Dasysyrphus pauxillus (Williston)
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|Dasysyrphus pauxillus (Williston)|
Figures: 14A–D, 18A & D, 21D
Synonyms and References:
Syrphus pauxillus Williston 1887: 74 (original description)
Fluke 1933: 115 (key, redescription and transfer to Metasyrphus )
Stone et al. 1965: 564 (catalogue and transfer to Dasysyrphus )
Vockeroth 1986: 203 (discussion)
Vockeroth 1992: 68 (key and redescription)
Speight 2011: 70 (discussion)
Diagnosis: Abdominal maculae of tergites 3&4 slightly arcuate, uniform in thickness and do not cross abdominal margin ( Figs 14A & B View FIGURE 14 ); very similar in appearance to D. pacificus ( Fig. 13A View FIGURE 13 ), D. nigricornis ( Figs 11A & B View FIGURE 11 ) and D. laticaudus ( Fig. 8A View FIGURE 8 ). Wing typically densely microtrichose, sometimes with bare areas in cells r 1, br, bm and/or c ( Fig. 14C View FIGURE 14 ). Male gonostylus with projection on posterodorsal surface straight ( Fig. 14D View FIGURE 14 ). Due to an extremely similar habitus, it is difficult to distinguish D. pacificus from D. pauxillus . Male genitalia should be used to conclusively identify specimens, especially in the overlap zone of these species’ ranges in southern British Columbia.
Body Length: 5.3–9.7mm; Wing Length: 5.2–9.5mm
Head: Frons dark with light pollenose fascia (in males it runs along ventral edge of where eyes meet, in females it is ⅓–½ the length between the antennae and ocelli with a separation medially and edges triangular to rounded ( Fig. 18A View FIGURE 18 )) and light to dark pile; face light with dark vitta ¼–⅓ the width of the face, coming close to antennal socket if not reaching it, face with dark pile lateral to the eye, some females with varying amounts of light pile interspersed with dark pile; gena with light to dark pile; occiput dark, covered in light pollen, pile light; scape and pedicel light to dark, flagellomere dark with lighter base.
Thorax: Scutum dark, may appear shiny or metallic, pile light to dark; scutellum light to dark with darker lateral edges, pile on female mostly light with some dark, male mostly dark pile some with light interspersed throughout; wing cell r 1 with the base bare or very small areas at base bare, br, bm and c may all be entirely microtrichose or they may have bare areas along spurious vein, along the middle of the cell form the base to ¾ or small areas at base, respectively ( Fig. 14C View FIGURE 14 ); haltere light; pro- and mesofemora ⅓–⅔ dark basally, ⅓–⅔ light apically, metafemur ⅔–¾ dark basally, ¼–⅓ light apically, tibiae light, meso- and metatibiae with dark band ¼ of the way from the apex, tarsi light with dark anterior side.
Abdomen: Maculae on tergite 2 large and oval, lateral edge tends to be more flattened than medial edge, female usually with very small, pointed, anterolateral projection, but it never reaches the edge of the tergite, maculae on tergites 3&4 are oblique, fairly straight and uniform in width, sometimes with medial edge slightly swollen, maculae do not reach abdominal margin ( Figs 14A & B View FIGURE 14 ); sternites light with dark fasciae of varying thickness ( Fig. 18D View FIGURE 18 ).
Male Genitalia: Surstylus more or less triangular in shape in lateral view, flattened posteriorly, long pile on dorsal, laterodorsal and posterodorsal sides, row of spines on posteromedial edge; cercus oval with long pile over entire surface; gonostylus boot-shaped but more narrow apically than basally, with projection on posterodorsal surface, projecting dorsally, pile on dorsal surface; basiphallus elongate, basally bent at a slightly more than 90 degree angle towards dorsum, apical end curved ventrally, but does not greatly extend ventrally and is partly membranous dorsally, with spines on posterodorsal side; distiphallus elongate, apical end flared out into horn, which is mostly sclerotized but membranous at apex, with no setulae dorsally, basally bent towards dorsum and usually greatly enlarged at bend with a triangular projection, projecting ventrally ( Fig. 14D View FIGURE 14 ). Extremely similar to D. laticaudus ( Fig. 8C View FIGURE 8 ).
Intraspecific variation: Wings are typically densely microtrichose with cell r 1 having bare areas at base ranging from entire base bare to very small areas at base being bare, cells br, bm and c may all be entirely microtrichose or they may have bare areas; female usually have a very small, anterolateral projection on maculae of tergite 2, males do not have this projection.
Etymology: From the Latin pauxillus , meaning small.
Distribution: Rocky Mountains; Western Canada (AB, BC, MB, YT) and western USA (AK, CO, ID, NM, UT, WY) ( Fig. 21D View FIGURE 21 ).
Ecology: Collected from March–July, but more commonly collected in June. Collected at elevations of 14– 3505m. Habitats collected from are listed as “moraine lake”, “grassy lakeshore”, “over stream in fir forest”, “on tundra”, “spruce forest” and “ Pinus-Salix forest”. It has been collected from the following plant species: common cow parsnip ( Heracleum maximum W. Bartram , Apiaceae ), blackberry ( Rubus Linnaeus , Rosaceae ), willow ( Salix Linnaeus , Salicaceae ), Canada gooseberry ( Ribes oxyacanthoides Linnaeus , Grossulariaceae ) and spruce ( Picea A. Dietrich , Pinaceae ).
Discussion: Many authors have used the name pauxillus in the Palaearctic. During the course of this revision few specimens from that region were examined and no DNA evidence could be studied. Therefore, we cannot comment on whether the use of this name is appropriate in the Palaearctic. However, based on the geographic breakdown of pauxillus and its allies ( laticaudus , pacificus and nigricornis ) in the Nearctic it seems likely that only nigricornis is Holarctic. European and Asian specimens should be studied in greater depth, using both morphology and DNA, to confirm this suspicion.
Due to the widespread use of the name pauxillus much confusion exists over the concept of this species. Many Holarctic species have been named which have an extremely similar habitus to pauxillus . The main reason for such confusion is that the holotype specimen is lost ( Fluke 1933). In Williston’s (1887) original designation he describes one female from New Mexico. He does not indicate where this specimen is deposited. The only other information that is provided is that the specimen was collected by G.F. Gaumer. In Fluke’s (1933) revision of Metasyrphus he indicates that he was unable to locate the type for examination. No record exists in the literature of any author examining Williston’s specimen; either Williston’s species description was used or specimens determined by other researchers were used for comparison. Dasysyrphus pauxillus was described in ‘Synopsis of the North American Syrphidae’, Williston’s PhD dissertation ( Beckemeyer 2009). The specimens from his dissertation were donated to the USNM ( Flint et al. 1976, F.C. Thompson, pers. comm.). According to Thompson (pers. comm.) the type specimen is not in the USNM collection today and it is not known what happened to it. Williston worked in Kansas and Chicago until his death, after which his collection was donated to the American Museum of Natural History (AMNH). Byers et al. ( Byers et al. 1962) do not list pauxillus as a type in the Kansas collection and the specimen is not listed in the type database of the AMNH (The American Museum of Natural History 2005). A neotype is designated here to bring stability to the name pauxillus . This will create a solid concept for this species, allowing for better reconciliation of closely related species. The specimen used in the original designation provided a locality of ‘New Mexico’. The neotype specimen was chosen from a series of males from Utah, as the two specimens from New Mexico were a female and a male in poor condition. This is a locality that is not overlapped by the other species with a similar habitus to pauxillus ( pacificus , laticaudus and nigricornis ). The neotype varies from Williston’s description in a few characters that are variable in many Dasysyrphus species. Also, Williston’s description was of a female and the neotype is male, which may account for some of the variation. The dorsum of the scutum in the neotype is covered by mainly dark pile, Williston’s description states the pile is light yellowish. This character is variable within most Dasysyrphus species and often males have more dark pile and females have more light pile on the scutum. The face is also not projecting to the extent described by Williston. The face seems to project slightly more in females than males, but in most specimens the distance between the antennae and the tip of the tubercle is more or less equal to the distance from the antennae to the ocelli. The specimen matches the description in all other characters. The Neotype is a male from Tony Grove Lake, Wasatch-Cache National Forest, UT, USA, collected on 1.vii.2010 by M.M. Locke. It is deposited in the CNC and databased with the number Jeff Skevington Specimen 24616.
Type Material: “ USA: UT:Wasatch-CacheNF:/ Tony Grove Lake;/ 41.893136°N, 111.641841°W;/ 1.vii.2010; M.M.Locke ”, “ J. Skevington / Specimen #/ 24616”, “ NEOTYPE / Syrphus / pauxillus/ Williston”, “designated by/ Locke &/ Skevington/ 2013”; ♂, deposited in the Canadian National Collection of Insects , Arachnids and Nematodes, Ottawa, Ontario GoogleMaps , Canada.
Canada: Alberta: WATERTON LAKES NATIONAL PARK : Waterton , [49.051122, -113.911807], 6.vi.1962, 2♂, CNCD 13764, 13765 GoogleMaps , 4♀, CNCD 13836–13839 GoogleMaps , W. R. M. Mason ( CNC), 2♀, CNCD 13834, 13835 , K.C. Herrmann ( CNC). KANANASKIS: 25 km WNW Bragg Creek Powderface trail Rd. , [51.02166667, -114.9016667], 8.vi.2001, ♂, RBCM ENT 6006051 View Materials GoogleMaps , C.J. Borkent ( RBCM); Forest Experimental Station Seebe , [51.100879, - 115.087692], 2.vi.1968, ♀, CNCD 13840 GoogleMaps , 13.vi.1968, ♀, CNCD 13841 GoogleMaps , 15.vi.1968, ♀, CNCD 13842 , H.J. Teskey ( CNC). 30 miles West of Calgary , [51.04575, -113.631333], 3.vi.1973, CNCD 60100 GoogleMaps , G.G.E. Scudder ( CNC). BANFF NATIONAL PARK : Banff , [51.180275, -115.568433], 27.v.1925, ♂, CNCD 13762 GoogleMaps , E. Hearle ( CNC); 2.vi.1922, ♂, CNCD 13763 , 3♀, CNCD 13845–13847 , 9.vi.1922, ♀, CNCD 13849 , 3.vii.1922, ♀, CNCD 13848 , C.B.D. Garrett ( CNC); 2.vi.1914, ♀, JSS 20605 View Materials , N.B. Sanson ( EMEC); 30.v.1948, ♀, UASM# 149024 View Materials , 2.vi.1948, ♀, UASM# 149025 View Materials , E.H. Strickland ( UASM); Mount Eisenhower , [51.298694, -115.925724], 3.vi.1968, 2♂, CNCD 13770, 13771 GoogleMaps , 5.vi.1968, ♂, CNCD 13769 GoogleMaps , 7.vi.1968, ♂, CNCD 13768 , Mosquin & Seaborn ( CNC); Moraine Lake , [51.324073, -116.184418], 2256m, 20.vii.1955, ♀, CNCD 13850 GoogleMaps , J. R. McGillis ( CNC); 8 km West of Lake Louise, [51.413684, -116.306046], 31.v.1992, ♀, JSS 20801 View Materials , A. Borkent ( CNC); Lake Agnes, [51.415101, -116.247314], 2073m, 10.vii.1925, ♂, JSS 19508 View Materials , O. Bryant ( CNC); Snow Creek Pass , [51.60524, -115.808617], 2256m, 20.vii.1962, ♀, CNCD 13844 GoogleMaps , K.C. Herrmann ( CNC); Peyto Lookout , [51.717631, -116.508919], 2316m, 23.vii.1962, ♀, CNCD 13843 GoogleMaps , W. R. M. Mason ( CNC). Edmonton, 12.v.1924, ♂, JSS 23724 View Materials , Owen Bryant ( CAS); Laggen , Lake Agnes , 10.vii.1925, ♀, JSS 23714 View Materials , O. Bryant ( CAS). Edmonton ; W. Hawrelak Park, 640m, 3.v.2005, 3♂, JSS 25540 View Materials –25542, W. van Steenis ( WVSC). Pincher Creek ; Beauvais Lake , 19.v.1989 23.v.1989, ♀, JSS 25550 View Materials , C. v. Nidek ( WVSC) . British Columbia: Victoria, Mt. Work, [48.53, -123.47], 26.v.1982, ♂, RBCM ENT 99188111 View Materials , R . A. Cannings ( RBCM). Galiano I. North End , [48.92, -123.42], 29.iii.1987, ♂, JSS 20184 View Materials , G.G.E. Scudder ( UBCZ). WATERTON LAKES NATIONAL PARK : Cameron Lake , [49.011457, -114.049238], 17.vi.1956, 9♂, CNCD 13754–13761, 13767 GoogleMaps , 9♀, CNCD 13822–13830 GoogleMaps , 18.vi.1956, ♀, CNCD 13831 , 19.vi.1956, 2♀, CNCD 13832, 13833 , E.E. Sterns ( CNC). CENTRAL KOOTENAY L.D.: Robson , [49.333015, -117.692871], 21.iv.1947, ♂, CNCD 13746 GoogleMaps , 8.v.1950, ♂, CNCD 13750 GoogleMaps , H. R. Foxlee ( CNC); 25.iv.1958, ♂, JSS 20123 View Materials , H. R . Foxlee ( UBCZ); Boswell , [49.414407, -116.746741], 9.v.1958, ♂, CNCD 13742 GoogleMaps , H. & A. Howden ( CNC). SQUAMISH- LILLOOET R . D.: Meager Creek Hot Springs , [50.561617, -123.486344], 14.v.1987, ♂, JSS 18370 View Materials , C.S. Guppy ( CNC). KOOTENAY NATIONAL PARK GoogleMaps : Daer-Pitts Aspen Control 1, [50.95, -116.0333333], 3.vi.2000 17.vi.2000, CNCD 7969 , G. Gareau ( CNC); Daer-Pitts Aspen Control 2, 17.vi.2000 2.vii.2000, ♀, CNCD 30906 , G. Gareau ( CNC). 32 miles South West of Terrace , [54.194076, -129.140296], 30.5m, 6.vi.1960, ♀, CNCD 13819 GoogleMaps , G.E. Shewell ( CNC); 6.vi.1960, ♀, CNCD 13820 , 11.vi.1960, ♂, CNCD 13753 , B. Heming ( CNC). Shames, 18 Miles South West of Terrace , [54.409648, -128.935301], 23.vi.1960, ♀, CNCD 13818 GoogleMaps , C. H. Mann ( CNC). Kleanza Creek, Near Terrace , [54.597897, -128.386241], 76.2m, 29.vi.1960, ♀, CNCD 13817 GoogleMaps , B. Heming ( CNC); 30.vi.1960, ♀, CNCD 13821 , J.G. Chillcott ( CNC). Atlin , [59.5775, -133.69236], 670.56m, 2.vi.1955, ♂, CNCD 13751 GoogleMaps ,. vii.1955, ♀, CNCD 13809 GoogleMaps , H.J. Huckel ( CNC); 20.vi.1955, ♂, CNCD 14358 , ♀, CNCD 13808 , B.A. Gibbard ( CNC) . Manitoba: 26km SE Churchill; Twin Lakes , [58.63, -93.819], 14m, 19.vii.2009, ♀, 09 PROBE 197 , 22.vii.2009, ♂, 09 PROBE 255 , Arctic Ecology 2009 ( CNC) . Yukon Territory: Snafu Creekl , [60.13333333, -138.8], 22.vi.1982, CNCD 60079 , S.G. Cannings, R . D. Wilkie, L. Vasington ( CNC). Whitehorse , [60.71965, -135.052213], 6.vii.1988, ♀, CNCD 5812 GoogleMaps , F. Brodo ( CNC). Simpson L. 81 km n Watson L., [60.75, -129.25], 15.vi.1984 1.ix.1984, ♀, JSS 20770 View Materials , S. & J. Peck ( CNC). Nines Creek , 3 km West of Alaska Highway, [61.18333333, -139.7], 4.vi.1981, CNCD 60072 , C. Guppy ( CNC). La Force Lake , [62.683333, -132.333333], 914m, 26.vi.1960, ♀, CNCD 13585 GoogleMaps , 10.vii.1960, ♀, CNCD 13728 GoogleMaps , E.W. Rockburne ( CNC) . United States of America: Alaska: MATANUSKA- SUSITNA CO .: Matanuska , [61.541945, -149.229674], 12.vi.1944, ♀, JSS 19502 View Materials , J. Chamberlin ( CNC) GoogleMaps . Colorado: Rocky Gulch, [37.817035, -107.579606], 3444m, 6.xxii.2002, ♂, JSS 20810 View Materials , C. Slater ( CSUC). Monarch Pass , 2mi W Garfield, [38.501433, -106.327747], 3048m, 19.vi.1985, ♂, USNM ENT 258074 View Materials GoogleMaps , David R . Smith ( USNM). Rock Cr., May Mus. , [38.705655, -104.837421], 8.v.1996, ♀, JSS 20808 View Materials , D. Leatherman ( CSUC). Tenmile Range , unamed Cr. avalanche chute W side, [39.425, -106.111], 3200m, 15.vii.1998 17.vii.1998, ♂, JSS 20694 View Materials , S. Fitzgerald & A. Foley ( CSUC). CLEAR CREEK CO GoogleMaps .: Mt. Evans, Echo Lake Campground , [39.65622, 105.595042], 329m, 29.vi.2010, CNCD 60035 GoogleMaps , M.M. Locke ( CNC); Mt. Evans, Echo Lake , [39.658085, - 105.6035], 3231m, 13.vii.1961, ♀, CNCD 26416 GoogleMaps , C.H. Mann ( CNC); 29.vi.2010, ♀, JSS 24618 View Materials , M.M. Locke ( CNC); 29.vi.2010, ♀, CNCD 35312 , A. Young ( CNC); Mt. Evans, Doolittle Ranch , [39.675739, -105.601348], 2987m, 13.vii.1961, ♀, CNCD 26417 GoogleMaps , W. R. M. Mason ( CNC). BOULDER CO .: Nederland, Science Lodge , [40.031645, -105.533886], 2896m, 4.vii.1961, ♀, CNCD 26418 GoogleMaps , B.H. Poole ( CNC); Niwot Ridge, Near Ward , [40.069933, -105.607397], 3444m, 4.vi.1961, ♂, CNCD 26440 GoogleMaps , 28.vi.1961, ♂, CNCD 26439 GoogleMaps , C.H. Mann ( CNC). North Park, [40.73, -106.18], 1.vii.1932, ♀, JSS 20746 View Materials , ( CSUC). Rawah Wilderness, Blue Lake Trail near Fall Creek , [40.76944444, -105.9894444], 2926m, 20.vi.1998, ♂, JSS 20693 View Materials , S. Fitzgerald & A. Foley ( CSUC). Cherokee Park, [40.90972, -105.47917], 30.vii.1913, ♀, JSS 20713 View Materials , Chas L. Fluke ( CSUC). MINERAL CO GoogleMaps .: Continental Divide, 3292m, 20.vi.1919, ♂, JSS 19512 View Materials , ( CNC). Camera Point, Pike’s Peak , 16.vi.1956, ♀, JSS 21157 View Materials , R . & K. Dreisbach ( MSUC) . Idaho: Island Park , [44.424364, -111.371064], JSS 25099 View Materials , Bernard Knapp ( EMUS). NEZ PERCE CO GoogleMaps .: Lake Waha , [46.205942, -116.837015], 9.vi.1918, ♀, CNCD 26402 GoogleMaps , A.L. Melander ( CNC); 18.vi.1930, ♂, JSS 19514 View Materials , W.M. Davidson ( CNC); Waha , [46.211439, -116.844439], 18.vi.1909, ♀, JSS 19501 View Materials , ( CNC); 30.v.1924, ♀, JSS 23778 View Materials , A.L. Melander ( USNM). LATAH CO GoogleMaps .: Moscow Mt., [46.800972, - 116.866093], 8.vi.1921, ♀, JSS 23776 View Materials , 26.vi.1922, ♀, JSS 23777 View Materials , A.L. Melander ( USNM); Mountains Near Moscow , Latah County, [46.807258, -116.868969], 1.vi.1907, ♀, CNCD 26403, ( CNC); 17.vi.1918, ♂, JSS 19509 View Materials , 26.vi.1920, ♂, JSS 19506 View Materials , 9.vii.1920, ♀, JSS 19505 View Materials , A.L. Melander ( CNC); vii.1910, ♀, JSS 19510 View Materials , 25.vi.1920, ♂, JSS 19516 View Materials , R GoogleMaps . C. Shannon ( CNC). Savary , 29.iv.1916, ♀, JSS 21329 View Materials , ( MCZ) . New Mexico: Las Cruces, Dona Ana , [32.3, -106.7666667], ♀, CNCD 26423 , F.M. Hull ( CNC). LINCOLN CO ., Sierra Blanca , [33.478065, - 105.552907], 2957m, 10–26.vi.1979, ♂, JSS 18307 View Materials , S. & J. Peck ( CNC). SAN MIGUEL CO GoogleMaps ., Santa Fe National Forest , [35.705996, -105.545731], 27.v.1981, ♀, JSS 18346 View Materials , B.J. Sinclair ( CNC). SANDOVAL CO GoogleMaps .: Jemez Springs , [35.771336, -106.690555], iv, ♀, CNCD 26422, ( CNC) GoogleMaps . Utah: WASATCH CO .: Daniels Pass , 2 miles South, [40.280034, -111.223675], 2591m, 9.vii.1961, ♀, CNCD 26421 GoogleMaps , J.G. Chillcott ( CNC). DUSCHENE CO .: 2 miles West of Mirror Lake , [40.70363, -110.928511], 23.vi.1968, ♂, CNCD 26438 GoogleMaps , B. V. Peterson ( CNC). CACHE CO .: Card Canyon , [41.76236, -111.663482], 13.vi.1937, ♀, CNCD 26420 GoogleMaps , A.E. Nye ( CNC); Cowley Canyon, [41.772669, -111.60407], 13–27.v.1989, ♂, JSS 24612 View Materials , W.J. Hanson ( EMUS); Tony Grove Lake , [41.893136, - 111.641841], 1.vii.2010, CNCD 60037–60040 GoogleMaps , ♂, JSS 24615 View Materials , M.M. Locke ( CNC); West Hodges Canyon, [41.910305, -111.42277], 13–20.vi.1980, JSS 25096 View Materials , ( EMUS); Left Hand Fork, Blacksmith Fork Canyon , 24.v.2004, ♀, JSS 24617 View Materials , Brammer ( EMUS). RICH CO GoogleMaps .: Logan Canyon Summit , [41.862735, -111.494404], 26.vi.–2.vii.1982, JSS 25098 View Materials , ( EMUS) GoogleMaps . Wyoming: YELLOWSTONE NATIONAL PARK GoogleMaps : Lewis Lake , [44.306126, - 110.537673], 17.vii.1923, ♀, JSS 19500 View Materials , A.L. Melander ( CNC); 17.vii.1923, ♀, JSS 23774 View Materials , A.L. Melander ( USNM) GoogleMaps .
University of Tehran
Departamento de Geologia, Universidad de Chile
Canadian National Collection of Insects, Arachnids, and Nematodes
Royal British Columbia Museum
Essig Museum of Entomology
University of Alberta, E.H. Strickland Entomological Museum
California Academy of Sciences
University of British Columbia, Spencer Museum
Museum National d'Histoire Naturelle
California State University, Chico, Vertebrate Museum
Smithsonian Institution, National Museum of Natural History
Museum, Zoology Department, University of New England
Museum of Comparative Zoology
Royal British Columbia Museum - Herbarium
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