Dasysyrphus amalopis (Osten Sacken)

Locke, Michelle M. & Skevington, Jeffrey H., 2013, Revision of Nearctic <i> Dasysyrphus </ i> Enderlein (Diptera: Syrphidae), Zootaxa 3660 (1), pp. 1-80: 29-32

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Dasysyrphus amalopis (Osten Sacken)


Dasysyrphus amalopis (Osten Sacken)  

Figures: 5A–D, 20A

Synonyms and References:

Syrphus amalopis Osten Sacken 1875: 148   (original description)

Curran 1925: 179 (discussion, amalopis   s.l.)

Metasyrphus amalopis (Osten Sacken)   :

Fluke 1933: 110 (in part; key, redescription and transfer to Metasyrphus   )

Dasysyrphus amalopis (Osten Sacken)   :

Stone et al. 1965 (in part): 563 (catalogue and transfer to Dasysyrphus   )

Vockeroth 1986: 202 (lectotype designation and discussion)

Vockeroth 1992: 63 (in part; redescription)

Diagnosis: Abdominal maculae do not meet abdominal margin; maculae on tergites 3&4 are constricted medially and usually not divided ( Figs 5A & B View FIGURE 5 ). Wing cells are densely microtrichose ( Fig. 5D View FIGURE 5 ). Surstylus without a prominent posterolateral edge ( Fig. 5C View FIGURE 5 ). Similar to D. occidualis   , but D. occidualis   has maculae on tergites 3&4 either divided or undivided ( Figs 12A & B View FIGURE 12 ), cell br usually with a small bare area above base of spurious vein and a prominent posterolateral edge on the surstylus ( Fig. 12D View FIGURE 12 ).


Body Length: 7.8–10mm; Wing Length: 7.7–8.7mm

Head: Frons dark with light pollenose fascia (in males it runs along ventral edge of where eyes meet, in females it is continuous, ¼–½ the length between the antennae and ocelli) and dark pile; face light with dark vitta ¼–⅓ the width of the face sometimes reaching antennal socket, face with dark pile; gena dark with pile light to dark; occiput dark, covered in light pollen, pile light; scape, pedicel and flagellomere dark.

Thorax: Scutum dark, may appear shiny or metallic, pile varying from all dark to mixed to all light, more light anteriorly and posteriorly; scutellum light (dark yellow) to dark with darker lateral edges, light pile along anterior edge and dark pile elsewhere; wing completely densely microtrichose ( Fig. 5D View FIGURE 5 ); haltere light; femora ⅔–¾ dark basially, ¼–⅓ light apically, tibiae dark with very basal end light, tarsii dark.

Abdomen: Maculae on tergite 2 large and oval, usually with slight narrowing medially, ⅓–<½ the width of tergite 2, maculae on tergites 3 & 4 are oblique, constricted medially and usually not divided, posterior edge of maculae straight, maculae do not reach abdominal margin ( Fig. 5B View FIGURE 5 ); sternite 2 light with a dark triangular macula, usually not connecting with the lateral edges of the sternite, sternites 3 & 4 are light with dark fasciae.

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 claw-shaped, pile on dorsal surface; basiphallus elongate, basally bent at about a 90 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 slightly enlarged ventrally at bend ( Fig. 5C View FIGURE 5 ).

Intraspecific variation: From the specimens we have had the chance to observe the maculae on tergites 3 & 4 are usually not divided ( Fig. 5A View FIGURE 5 ). Sometimes only the maculae on tergite 3 are divided and sometimes they are divided on both tergites 3 & 4. The lectotype male has entire maculae, whereas the paralectotype female has divided maculae.

Etymology: From the Greek, amalos meaning soft, tender, weak and – opis, meaning having the appearance of, like.

Distribution: Northern Canada (MB, NL, QC, YK) and Northeastern USA (NH) ( Fig. 20A View FIGURE 20 )

Ecology: Collected from June–July at elevations from sea level– 1006m.

Discussion: In addition to the two specimens selected as lectotype and paralectotype by Vockeroth (1986), Osten Sacken (1875) discussed a third specimen and included it in his description of the species. This third specimen has abdominal maculae that cross the abdominal margin. This third specimen is not a specimen of D. amalopis   but a specimen of the D. intrudens   complex, and has caused much confusion over the name D. amalopis   . Vockeroth (1986) pointed out that Fluke (1933) discussed many specimens of D. amalopis   with maculae reaching the margin. Vockeroth stated that he believed those specimens belonged to his concept of D. venustus   . We argue that specimens described as D. amalopis   that have maculae that cross the abdominal margin belong to the D. intrudens   complex. Fluke (1933) does have D. amalopis   key out in two places in his key. The D. amalopis   keyed out in couplet 54 pertains to D. amalopis   s.s. and D. occidualis   , while the D. amalopis   keyed out in couplet 56 pertains to the D. intrudens   complex.

The lectotype and paralectotype are the only known specimens of this species from eastern North America south of northern Quebec and Labrador. Our new species, Dasysyrphus occidualis   , has been confused with D. amalopis   . However, the COI sequences and male genitalia characters provide evidence for these being two distinct species with an identical habitus. Dasysyrphus amalopis   ranges from southern Yukon to northern Labrador ( Fig. 20A View FIGURE 20 ), while D. occidualis   ranges from Alaska, south to Colorado ( Fig. 21B View FIGURE 21 ). Specimens referred to as D. amalopis   from western Canada or the US are most likely that of D. occidualis   and in the overlap zone in southern Yukon male genitalia and/or COI sequences should be used to confidently identify specimens. Despite the long standing use of the name D. amalopis   , the similar new species, D. occidualis   , has been much more frequently collected.

It is not known why no other specimens are known from as far south as the lectotype and paralectotype. They were both collected in the White Mountains, in New Hampshire. The date of their collection is unknown, however their description by Osten Sacken was published in 1875, so they would have been collected previous to that. It is possible that they are rare and have thus not been collected again or that their habitat or climatic conditions have changed resulting in their extirpation. More collecting should be done in the Appalachians at high elevation to see if this species still exists that far south.

Type Material: “White Mts./ Austin”, “Osten/ Sacken/ Coll.”, red label “Type/ 4092”, “ Syrphus   / amalopis/ Type Species O.S.”, yellow label “ LECTOTYPE / Syrphus   / amalopsis O.S./ Desig. Thompson 1971”, “ Jan.–July 2003 / MCZ Image/ Database”, J. Skevington/ Specimen #/ 23785”, ♂, deposited in the Museum of Comparative Zoology, Harvard University (MCZ). Missing head. (examined)

Material Examined:

Paralectotype: United States of America: New Hampshire: Gorham , [44.387788, -71.17313], ♀, JSS 23786 View Materials ( MCZ) GoogleMaps   . Other Material Examined: Canada: Manitoba: CHURCHILL GoogleMaps   REGION: Weir , [58.4026, -94.129], ♂, 25.vii.2007, ♀, 07 PROBE 4723 GoogleMaps   , L.E. Roscoe ( CNC); Burn site North of Twin lakes, [58.61861111, -93.82888889], 5.vii.2007, ♂, CNCD 9607 GoogleMaps   , J. Skevington ( CNC); Twin Lakes , [58.63, -93.819], 14m, 19.vii.2009, ♀, 09 PROBE 176, ( CNC), 26.vi.2010 – 2.vii.2010, ♂, 10 PROBE 13673   , 5.vii.2010 – 9.vii.2010, ♀, 10 PROBE 13805   , J. Wang ( USNM); Goose Creek , [58.649, -94.193 W], 19.vii.2009, ♀, 09 PROBE 25 GoogleMaps   , A. Thielman ( CNC); Farnworth Lake ( Landing L), [58.7045, -94.0525], 14m, 14.vii.2010, ♀, 10 PROBE 14269 GoogleMaps   , 14.vii.2010 – 19.vii.2010, ♂, 10 PROBE 15042   , 28.vi.2010, ♂, 10 PROBE 10909   , 28.vi.2010 – 6.vii.2010, ♀, 10 PROBE 15283   , J. Wang ( CNC)   . Newfoundland and Labrador: Nain, Anatalak Bay , [56.5429, -61.689989], 16.vii.1928, ♂, JSS 19248 View Materials , A.C. Weed ( FMNH) GoogleMaps   . Quebec: Indian House Lake , [56.328482, -64.720845], 19.vii.1954; ♀, CNCD 13616 GoogleMaps   , 25.vii.1954, ♀, CNCD 13618 GoogleMaps   ,W. R. Richards ( CNC); 22.vii.1954, ♀, CNCD 13617, R   . Coyles ( CNC)   . Yukon Territory: La Force Lake , [62.683333, -132.333333], 1006m, 26.vi.1960, ♂, CNCD 13587 GoogleMaps   , J.E.H. Martin ( CNC)   .


Museum of Comparative Zoology


Canadian National Collection of Insects, Arachnids, and Nematodes


Smithsonian Institution, National Museum of Natural History


Field Museum of Natural History


Departamento de Geologia, Universidad de Chile














Dasysyrphus amalopis (Osten Sacken)

Locke, Michelle M. & Skevington, Jeffrey H. 2013

Syrphus amalopis

Osten Sacken, C. R. 1875: 148