Dasysyrphus occidualis Locke & Skevington

Locke, Michelle M. & Skevington, Jeffrey H., 2013, Revision of Nearctic <i> Dasysyrphus </ i> Enderlein (Diptera: Syrphidae), Zootaxa 3660 (1), pp. 1-80: 52-54

publication ID

http://dx.doi.org/10.11646/zootaxa.3660.1.1

publication LSID

lsid:zoobank.org:pub:95ADD39C-98BE-4879-B070-34A5D86BD67B

persistent identifier

http://treatment.plazi.org/id/03893F32-FF80-FF97-FF46-FF70FF7A8C08

treatment provided by

Felipe

scientific name

Dasysyrphus occidualis Locke & Skevington
status

sp. nov.

Dasysyrphus occidualis Locke & Skevington   sp. nov.

Figures: 12A–E, 21B

Synonyms and References:

Syrphus amalopis Osten Sacken   :

Williston 1887: 69 (in part; description)

Metasyrphus amalopis   :

Fluke 1933: 110 (in part; key and redescription)

Dasysyrphus amalopis   :

Stone et al. 1965: 563 (in part; catalogue)

Vockeroth 1992: 63 (in part; key and redescription)

Diagnosis: Abdominal maculae do not meet abdominal margin; maculae on tergites 3&4 are constricted medially and are either divided or not ( Figs 12A–C View FIGURE 12 ). Wings cell br usually with a small bare area above base of spurious vein ( Fig. 12E View FIGURE 12 ). Surstylus with a prominent posterolateral edge ( Fig. 12D View FIGURE 12 ). Similar to D. amalopis   , but D. amalopis   has maculae on tergites 3&4 usually undivided ( Fig. 5A View FIGURE 5 ), cell br densely microtrichose and does not have a prominent posterolateral edge on the surstylus ( Fig. 5C View FIGURE 5 ). Male genitalia should be used to reliably differentiate between these two species. There is a range of overlap in southern Yukon where it may not be possible to distinguish between females of these two species due to variations in the aforementioned characters.

Description:

Body Length: 8.0– 11mm; Wing Length: 7.2–10.7mm

Head: Frons dark with light pollenose fascia (in males it runs along ventral edge of where eyes meet, in females it is continuous, ⅓–½ the length between the antennae and ocelli) with dark pile; face light with dark vitta <¼–⅓ the width of the face, usually not reaching antennal socket, if it does then narrowly so, face with dark pile; gena dark with dark pile ventral to the eye and light pile elsewhere; occiput dark, covered in light pollen, pile light; scape, pedicel and flagellomere dark.

Thorax: Scutum dark, may appear shiny or metallic, pile light anteriorly and dark posteriorly (amount varies); scutellum light to dark with darker lateral edges, some light pile along anterior edge and dark pile elsewhere; wing densely microtrichose, cell br usually with small bare areas at above base of spurious vein, r 1 sometimes bare at base and cup sometimes bare in areas along vein CuP ( Fig. 12E View FIGURE 12 ); haltere light; pro- and mesofemora ½–¾ dark basially, ¼–½ light apically, metafemur ¾ dark basially, ¼ light apically, tibiae variable from all light to slightly darkened apically to ¾ dark apically, tarsi light with dark anterior side to all dark.

Abdomen: Maculae on tergite 2 large, ⅓–<½ the width of tergite 2, and oval with constriction medially (sometimes just slight constriction), maculae on tergites 3&4 are oblique and constricted medially, usually completely dividing maculae into four spots, if not completely divided then maculae on tergite 4 usually more constricted that on tergite three and almost divided, maculae do not reach abdominal margin ( Figs 12A–C View FIGURE 12 ); sternite 2 is light with a dark triangular to straight macula connecting with the lateral edges of the sternite, sternites 3 & 4 are light with dark fasciae of varying thickness.

Male Genitalia: Surstylus more or less triangular in shape in lateral view, flattened posteriorly with prominent posterolateral edge, 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 with pointed projection on posterodorsal surface that projects dorsally, pile on dorsal surface; basiphallus elongate, basally bent at about a 135 degree angle towards the anterodorsum, apical end curved ventrally with a widened apex and is partly membranous dorsally, with spines on posterodorsal side, apex; distiphallus elongate, apical end flared out into horn, which is mostly sclerotized but membranous at apex with minute setulae dorsally, basally bent towards dorsum and enlarged ventrally at bend ( Fig. 12D View FIGURE 12 ).

Intraspecific variation: The maculae on tergites 3 & 4 are often divided ( Fig. 12B View FIGURE 12 ). If not completely divided then maculae on tergite 4 usually more constricted that on tergite three and almost divided. Can have maculae on tergites 3 & 4 entire, but this less common ( Fig. 12A View FIGURE 12 ). Wing densely microtrichose, except for cell br, which is usually bare above base of spurious vein, sometimes only in very tiny areas with one or two microtrichia missing, r 1 sometimes bare of microtrichia at base and cup sometimes bare in areas along vein CuP ( Fig 12E View FIGURE 12 ).

Etymology: From the Latin occidualis   , meaning western.

Distribution: Western Canada (AB, BC, YT) and western USA (AK, CO, WA, WY) ( Fig. 21B View FIGURE 21 ).

Ecology: Collected from May–August, but more frequently collected in July. Collected at elevations of 613– 3658m. Habitats listed on labels include “outlet marsh”, “sedge fen” and “subalpine”.

Discussion: Until now, D. occidualis   has been hidden within D. amalopis   . With an absence of distinguishing external morphological characters, additional data were necessary to illuminate cryptic species such as this. In this study, COI DNA first highlighted the existence of two distinctly different genetic clusters within amalopis   . Upon further inspection of the specimens, the male genitalia showed a prominent posterolateral edge on the surstylus ( Fig. 12D View FIGURE 12 ), which amalopis   does not have ( Fig. 5C View FIGURE 5 ). When their geographic ranges were studied it was found that specimens of occidualis   were only located in western Canada and the US (from Alaska to Colorado), while amalopis   was found only in northern Canada. There is an overlap zone in southern Yukon so specimens in this area must be carefully studied to make the correct species determination.

Type Material: “ USA: WA: Mt. Baker-/ Snoqualmie NF: Mt. Baker :/ SilverFirCampground; 2012ft. / 48.904950°N, 121.697917°W;/ 8.vii.2010; M.M.Locke ”, “ J. Skevington / Specimen #/ 23708”, “ HOLOTYPE / Dasysyrphus   / occidualis/ Locke &/ Skevington”, ♂, deposited in the Canadian Collection if Insects, Arachnids and Nematodes ( CNC), Ottawa, Ontario GoogleMaps   , Canada.

Material Examined:

Canada: Alberta: Kananaskis, Forest Experimental Station Seebe , [51.100879, -115.087692], 15.vi.1968, ♀, CNCD 5014 GoogleMaps   , H.J. Teskey ( CNC). BANFF NATIONAL PARK   : Banff , [51.180275, -115.568433], 15.vii.1922, 3♂, CNCD 13621–13623 GoogleMaps   , C.B.D. Garrett ( CNC); ♀, JSS 19432 View Materials , N.B. Sanson ( CNC); 11.vii.1951, ♀, CNCD 13619, ( CNC)   . British Columbia: CATHEDRAL PROV. PARK   : Glacier Lake , [49.055785, -120.207299], 6.vii.1986, ♀, RBCM ENT 9882357 View Materials , R GoogleMaps   . A. Cannings ( RBCM); fen, Lk. of the Woods trail, [49.08, -120.18], 26.vii.1988, ♀, JSS 20186 View Materials , S.G. Cannings ( UBCZ). Squamish , Diamond Head Trail , [49.811126, -123.07434], 1219m, 11.viii.1953, ♀, CNCD 13610 GoogleMaps   , W. R. M. Mason ( CNC). Duffey L. Blowdown Cr., lake S. of Gott Peak , [50.40416667, - 122.3416667], 21.vii.1988, ♀, RBCM ENT 9918197 View Materials GoogleMaps   , C.S. Guppy ( RBCM). Cornwall Hills Lookout , [50.7, - 121.5], 2037m, 14.vi.1989, ♂, RBCM ENT 990626 View Materials , R   . A. Cannings & C.S. Guppy ( RBCM). KOOTENAY NATIONAL PARK   : Daer-Pitts Aspen Control 2, [50.776662, -115.936917], 17.vi.–2.vii.2000, 2♂, CNCD 30908, 30909 GoogleMaps   , ♀, CNCD 30903 GoogleMaps   , G. Gareau ( CNC); Floe Lake , [51.054, -116.137], 1981m, 9.viii.1955, ♀, CNCD 13611 GoogleMaps   , J. R. W. McGillis ( CNC). MOUNT REVELSTOKE NATIONAL PARK   : [51.035979, -118.142509], 1828m, 26.vii.1952, ♀, CNCD 13612 GoogleMaps   , G.P. Holland ( CNC); 15.viii.1952, ♀, CNCD 13613   , G.J. Spencer ( CNC); Mount Harry , [51.035979, -118.142509], 2073m, 8.viii.1952, ♀, CNCD 13614 GoogleMaps   , G.J. Spencer ( CNC); Mt. Revelstoke , [51.05, - 118.1333333], 1829m, 7.viii.1952, ♀, RBCM ENT 99188105 View Materials   , G.P. Holland ( RBCM); Eva Lake Trail , [51.079905, -118.108837], 1828m, 6.viii.1952, ♀, CNCD 13615 GoogleMaps   , G.J. Spencer ( CNC). SKENNA- QUEEN CHARLOTTE R   . D.: Tlell, Queen Charlotte Islands , [53.562591, -131.93235], 25.v.1957, ♂, CNCD 13620 GoogleMaps   , E.E. MacDougall ( CNC). NORTHERN ROCKIES R   . D.: Summit Lake, Mile 392 of Alaska Highway , [58.648201, -124.666912], 1372m, 1.vii.1959, ♀, CNCD 13603, R GoogleMaps   . E. Leech ( CNC); 1.vii.1959, ♀, CNCD 13605   , 2–4.vii.1959, 3♀, CNCD 13606– 13608   , 6.vii.1959, ♀, CNCD 13604   , E.E. MacDougall ( CNC). Ft. Nelson , [58.804594, -122.697436], 4.vii.1949, ♀, JSS 19993 View Materials , J.K. Morie ( UBCZ). Liard R GoogleMaps   . hotsprings, [59.425991, -126.096398], 23.vii.1987, 3♀, JSS 20176 View Materials – 20178, S.G. Cannings ( UBCZ). Fireside , [59.666676, -127.14242], 24.v.1980, CNCD 60083 GoogleMaps   , Bruce Gill ( CNC). 7 miles N Lions Bay , 18.v.1979, ♂, CNCD 5463   , G.F. Hevel ( CNC). Spanish Hills, Galiano Island , 10.v.1980, CNCD 60094   , G.G.E. Scudder ( CNC)   . Yukon Territory: Carcross Dunes at Bennett L. beach, [60.17066, -134.71809], 666m, 25.vi.2009, ♀, JSS 20819 View Materials , Lee Mennell ( RBCM). Takhini R GoogleMaps   ., west dunes 6.8km NNE of Kusawa L. outlet, [60.66824, -136.07664], 19.vi.2009, ♀, JSS 20820 View Materials , S. Cannings ( RBCM). Sheldon Lake , [62.616763, - 131.266603], 914m, 21.vii.1960, ♀, CNCD 13561 GoogleMaps   , J.E.H. Martin ( CNC). DEMPSTER HIGHWAY: North Klondike River, Km 64 [64.45056, -138.218356], 9.vi.1980, ♂, JSS 18376 View Materials , R GoogleMaps   . J. Cannings ( CNC)   . United States of America: Alaska: MATANUSKA- SUSITNA   CO.: Matanuska, [61.541945, -149.229674], 29.v.1944, ♀, JSS 19431 View Materials , J. Chamberlin ( CNC). Nome Area, Mile 17 of Kougarok Road , [64.70611111, -165.2972222], 26–28.vi.2005, ♀, CNCD 30899 GoogleMaps   , J.& R. Skevington ( CNC)   . Colorado: Pike's Peak Summit , [38.840342, -105.045006], 14.viii.1977, ♀, USNM ENT 258091 View Materials GoogleMaps   , A.B. Gurney ( USNM). GUNNISON CO.: Ragged Mountain , [39.118885, -107.407678], 20.vi.1950, ♂, CNCD 26345 GoogleMaps   , C.A. Downing ( CNC). CLEAR CREEK   CO.: Mount Evans , [39.645575, -105.594897] 22.vii.1961, ♀, CNCD 26335 GoogleMaps   , J.G. Chillcott ( CNC); 3.viii.1961, 2♀, CNCD 26330, 26331   , S.M. Clark ( CNC); 3.viii.1961, 2♀, CNCD 26332, 26333   , W. R. M. Mason ( CNC); 4.viii.1961, ♂, CNCD 26342   , J. R. Stainer ( CNC); 10.viii.1961, ♀, CNCD 26334   , C.H. Mann ( CNC); Timberline, Mount Evans , 3566m, 22.vii.1961, ♀, CNCD 26336   , C.H. Mann ( CNC); 22.vii.1961, ♀, CNCD 26337   , B.H. Poole ( CNC); Echo Lake, Mt. Evans , [39.658085, - 105.6035], 3231m, 22.vii.1961, ♀, CNCD 26338 GoogleMaps   , J.G. Chillcott ( CNC); Doolittle Ranch, Mt. Evans , [39.675739, - 105.601348], 2987m, 12.viii.1961, ♀, CNCD 26339 GoogleMaps   , J. R. Stainer ( CNC); Guanella Pass , [39.594992, - 105.711109], 3536m, 14.vii.1961, ♀, CNCD 26340 GoogleMaps   , S.M. Clark ( CNC). Brainard Lake Rec. Area 4mi W of Ward Colorado, [40.069261, -105.584835], 11.viii.1952, ♀, JSS 21103 View Materials , R. R GoogleMaps   . Dreisbach ( MSUC); 21.viii.1977, 2♂, USNM ENT 258062 View Materials , 258063 View Materials   , A.G. Lavallee ( USNM). Cameron Pass , [40.520816, -118.227668], 28.vii.1954, ♂, OSAC 133386 View Materials GoogleMaps   , Chas. L. Fluke ( OSAC). North Park , [40.73, -106.18], 1.vii.1932, ♀, JSS 20665 View Materials , ( CSUC)   . Washington: MT. RANIER NATIONAL PARK   : Paradise Valley, [46.782709, -121.727952], 15.vii.1920, ♂, JSS 23880 View Materials , 18.vii.1920, 7♂, JSS 23722 View Materials , 23888, 23889, 23893, 23894, 23900, 23904, 19.vii.1920, 2♂, JSS 23886 View Materials , 23887, ♀, JSS 23718 View Materials , 25.vii.1920, ♂, JSS 23883 View Materials , E.C. Van Dyke ( CAS); 18.vii.1920, ♂, JSS 20613 View Materials , E.C. Van Dyke ( EMEC); Carbon River near Ranger station , [46.85, -121.75], 15.viii.1999, ♀, JSS 20681 View Materials , B. Kondratieff ( CSUC); Louis Lake , Fryingpan Cr. , Sunrise Rd. , [46.85, -121.75], 17.vi.2004, ♂, JSS 20804 View Materials , B. Kondratieff, J. Schmidt, J. Owens ( CSUC). Seattle, [47.60621, -122.332071], 16.vi.1901, ♀, OSAC 133444 View Materials , ( OSAC). MT. BAKER- SNOQUALMIE NATIONAL FOREST GoogleMaps   : Mt. Baker, Picture Lake, [48.866217, -121.676533], 1273m, 7.vii.2010, ♂, JSS 23706 View Materials , ♀, JSS 24625 View Materials , A. Young ( DEBU); Silver Fir Campground , [48.90495, 121.697917], 613m, 8.vii.2010, ♂, JSS 23708 View Materials , 9.vii.2010, ♀, CNCD 35311, 60043 GoogleMaps   , M.M. Locke ( CNC); 9.vii.2010, CNCD 60046, CNCD 60047   , A. Young ( CNC)   . Wyoming: Wyoming , [43.084281, -107.556417], 1952, ♀, CNCD 26329 GoogleMaps   , F.M. Hull ( CNC). Yellowstone National Park , [44.587719, -110.537673], 20.vii.1925, ♂, CNCD 26343 GoogleMaps   , A.A. Nichol ( CNC)   .

CNC

Canadian National Collection of Insects, Arachnids, and Nematodes

RBCM

Royal British Columbia Museum

R

Departamento de Geologia, Universidad de Chile

UBCZ

University of British Columbia, Spencer Museum

USNM

Smithsonian Institution, National Museum of Natural History

OSAC

Oregon State Arthropod Collection

CSUC

California State University, Chico, Vertebrate Museum

MT

Mus. Tinro, Vladyvostok

CAS

California Academy of Sciences

EMEC

Essig Museum of Entomology

DEBU

Ontario Insect Collection, University of Guelph

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Diptera

Family

Syrphidae

Genus

Dasysyrphus