Unlike the other insects, I had to learn more about the taxonomy of flies in order to understand what I was reading. When studying flies, they are divided into two suborders, 1) Nematocera, which are the lower order flies, and 2) Brachycera, which are the higher order flies and also the short-horned flies. The Nematocera are then divided into the aquatic families and the terrestrial families.
Diptera evolved from aquatic life histories and even as some became terrestrial, their eggs are aquatic for some portion of the egg history. The aquatic life has its benefits. Water circulates more freely bringing more food to the larvae more easily than those living in soil. The result is that soil dwellers take longer to develop.
Less than half of the flies in the world are known, described, and named; their larvae even less so, with an estimated 5% of them recognized.
Diptera larvae are extremely variable in their appearance. The variation is so great that there is no one characteristic or combination of characteristics that allow a person to tell them from other larvae that go through the same type of metamorphosis. The one common character fly larvae have is the absence of jointed thoracic legs, but this is also found in other orders. Often if one finds a slender larvae moving in one direction, it could be in a Diptera.
Habitat is another highly variable element of Diptera larvae. There are aquatic ones that live in just about any place that water is present, regardless of whether it is fresh water or polluted. Terrestrial larvae can be found in living plants, galls, or decaying plant and animal matter. Some larvae are parasitic; some are predaceous.
Flies taste with their feet. When they land on plants, they are looking for the honeydew left by other insects. Their darting and dashing about is in search of this sweet liquid. They smell with their antennae.
Adult flies do not have chewing mouthparts and therefore are considered to be partners of plants since they rarely damage the foliage, seeds, stems, or flowers. This cannot be stated for many fly larvae. Leaf-mining is damage to the leaf that most of us are familiar with; this is usually the work of a fly larvae, a beetle larvae, or a moth caterpillar. It’s also an easy way to identify the flies as leaf-miners are plant specific with a unique mining pattern.
If you haven’t spent much time studying flies and bees, they can look very similar. A couple of easy ID traits to keep in mind are:
1) flies wings are out to their side when at rest; bees are folded over their body
2) flies have one set of wings; bees have two
3) Antennae on flies are short and stubby; bees are long
Male and female flies can be distinguished by their eyes. Males have large eyes that meet in the middle while female eyes are separate.
The evolution of flies has been rather slow until the 1850s. Since then, man has been one of the strongest forces exerting change on our insects because present-day man is altering the face of earth by destroying forests, cultivating prairies, spraying insecticides, and killing game animals faster than his ancestors could. This is a rather sobering statement!
Diptera are difficult to ID so I’m feeling pretty lucky to have some of the genera known even though they are unable to ID’d down to the species level. Many of them do not have a common name. Where I have found one, I have included it, otherwise they are listed by their genus and alphabetized as such. Because of awesome specialists at BugGuide, every effort has been made to ensure that the ID’s are accurate but if there is an error, please let me know. The information obtained on each family and/or fly can be found in this list of references.
Anisopodidae (Wood Gnats)
Sylvicola (subgenus Anisopus) sp
Anthomyiidae (Root-Maggot Flies)
Asilidae (Robber Flies)
Laphria sericea-aktis complex
Bombyliidae (Bee Flies)
Anthrax georgicus – Black Bee Fly
Hemipenthes sinuosa – Sinuous Bee Fly
Calliphoridae (Blow Flies, Screwworms, and Cluster Flies)
Cochliomyia macellaria – Secondary Screwworm
Phormia regina – Black Blow Fly
Pollenia sp – Cluster Fly
Cecidomyiidae (Gall Midges and Wood Midges)
Ceratopogonidae (Biting Midges)
Biting Midge – Culicoides sp
Chironomidae (Non-Biting Midges)
Cricotopus subgenus Isocladius
Chloropidae (Grass Flies)
Conopidae (Thick-headed Flies)
Aedes vexans – Inland Floodwater Mosquito
Dolichopodidae (Long-legged Flies)
Condylostylus sp comatus group
Drosophilidae (Vinegar Flies)
Empididae (Dance Flies)
Heleomyzidae (Wombat and Cave Flies)
Hybotidae (Hybotid Dance Flies)
Hybotid Dance Fly – Platypalpus sp
Limoniidae (Limonid Crane Flies)
Micropezidae (Stilt-legged Flies)
Muscidae (House Flies and kin)
Mycetophilidae (Fungus Gnats)
Oestridae (Bot Flies)
Cuterebra fontinella – Mouse Bot Fly
Psychodidae (Moth and Sand Flies)
Pyrgotidae (Scarab-killing Flies)
Pyrgota undata – Waved Light Fly
Rhageonidae (Snipe Flies)
Chrysopilus thoracicus – Golden backed Snipe Fly
Rhagio mystaceus – Common Snipe Fly
Sarcophagidae (Flesh and Satellite Flies)
Flesh Fly – Sarcophaga sp
Sciaridae (Dark winged Fungus Gnat)
Sciomyzidae (Marsh Flies)
Sepsidae (Black Scavenger Flies or Antlike Scavenger Flies)
Syrphidae (Flower Flies)
Eristalis tenax – Drone Fly
Eristalis transversa – Traverse Flower Fly
Tabanidae (Horse & Deer Flies)
Tachinidae (Feather-legged Flies)
Tephritidae (True Fruit Flies)
Euaresta festiva – Festive Fruit Fly
Eurosta solidaginis – Goldenrod Gall Fly
Tipulidae (Giant Crane Flies)
Tipula abdominalis – Giant Crane Fly
Tipula fuliginosa – Sooty Crane Fly
Ulidiidae (Picture-winged Flies)