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.
Explanation of Names
Diptera Linnaeus 1758
Greek 'two-winged' (the name dates back to
Aristotle, who noted the difference from typical four-winged insects
(1)). The English
fly originally signified any flying insect
Numbers
~17,000 spp. in 2,222 genera of ~110 families in our area, the number of described species steadily growing
(2); >150,000 described extant species in ~160 families worldwide
(3)(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.
Identification
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)
Handy diagram of anatomy:
Life Cycle
Larval morphology (brief outlook; McAlister 2014)
Remarks
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
Williston, S. W. 1896. Manual of the families and genera of North American Diptera, 2nd edition. New Haven, J.T. Hathaway. (
Biodiversity Heritage Library)
Internet References
Links to online references for some world fauna, incl. outside of North America:
https://dipterists.org.uk/weblinks
