Conosyrphus Matsumura 1918: 11 Conosyrphus Frey 1915 Conosyrphus okunii Matsumura 1918 Dasysyrphus Enderlein 1938: 208 Scaeva albostriata Fallén 1817 Syrphella Goffe 1944: 129 Scaeva tricincta Fallén 1817 Dendrosyrphus Dusek & Laska 1967: 365 Syrphus lunulatus Meigen 1822 Revision of Nearctic <i> Dasysyrphus </ i> Enderlein (Diptera: Syrphidae) Locke, Michelle M. Skevington, Jeffrey H. Zootaxa 2013 2013-05-22 3660 1 1 80 425H 414800 Enderlein 1938 Enderlein 1938 [151,502,151,177] Insecta Syrphidae Dasysyrphus Animalia Diptera 27 28 Arthropoda genus  Synonyms and References:      Conosyrphus Matsumura 1918: 11(name preoccupied by  Conosyrphus Frey 1915). Typespecies  Conosyrphus okunii Matsumura 1918     Dasysyrphus Enderlein 1938: 208. Typespecies  Scaeva albostriata Fallén 1817     Syrphella Goffe 1944: 129. Typespecies  Scaeva tricincta Fallén 1817     Dendrosyrphus Dusek & Laska 1967: 365. Typespecies  Syrphus lunulatus Meigen 1822  Diagnosis: Eye pilose; metasternum bare; at least at apical ⅓ of wing densely microtrichose; abdomen oval with abdominal margin present, dark with light maculae present on tergites 2, 3 & 4. Description: Body Length: 5.0– 11.7mm; Wing Length: 4.5–11.4mm Head: Frons dark with light pollenose fascia (in males it runs along ventral edge of where eyes meet, in females it is variable and can be diagnostic); face light, typically with dark vitta ¼–½ the width of the face, reaching antennal socket or not; face with medial tubercle, more prominent in some species than others; gena dark or light; occiput dark, covered in light pollen, pile typically light; eyes covered in dense pile, male holoptic, female dichoptic; scape, pedicel and flagellomere light to dark, arista bare. Thorax: Scutum dark, usually with shiny or metallic sheen (lighting can enhance sheen); scutellum variable in colour (light to dark); wings densely microtrichose on apical ⅓, location and extent of bare areas on basal ⅔ varies between species; posterior anepisternum, katepisternum, anepimeron, katepimeron with dense pile, usually light, sometimes dark or mixture (colour variable within species); anterior anepisternum, meron, metasternum bare; pterostigma elongate and dark (brown); haltere light, sometimes knob or capitulum darkened; calypter light with long light pile around edge and very short light pile on both dorsal and ventral surfaces; legs cylindrical, femora typically basally dark, apically light, tibiae light, metatibia sometimes with dark band close to apex, tarsi light usually with darker anterior side. Abdomen: Oval; tergites dark with light maculae, maculae on tergite 2 typically oval, while maculae on tergites 3&4 are typically longer, arcuate, lunulate, transverse or oblique, sometimes meeting medially, maculae of some species cross abdominal margin ( Figs 7, 9& 17), in others they do not ( Figs 5, 6, 8, 10–16); sternites light with dark maculae or fasciae, sometimes fascia absent on sternite 2; terminalia dark. Male Genitalia: Hypandrium roughly trapezoid in shape, smooth, without pile; epandrium rounded ventrally with posterior projection (see Figs 6–17& 19), smooth, without pile; surstylus more or less triangular in shape in lateral view, flattened posteriorly or anteroposteriorly, long pile on dorsal, laterodorsal and posterodorsal sides, row of spines on posteromedial edge; cercus oval with long pile over entire surface; gonostylus variably shaped; basiphallus variable in shape, but roughly shaped like a faucet, posterodorsal edge bare or covered in pile or spines; distiphallus elongate, basal end flared out into a horn in most species, in  D. albostriatusand  D. eggeriit tapers to a point ( Fig. 19), it is mostly sclerotized but membranous at apex of the horn, with either setae, pile or bare dorsally ( Figs 6–17). Etymology: From the Greek, dasys, meaning thick with hair, hairy, shaggy; and syrphos(masculine), meaning a kind of fly. Distribution: Throughout Nearctic and Palaearctic (excluding North Africa). Throughout the Neotropical and Oriental regions, however there is low diversity in these regions. Not recorded from the Afrotropical or Australasian regions ( Figs 20–22).   Key to Species of Nearctic  Dasysyrphus Enderlein 1938    1. Tergites 3 & 4 with maculae that extend over the abdominal margin, usually reaching the edge of the abdomen (cf. Fig. 7D).. .................................................................................................. 11.  1'. Tergites 3 & 4 with maculae that do not reach the abdominal margin (cf Fig. 8D).................................. 2.   2. Gena dark in colour (dark brown to black) (cf Fig. 8D)....................................................... 5.  2'. Gena light in colour (yellow to light brown), sometimes with a black vitta between face and gena (cf Fig. 16C).......... 3.   3. Tergites 3 & 4 with maculae arcuate, medial edge flattened, usually broadly contacting the anterior edge of the tergite (Figs 6A–D)...................................................................................   creper(Snow)Western (southern AB & BC, south to CA & NM; Fig. 20A); Snow 1895: 234.  3'. Tergites 3 & 4 with maculae oblique, more straight, with medial edge rounded and usually meeting medially, sometimes contacting anterior edge of tergite, but not as broadly (cf Fig. 16A)................................................ 4. 4. Gena separated from face by black vitta; wing cells br and bm almost entirely bare ( Figs 16A–C)............................................................................................   richardiLocke & Skevington sp. nov.Southwestern (NM; Fig. 20C); Locke & Skevington, here described. 4'. Gena and face continuously yellow, not separated by black vitta; wing cells br and bm partly microtrichose ( Figs 10A–D)..........................................................................................   lotus(Williston)Southwestern (CA & AZ, south to Mexico; Fig. 21A); Williston 1887: 75. 5. Sternite 2 with dark oval macula ( Figs 15A–D, 18C)............................................   pinastri(DeGeer) Greenland( Fig. 21D); De Geer 1776: 113, Pl. 7, Figs 1–7. 5'. Sternite 2 with dark fascia ( Fig. 18D)..................................................................... 6. 6. Tergites 3 & 4 with maculae not greatly constricted, more or less uniform in thickness (cf Fig. 13A)................... 8. 6'. Tergites 3 & 4 with maculae greatly constricted medially, sometimes completely divided ( Figs 5A, 12A & B)........... 7. 7. Male surstylus with a prominent posterolateral edge. Cell br usually with bare areas above base of spurious vein (sometimes very small); tergites 3 & 4 with maculae usually divided ( Figs 12A–E)...........   occidualisLocke & Skevington sp. nov.Western (AK, south to CO; Fig. 21B); Locke & Skevington, here described. 7'. Male surstylus without a prominent posterolateral edge. Cell br densely microtrichose; tergites 3 & 4 with maculae either divided or not ( Figs 5A–D)..........................................................   amalopis(Osten Sacken)Northern (YK, east to northern NL; NH; Fig. 20A); Osten Sacken 1875: 148. 8. Tergite 2 with anterolateral corner of maculae extending anterolaterally into a point, in females reaching the edge of the abdomen; profemur light, usually entirely so but some dark basally ( Figs 8A–E).......................   laticaudus(Curran)Eastern and boreal (AK, east to NL, south to NH, Fig. 20C); Curran 1925: 175, Pl. XI, Fig. 151. 8'. Tergite 2 with anterolateral corner of maculae not extending anterolaterally into a point, lateral edges of maculae usually rounded (cf Fig. 13B); profemur dark basally, light apically to entirely dark (cf Fig. 14B)............................ 9. 9. Size 5.5–7.7 mm, dark flies; profemur ½–entirely dark; pubescent band on female frons complete but sometimes not well defined; males with tergite 2 maculae typically reduced and positioned toward the lateral edge; tergites 3 & 4 uniform in width and slightly constricted medially; gonostylus boot-shaped with projection on posterodorsal surface that projects posterodorsally ( Figs 11A–E, 18B)................................................................   nigricornis(Verrall)Northern (AK, east to northern NL; Greenland; Fig. 21A); Verrall 1873: 251. 9'. Combination of characters not as above. Size 5.0– 9.7 mm, profemur never entirely dark (¼–⅔ dark basially); pubescent band on female frons interrupted; males with tergite 2 maculae large (¼–½ width of tergite); tergites 3 & 4 uniform in width and slightly constricted medially; gonostylus boot-shaped with projection on posterodorsal surface that projects more dorsally ( Fig. 14D) or is shaped differently ( Fig. 13D).................................................................. 10. 10. Male gonostylus with narrow, wavy projection on posterodorsal surface. Wing typically largely bare basally, with cells br and bm with large bare areas ( Figs 13A–D)......................................................   pacificus(Lovett)Western, (southern BC, south to CA; Sierra Nevada, Cascadesand Costal Mountain Ranges; Fig. 21C); Lovett (in Cole & Lovett) 1919: 245. 10'. Male gonostylus with projection on posterodorsal surface straight; wing typically densely microtrichose, sometimes with bare areas in cells r 1, br, bm and/or c ( Figs 14A–D)...............................................   pauxillus(Williston)Western (AK, south to NM; Rocky Mountain Range; Fig. 21D); Williston 1887: 74. 11. Tergite 2 with maculae very small, <¼ width of tergite; tergites 3 & 4 with maculae transverse, usually narrow, with slight swelling on medial edge and narrowing towards margin ( Figs 9A–D).................................   limatus(Hine)Widespread(AK, east to NS, south to CO and MA; Fig. 20D); Hine 1922: 146. 11'. Tergite 2 with maculae large,> ¼ width of tergite; tergites 3 & 4 with maculae distinctly arcuate, lunulate or oblique, with at least slight swelling on medial edge, sometimes constricted medially ( Figs 7A, C, E& 17A)........................ 12. 12. Tergites 3 & 4 with maculae distinctly arcuate or lunulate, with anterior edge forming a distinct U or V shape, maculae are distinctly constricted, sometimes dividing in half with a large swelling on the medial edge ( Figs 7A–F).............................................................................................   intrudenscomplex (Osten Sacken)Widespread (AK, east to NL, south to CA, NM and TN; Fig. 20B); Osten Sacken 1877: 326. 12'. Tergites 3 & 4 with maculae are more oblique, no distinctive constriction in the centre, never divided and not greatly swollen on medial edge ( Figs 17A–D).............................................................   venustus(Meigen)Widespread(AK, east to NS, south to NM & NC; Fig. 22); Meigen 1822: 299.  Taxonomy