1959, E.E. MacDougall (1♂, CNC) . Northwest Territories: Holman [70°44′07.2′′N 117°45′44.6′′W], 25–27.vi.1988, J. Troubridge (2♀, 7♂, DEBU) ; Masik River , Banks Is. [71°35′24.8′′N 123°24′58.7′′W], 3–29.vii.1968, W. R. M. Mason (9♀, 27♂, CNC) ; Masik River , Banks Is. [71°35′24.8′′N 123°24′58.7′′W], 30–31.vii.1968, G.E. Shewell (3♂, CNC) ; Reindeer Depot, Mackenzie Delta [65°17′35.0′′N 126°18′51.3′′W], 23.vi.1948, W.J. Brown (1♂, CNC) ; Reindeer Depot, Mackenzie Delta [65°17′35.0′′N 126°18′51.3′′W], 24.vi.1948, J. R. Vockeroth (1♀, CNC) ; same data except, 5.vii.1948 (1♂, CNC) ; Tuktoyaktuk [69°26′43.0′′N 133°01′52.7′′W], 17–25.vi.1971, D.M. Wood (1♀, 1 ♂, CNC) ; Victoria Is. , 71°17′N 114°W, 1– 5.vii.1975, G. & M. Wood (3♀, 10♂, CNC) ; same data except, 8–15.vii.1975 (5♀, 10♂, LEM; 1♂, CNC) ; same data except, 23–28.vii.1975 (1♀, 1♂, CNC) . Nunavut: Cambridge Bay [69°07′05.0′′N 105°03′26.1′′W], 14–22.vii.1950, E.H.N. Smith (12♀, 22♂, CNC) ; Cambridge Bay [69°07′05.0′′N 105°03′26.1′′W], 20–26.vii.1950, G.K. Sweatman (14♀, 19♂, CNC; 1♂, DEBU) ; same data except, 2.viii.1950 (3♀, 1♂, CNC) ; same data except, 7.viii.1950 (1♂, CNC) ; Cambridge Bay [69°07′05.0′′N 105°03′26.1′′W], 28.vii.1950, E.H.N Smith (1♀, 3♂, CNC) ; same data except, 3.viii.1950 (1♀, CNC) ; Cambridge Bay [69°07′05.0′′N 105°03′26.1′′W], 12.viii.1959, W. R. M. Mason (1♀, CNC) ; same data except, W. R. Richards (1♂, CNC) ; Cambridge Bay , 69°7′11.748′′N 105°25′14.34′′W, Rep. 1 msic, pan traps / Malaise, 7–11.vii.2011, NBP field party (1♂, LEM) ; same data (1♀, 1♂, barcoded, LEM) ; same data except, 69°7′14.52′′N 105°25′32.952′′W, Rep. 2 mesic, pan traps / Malaise, 11–15.vii.2011 (3♂, LEM) ; same data (2♀, 1 ♂, barcoded, LEM) ; same data except, 69°7′11.748′′N 105°25′14.34′′W (1♂, LEM) ; same data except, 69°7′17.652′′N 105°25′52.464′′W, Repl. 3 mesic, pan traps / Malaise, 15–19.vii.2011 (2♀, LEM) ; same data except, 69°7′14.52′′N 105°25′32.952′′W, Repl. 2 mesic, pan traps, (2♀, LEM) ; Coral Harbour [64°08′30.9′′N 83°10′50.5′′W], 15–16.vii.1959, W. R. M. Mason (2♂, CNC) . Québec: Fort Chimo [58°06′10.8′′N 68°25′08.6′′W], 2.vii.1954, J.F. McAlpine (1♀, CNC) ; Payne Bay [60°01′43.7′′N 69°50′33.4′′W], 29.vii.1958, E.E. MacDougall (1♀, CNC) ; Payne Bay [60°01′43.7′′N 69°50′33.4′′W], 8–10.vii.1958, W. R. M. Mason (1♀, 3♂, CNC) . Yukon: Dempster Hwy, nr North Fork Pass , 69°35′50.496′′N 138°18′36.324′′W, Repl. 2 wet, Malaise, 1180 m, 24–27.vii.2011, NBP Field Party (1♀, LEM) ; same data except, 64°36′20.16′′N 138°21′41.148′′W, Repl. 1 mesic, Malaise, 1190 m, 21–24.vi.2011 (1♀, LEM) ; Herschel [69°34′N 138°52′W], 4–10.vii.1953, J.S. Waterhouse (2♀, 4♂, CNC) ; Herschel [69°34′N 138°52′W], 28–19.vii.1971, D.M. Wood (4♀, 5♂, CNC) ; Richardson Mts , 66°27′N 138°35′W, 8.vii.1982, M. Wood (1♀, CNC) . USA. Alaska: Richard Hwy , mile 213 [64°12′27.6′′N 145°42′46.7′′W], 17.vi.1951, W. R. M. Mason (1♂, CNC) ; Unalakleet [63°52′22.7′′N 160°47′18.9′′W], 15–18.vi.1961, B.S. Heming (3♀, 2♂, CNC) .

Distribution. This species ranges from the sub to high arctic, across the continent with a population in northern British Columbia ( Fig. 35 ).

Gimnomera terrywheeleri sp. nov.

( Figs 11, 12 , 27 , 36 )

urn:lsid:zoobank.org:act:21167A77-0769-4F65-9EC3-73678A0BB386

Diagnosis. This Nearctic species is characterized by the anterior margin of the scutum and postpronotum with light coloured setulae and the male terminalia with its rectangular-shaped cercus with lateral protrusions. Gimnomera terrywheeleri is similar in appearance to the Nearctic species G. cerea and G. incisurata because of similarities in body colour, but G. cerea can be distinguished from G. terrywheeleri by the spine-like setae along the anterior margin of the scutum and postpronotum. Gimnomera incisurata can be distinguished by the pale coloured pedicel. Gimnomera terrywheeleri is also similar to G. vockerothi but can be distinguished by a rectangular-shaped cercus with flap-like apical projection.

Description. Male. Body: Primarily yellow; pleura yellow; scutum yellow; entire body matte (not glossy). Head with face and gena black or yellow; genal width about 1⁄2 eye height; postgena yellow. Frontal vitta black to ocellar triangle; fronto-orbital plate black, browner towards ocellar triangle; parafacial black. Fronto-orbital plate with 2 inclinate frontal setae, 1 proclinate and 2 lateroclinate orbital setae, 1 pair of lateroclinate ocellar setae, 1 pair of divergent postocellar setae subequal in length to ocellar setae, 1 pair of inclinate paravertical setae, 1 long inclinate inner vertical seta, 1 long lateroclinate outer vertical seta. Gena with 2 supravibrissal setae; 1 strong vibrissa; 6–8 variably lengthened subvibrissal setae, 1 subequal to vibrissa. Antenna with postpedicel black, about twice as long as pedicel; scape and pedicel black, pedicel with 1 stout seta along ptilinal fissure; arista black and pubescent. Palpus black, clothed with black setae. Thorax with scutal setae dark golden; acrostichal setae biserial, finer and paler than dorsocentrals; 3 presutural and 3 postsutural dorsocentral setae with 2 finer setulae between each seta; 2 posterior postpronotal setae and two rows of 8–10 short, fine yellow anterior postpronotal setae, anterior setae variable in thickness ( Fig. 27 ); 1 presutural intra-alar seta, 2 notopleural setae, 1 postsutural intra-alar seta, 2 postsutural supra-alar setae, 2 postalar setae. Pleura with 1 yellow proepisternal seta, 1 yellow proepimeral seta; 2 brown posterior anepisternal setae and several long anepisternal setulae, all yellow; 1 posterodorsal katepisternal seta; anterior half of anepisternum and anepimeron bare; katepisternum with setulae ventrally. Wing (length 3.56–4.00 mm) clear, lightly infuscate; R 1 with singular row of 11–13 setulae on entire R 1 above; CuA+CuP ends just before wing margin. Halter yellow. Legs entirely yellow. Fore femur with long, white ventral pile; 2 posterodorsal on apical 1⁄3 and 1 posterodorsal on basal 1⁄3. Fore tibia with 1 preapical dorsal and 1 mid dorsal; 1 mid posterodorsal seta slightly higher than mid dorsal seta; 1 preapical posterior and 1 mid posterior seta at same level as mid dorsal seta. Mid femur with 1 preapical dorsal seta; 1 preapical posterodorsal seta; 2 anterior setae on apical 1⁄3 and 1 mid anterodorsal seta. Mid tibia with 1 preapical dorsal and 1 dorsal seta on basal 1⁄3; 1 preapical anterodorsal and 1 mid anterodorsal seta; 1 preapical ventral seta. Hind femur with 6 anterodorsal and 3 anteroventral setae. Hind tibia with 1 preapical dorsal seta; 1 preapical anterodorsal seta; 1 preapical posterodorsal seta; 1 preapical anterior seta; 1 preapical anteroventral seta; 2 anterodorsal setae on basal 1⁄2 and 1 dorsal seta on basal 1⁄3. Tarsi with black ventral pile. Abdominal tergites yellow. Abdominal sternites yellow. Sternite 5 as in Figure 29 . Terminalia ( Figs 11, 12 ) with epandrium yellow; surstylus yellow with apical ends black; cercus yellow; hypandrium yellow. Surstylus longer than cercus, meeting below cercus; uniform in shape with round pointed apex. Cercus rectangular in shape, fused apically; lateral margin jagged and uneven with small lobe protruding laterally near ventral end; setae clothed evenly over surface. Pregonite branched into 2 subequal lobes; anterior branch with 2 long, thick setae; posterior branch with 4 long, thick setae. Postgonite positioned posteriorly to pregonite and apical end curved anteriorly.

Female. Similar to male, except head with face and gena yellow; postgena darker yellow than gena. Frontal vitta darker yellow than fronto-orbital plate; fronto-orbital plate yellow and parafacial yellow. Gena with 4–5 variably lengthened subvibrissal setae. Terminalia as described in generic diagnosis; membrane between tergites and sternites 7 and 8 with short, pale spines.

Type material. HOLOTYPE ♂, labelled: “USA: CO [Colorado]: Archuleta Co.,/ Elk Crk , 7109 ft, 37°16′21′′N / 107°20′11′′W, 17.vi.2017 / S.E. Brooks, CNC856714 ”; “ HOLOTYPE / Gimnomera / terrywheeleri / Chagnon & Sinclair [red label]” ( CNC) . PARATYPES: USA. Colorado: same data as holotype (1♂, CNC) ; Archuleta Co., Horse Ck , 7447 ft, 37°17′52′′N 107°19′57′′W, 17.vi.2017, S.H. Cumming (1♂, CNC) ; Chaffee Co., 38°33′15′′N 106°13′38′′W, 15.vi.2017, J.M. Cumming (1♀, CNC) ; Estes Park [40°22′38.5′′N 105°31′17.3′′W], 2.vii.1961, C.H. Mann (1♂, CNC) ; same data except, W. R. Mason (1♀, 1♂, CNC) ; Fremont Co. [38°29′16.7′′N 105°26′27.3′′W], 19.vi.1988, R. Wharton (1♂, CNC) ; Hinsdale Co., 38°10′56′′N 107°18′18′′W, 15.vi.2017, S.H. Cumming (1♀, CNC) ; Summit Co., Frisco, N Tenmile Ck , 9248 ft, 39°34′31′′N 106°7′5′′W, 13–22.vi.2017, Malaise trap, J.M. Cumming, S.E. Brooks (1♀, 3♂, CNC) . Idaho: Lake Waha [46°12′41.1′′N 116°50′25.0′′W], 9.vi.1918, A.L. Melander (1♂, USNM) . Utah: Unita NF, E Vivian Park , 40°20′51.684′′N 111°32′52.692′′W, 8.vi.2011, B.J. Sinclair (2♂, barcoded, CNC) .

Distribution. This species is found in the western Cordillera of the USA (Colorado, Idaho and Utah) ( Fig. 36 ).

Etymology. This species is named after Terry Wheeler of McGill University, who had a significant influence on the senior author’s academic life. He was one of the primary supervisors for the senior author up until his death in the summer of 2017.

Figures

FIGURES 9–12. Gimnomera male terminalia, posterior and lateral views. 9–10. G. subvittata (Malloch); 11–12. G. terrywheeleri sp. nov. Abbreviations: cerc—cercus; epand—epandrium; hypd—hypandrium; pregt—pregonite; sur—surstylus.

FIGURES 17–20. Male and female Gimnomera, lateral views. 17. G. subvittata (Malloch), male; 18. Female of possible ninth species of Nearctic Gimnomera (Gimnomera sp. A); 19. G. tibialis (Malloch), female; 20. G. vockerothi sp. nov., female.

FIGURES 26–30. Morphological features of Gimnomera. 26–27. View of anterior margin of postpronotum with dark spine-like setae or with light coloured setulae: 26. G. cerea (Coquillett); 27. G. terrywheeleri sp. nov.; 28. G. tibialis (Malloch), vein R1 with row of setulae; 29–30. Male sternite 5: 29. G. subvittata (Malloch); 30. G. vockerothi sp. nov..

FIGURES 35–36. Known distribution of Gimnomera. 35. G. subvittata (Malloch); 36. G. terrywheeleri sp. nov.