Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

Order Diptera - Flies

Fly from Sawmill Creek - Scathophaga Dilophus orbatus - female large crane fly - Holorusia hespera crane fly? - Trichocera Crane Fly - Tipula caloptera some kind of beefly  - Systoechus Downeast Asilid horsefly - Hybomitra lasiophthalma - female
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Diptera (Flies)
Other Common Names
The common names of the members of this order (Diptera) are written as two words: crane fly, robber fly, bee fly, moth fly, fruit fly, etc. The common names of non-dipteran insects that have "fly" in their name are written as one word: butterfly, stonefly, dragonfly, scorpionfly, sawfly, caddisfly, whitefly, etc.
Synonyms and other taxonomic changes
Classification outlined in(1) probably should be adopted in the guide
Explanation of Names
Diptera Linnaeus 1758
Greek 'two-winged' (the name dates back to Aristotle, who noted the difference from typical four-winged insects(2)). The English fly originally signified any flying insect
~17,000 spp. in 2,222 genera of ~110 families in our area, the number of described species steadily growing(3); >150,000 described extant species in ~160 families worldwide(1)(4)(5)
DRAFT: Families represented in our area
Classification adapted from(5). Non-monophyletic groups in quotation marks; taxa not yet in the guide marked (*). BG family wish list and how to find members of the missing families here.
This is but a raw draft. The layout fails to reflect the multilayer hierarchy, but I'll figure out a way to do it without excessive font colors and sizes. =v=
Infraorder Bibionomorpha
0.5–40 mm
Adult flies, except for wingless species, have two functional wings and two halteres. The halteres are club-like appendages that are essentially the modified hind wings. The only other adult insects that only have two wings in both sexes are the Strepsiptera, which have the front wings reduced rather than the hind wings. Males of some species of Mayflies and scale insects have only front wings. A few tiny parasitic wasps, e.g. Mymarommatidae, have their hind wings reduced, but these can be distinguished from flies as the wasps have only one vein in their front wings and flies always have two or more veins in their wings as long as their wings are membranous.
The best general treatment of our fauna down to genus level in Manual of Nearctic Diptera Volume 1 & 2(6)(7)
For anatomy and terminology see(8)
Keys to larvae (UK fauna) in(9)
Keys to families of aquatic larvae(10)(11)(12)(13)(14)
Life Cycle
Larval morphology (brief outlook; McAlister 2014)
Higher classification of Diptera is in flux. Several teams worldwide are working to resolve the problems, which leads to breakthroughs, new questions, and much controversy. The classification adopted here uses several paraphyletic groups not used as formal groups in modern classfications(15), but are convenient for sorting out similar groups of flies. The latest summary of higher taxonomy and phylogeny of the order is provided in(5), although major changes may well expected.
Nematocera - A paraphyletic grouping of the most primitive flies. They have more antennal segments than the Brachycera.
Brachycera - A group with a reduced number of antennal segments.
Orthorrhapha - A subdivision of the Brachycera, includes most flies that don't have the circular pupal aperture of the Cyclorrhapha.
Cyclorrhapha - A subdivision of the Brachycera. These flies have the shared trait of a circular aperture where the adult flies emerge from the pupal case.
Aschiza - A paraphyletic subdivision of the Cyclorrhapha; includes flies lacking the ptinal suture characterizing the Schizophora.
Schizophora - A subdivision of the Cyclorrhapha: flies with a suture on the front of the head where a balloon-like structure, the ptilinum, is inflated to open up the puparium when the adult emerges.
Calyptratae - A subdivision of the Schizophora; they have several shared characteristics including the prominent lower calypter on the wing.
Acalyptratae - A paraphyletic subdivision that includes all Schizophora other than Calyptratae.
Print References
Internet References
Works Cited
1.Order Diptera Linnaeus, 1758. In: Zhang Z.-Q. (ed.) Animal biodiversity: An outline of higher-level classification...
Pape T., Blagoderov V., Mostovski M.B. 2011. Zootaxa 3148: 222–229.
2.Insects: Their Natural History And Diversity: With a Photographic Guide to Insects of Eastern North America
Stephen A. Marshall. 2006. Firefly Books Ltd.
3.American Insects: A Handbook of the Insects of America North of Mexico
Ross H. Arnett. 2000. CRC Press.
4.Thompson F.C., Pape T., Evenhuis N.L. (2013) Systema Dipterorum, Version 1.5
5.Episodic radiations in the fly tree of life
Wiegmann B.M. et al. 2011. Proc. Natl. Acad. Sci. USA 108(14): 5690-5695.
6.Manual of Nearctic Diptera Volume 1
Varies for each chapter; edited by J.F. McAlpine, B.V. Petersen, G.E. Shewell, H.J. Teskey, J.R. Vockeroth, D.M. Wood. 1981. Research Branch Agriculture Canada.
7.Manual of Nearctic Diptera Volume 2
Varies for each chapter; edited by J.F. McAlpine, B.V. Petersen, G.E. Shewell, H.J. Teskey, J.R. Vockeroth, D.M. Wood. 1987. Research Branch Agriculture Canada.
8.Anatomical Atlas of Flies
9.An introduction to the immature stages of British flies
Smith K.G.V. 1989. RES Handbooks for the Identification of British Insects 10(14); 280 pp.
10.Guide to Aquatic Invertebrates of the Upper Midwest
University of Minnesota. 2004. University of Minnesota.
11.Digital key to aquatic insects of North Dakota
12.Bright E. (2002-2011) Aquatic Insects of Michigan
13.Parker D. (-2012) AquaTax Consulting
14.Clifford H.F. (1991) Aquatic invertebrates of Alberta
15.Phylogeny and systematics of Diptera: Two decades of progress and prospects
Yeates D.K., Wiegmann B.M., Courtney G.W., Meier R., Lambkin C., Pape T. 2007. Zootaxa 1668: 565–590.
16.History of insects
Rasnitsyn A.P., Quicke D.L., eds. 2002. Kluwer Academic Publisher Dordrecht, xii + 517 pp.
18.The Diptera Site