Flies, gnats, maggots, midges, mosquitoes, keds, bots, etc. are all common
names for members of the order Diptera. This diversity of names documents the
importance of the group to man and reflects the range of organisms in the order.
The order is one of the four largest groups of living organisms. There are more
known flies than vertebrates. These insects are a major component of virtually
all non-marine ecosystems. Only the cold arctic and antarctic ice caps are
without Flies. The economic importance of the group is immense. One need only
consider the ability of flies to transmit diseases. Mosquitoes and black flies
are responsible for more human suffering and death than any other group of
organisms except for the transmitted pathogens and man! Flies also destroy our
food, especially grains and fruits. On the positive side of the ledger, outside
their obviously essential roles in maintaining our ecosystem, flies are of
little direct benefit to man. Some are important as experimental animals
(Drosophila) and biological control agents of weeds and other insects. Others are crucial in helping to solve crimes (for an example click here).
Some 120,000 different kinds of flies (Order Diptera, Class Insecta, Phylum
Arthropoda) are now known and estimates are that there may be more than
1,000,000 species living today. These species are classified into 188 families
( For a list of
recognized families) and some 10,000 genera. Of these, some 3,125 species
are known only from fossils, the oldest of which, a limoniid crane fly, is some
225 MILLION years old (Upper Triassic (Carnian)). (See the Databases of World
Diptera for the names of flies and information on those names and groups of
A basic introduction to flies is provided by Harold Oldroyd's Natural
History of Flies (1964, The World Naturalist series, Norton). A more
technical overview and general classification with key to the basic groups
(genera) found in North America is provided by the Manual of Nearctic Diptera
(3 vols., 1981, 1987 & 1989, Agriculture Canada). Also see the FLYTREE project for information on the classification of flies.
Short vignettes of various groups of flies are presented above. Each covers a
family of flies, providing an image of a typical species, the range of that
species and the family as whole, with a summary of what is known about the
group. These family pages may lead to even more information about small groups
(genera) of flies and eventually to information about species of flies.
Information about flies at this site is arranged into 3 levels, which correspond
to the family, genus and species categories.
Most of the family treatments are still under construction: Currently there
being only an image of a typical species. Select flower
flies or milichiid
flies to see treatments which extend to all levels of diversity, from the
family to the species. Also, the treatments for primitive crane
flies and eurychoromyiid
flies are complete. You can also find lots of information on Tephritidae
(fruit flies) by clicking here.
Also visit the Young