Identifying Syrphus Hover Flies of North America
Work in progress
- Before trying to identify a Syrphus to species, make sure it is not a similar genus such as Eupeodes, Epistrophe, Parasyrphus, Megasyrphus, Meliscaeva, etc. (easier said than done)
- Currently only suitable for identifying northeastern species.
S. torvus
- Hairy eyes, black frons
Hind femur 3/4 black from base
https://bugguide.net/node/view/1371184/bgimage
https://bugguide.net/node/view/1449626/bgimage
https://bugguide.net/node/view/910105/bgimage
https://bugguide.net/node/view/1791203/bgimage
https://bugguide.net/node/view/1201263/bgimage
S. ribesii
- Frons black
- Female femora all yellow
Male hind femur 3/4 black from base
https://bugguide.net/node/view/1302736/bgimage
https://bugguide.net/node/view/1060367/bgimage
https://bugguide.net/node/view/982474/bgimage
https://bugguide.net/node/view/1021446
https://www.inaturalist.org/observations/32790751
S. knabi
- Yellow bands meet abdomen margin broadly, bands mostly straight
- Female hind femur yellow except black band near end, metabasitarsus (base of hind foot) is orange/yellow rather than dark
-
M "hind femur yellowwith apical half mostly brownish"
https://bugguide.net/node/view/1542944/bgimage
https://bugguide.net/node/view/1405860/bgimage
https://bugguide.net/node/view/31751/bgimage
https://www.inaturalist.org/observations/17376379
https://bugguide.net/node/view/1109151/bgimage
https://bugguide.net/node/view/1493264/bgimage, https://bugguide.net/node/view/1328499/bgimage
Female S. knabi, from https://www.inaturalist.org/observations/17376379
S. rectus
- Yellow bands narrow toward abdomen margin
- Female hind femur yellow, usually dark ring between the middle and the end; metabasitarsus (base of hind foot) is dark
-
Male hind femur 2/3 to 3/4 black from base
https://www.inaturalist.org/observations/7413694
https://bugguide.net/node/view/912947/bgimage
https://bugguide.net/node/view/474223/bgimage
Female S. rectus, from https://www.inaturalist.org/observations/7413694
S. vitripennis
- Yellow bands meet abdomen margin narrowly
- Female hind femur 1/3 or 3/4 black from base
Male not separable from S. rectus
https://bugguide.net/node/view/876186/bgpage
https://bugguide.net/node/view/1655754/bgimage
https://bugguide.net/node/view/1596113/bgimage
https://bugguide.net/node/view/1505795/bgimage
https://www.inaturalist.org/observations/33738216
S. opinator
- Black abdomen margin (except on T2, which separates from Eupeodes)
- Only western North America
Not separable from S. intricatus if both are valid species?
https://bugguide.net/node/view/1614867/bgimage
https://bugguide.net/node/view/169722/bgimage
https://bugguide.net/node/view/1029234/bgimage
https://bugguide.net/node/view/792916
Lots of sad unresolved conversations: https://bugguide.net/node/view/241862/bgimage
https://bugguide.net/node/view/268287/bgimage
https://bugguide.net/node/view/264398
S. sexmaculatus
- Has six spots on abdomen instead of 2 bands and 2 spots (the normal 2 yellow bands are split up)
- Northern forest/tundra and western subalpine habitat
- Photo?
S. attenuatus
- Has six spots on abdomen instead of 2 bands and 2 spots
- Yellow abdomen margin
- Canada and northern US
- "hind femur entirely yellow or with up to basal half black"
- Photo?
S. currani
- M "Tergites 3 and 4 with yellow bands emarginate posteriorly, notreaching lateral margins or reaching them only very narrowly." / F "Tergites 3 and 4 with yellow bands reaching lateral marginsvery narrowly to broadly."
- "Femora yellow"
- Western US (Oregon to Colorado)
S. sonorensis?
- "Yellow bands of tergites 3 and 4 entire, not extending to lateralmargins or reaching them very narrowly or over about half their length."
- "hind femur black with apex narrowly yellow" (like torvus and vitripennis)
- Arizona, New Mexico
S. dimidiatus
S. doesburgi
S. monoculus
Sources
- BugGuide
- Field Guide to the Flower Flies of Northeastern North America
- https://cjai.biologicalsurvey.ca/mylmst_23/mylmst_23_537.HTM
- Vockeroth 1992 http://esc-sec.ca/wp/wp-content/uploads/2017/03/AAFC_insects_and_arachnids_part_18.pdf#page=364
- BOLD images http://beta.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxon=syrphus&searchTax=