Dasysyrphus Enderlein 1938

Locke, Michelle M. & Skevington, Jeffrey H., 2013, Revision of Nearctic <i> Dasysyrphus </ i> Enderlein (Diptera: Syrphidae), Zootaxa 3660 (1), pp. 1-80 : 28-29

publication ID	https://doi.org/ 10.11646/zootaxa.3660.1.1
publication LSID	lsid:zoobank.org:pub:95ADD39C-98BE-4879-B070-34A5D86BD67B
persistent identifier	https://treatment.plazi.org/id/03893F32-FFA8-FFBD-FF46-FF70FE8A8830
treatment provided by	Felipe
scientific name	Dasysyrphus Enderlein 1938
status

Treatment

Dasysyrphus Enderlein 1938 View in CoL View at ENA

Figures: 1 (field photos), 5–19 (lab photos), 20–22 (range maps)

Synonyms and References:

Conosyrphus Matsumura 1918: 11 (name preoccupied by Conosyrphus Frey 1915 ). Type species Conosyrphus okunii Matsumura 1918 View in CoL

Dasysyrphus Enderlein 1938: 208 View in CoL . Type species Scaeva albostriata Fallén 1817 View in CoL

Syrphella Goffe 1944: 129 . Type species Scaeva tricincta Fallén 1817 View in CoL

Dendrosyrphus Dusek & Laska 1967: 365 . Type species Syrphus lunulatus Meigen 1822 View in CoL

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 View FIGURE 7 , 9 View FIGURE 9 & 17 View FIGURE 17 ), in others they do not ( Figs 5 View FIGURE 5 , 6 View FIGURE 6 , 8 View FIGURE 8 , 10–16 View FIGURE 10 View FIGURE 11 View FIGURE 12 View FIGURE 13 View FIGURE 14 View FIGURE 15 View FIGURE 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 View FIGURE 6 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 View FIGURE 13 View FIGURE 14 View FIGURE 15 View FIGURE 16 View FIGURE 17 & 19 View FIGURE 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. albostriatus and D. eggeri it tapers to a point ( Fig. 19 View FIGURE 19 ), it is mostly sclerotized but membranous at apex of the horn, with either setae, pile or bare dorsally ( Figs 6–17 View FIGURE 6 View FIGURE 7 View FIGURE 8 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 View FIGURE 13 View FIGURE 14 View FIGURE 15 View FIGURE 16 View FIGURE 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 View FIGURE 20 View FIGURE 21 ).

Key to Species of Nearctic Dasysyrphus Enderlein 1938 View in CoL

1. Tergites 3 & 4 with maculae that extend over the abdominal margin, usually reaching the edge of the abdomen (cf. Fig. 7D View FIGURE 7 ).. .................................................................................................. 11.

1'. Tergites 3 & 4 with maculae that do not reach the abdominal margin (cf Fig. 8D View FIGURE 8 ).................................. 2.

2. Gena dark in colour (dark brown to black) (cf Fig. 8D View FIGURE 8 )....................................................... 5.

2'. Gena light in colour (yellow to light brown), sometimes with a black vitta between face and gena (cf Fig. 16C View FIGURE 16 ).......... 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) View in CoL Western (southern AB & BC, south to CA & NM; Fig. 20A View FIGURE 20 ); 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 View FIGURE 16 )................................................ 4.

4. Gena separated from face by black vitta; wing cells br and bm almost entirely bare ( Figs 16A–C View FIGURE 16 )............................................................................................ richardi Locke & Skevington sp. nov. Southwestern (NM; Fig. 20C View FIGURE 20 ); 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 View FIGURE 10 ).......................................................................................... lotus (Williston) Southwestern (CA & AZ, south to Mexico; Fig. 21A View FIGURE 21 ); Williston 1887: 75.

5. Sternite 2 with dark oval macula ( Figs 15A–D View FIGURE 15 , 18C View FIGURE 18 )............................................ pinastri (DeGeer) Greenland ( Fig. 21D View FIGURE 21 ); De Geer 1776: 113, Pl. 7, Figs 1–7. View FIGURE 1 View FIGURE 2 View FIGURE 3

5'. Sternite 2 with dark fascia ( Fig. 18D View FIGURE 18 )..................................................................... 6.

6. Tergites 3 & 4 with maculae not greatly constricted, more or less uniform in thickness (cf Fig. 13A View FIGURE 13 )................... 8.

6'. Tergites 3 & 4 with maculae greatly constricted medially, sometimes completely divided ( Figs 5A View FIGURE 5 , 12A & B View FIGURE 12 )........... 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 View FIGURE 12 )........... occidualis Locke & Skevington sp. nov. Western (AK, south to CO; Fig. 21B View FIGURE 21 ); 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 View FIGURE 5 ).......................................................... amalopis (Osten Sacken) Northern (YK, east to northern NL; NH; Fig. 20A View FIGURE 20 ); 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 View FIGURE 8 )....................... laticaudus (Curran) Eastern and boreal (AK, east to NL, south to NH, Fig. 20C View FIGURE 20 ); 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 View FIGURE 13 ); profemur dark basally, light apically to entirely dark (cf Fig. 14B View FIGURE 14 )............................ 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 View FIGURE 11 , 18B View FIGURE 18 )................................................................ nigricornis (Verrall) Northern (AK, east to northern NL; Greenland; Fig. 21A View FIGURE 21 ); 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 View FIGURE 14 ) or is shaped differently ( Fig. 13D View FIGURE 13 ).................................................................. 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 View FIGURE 13 )...................................................... pacificus (Lovett) Western, (southern BC, south to CA; Sierra Nevada, Cascades and Costal Mountain Ranges; Fig. 21C View FIGURE 21 ); 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 View FIGURE 14 )............................................... pauxillus (Williston) Western (AK, south to NM; Rocky Mountain Range; Fig. 21D View FIGURE 21 ); 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 View FIGURE 9 )................................. limatus (Hine) Widespread (AK, east to NS, south to CO and MA; Fig. 20D View FIGURE 20 ); 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 View FIGURE 7 & 17A View FIGURE 17 )........................ 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 View FIGURE 7 )............................................................................................. intrudens complex (Osten Sacken) Widespread (AK, east to NL, south to CA, NM and TN; Fig. 20B View FIGURE 20 ); 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 View FIGURE 17 )............................................................. venustus (Meigen) Widespread (AK, east to NS, south to NM & NC; Fig. 22); Meigen 1822: 299.

Taxonomy