Descriptions of Families
of Flower-Visiting
Flies
Anthomyiidae (Anthomyiid Flies, Dung Flies)
The adults are generally greyish with black dots, resembling the Muscid flies. They occasionally feed at flowers with exposed nectaries, such as members of the Carrot family. The larvae have various habits, sometimes feeding on dung, scavenging in bird nests, and other rotting materials. The larvae of some species feed on bulbs, and can become pests of onions and lilies.
Bibionidae (March Flies)
These flies are most common during the spring. The males form mating swarms to attract females. They occasionally nectar at wildflowers, shrubs, and small trees that bloom during the spring, sometimes in large numbers, and can be considered minor pollinators of these plants.
Bombyliidae (Bee Flies)
Bee flies are large, fat, and hairy, often with a long, rigid proboscis. They are excellent mimics of bees, and may have black and yellow stripes along the abdomen. The adults are avid seekers of nectar from various flowers, although a few species feed on pollen. They are important pollinators, and can reach the nectaries of many wildflowers that are inaccessible to other flies. Their larvae are brood parasites on various species of bees and wasps.
Calliphoridae (Blowflies, Bottle Flies, Calliphorid Flies)
These stout flies are medium to medium-large sized, and are often colored metallic green (e.g., Lucilia spp.) or metallic blue (e.g., Calliphora spp.). The adults feed from flowers with exposed nectaries, while the larvae feed on rotting carcasses. A few species can become pests of livestock because they lay their eggs around the orifices of such animals.
Ceratopogonidae (Biting Midges)
The adults are gnats that consume other small insects or bite warm-blooded animals. In addition to these activities, they also visit flowers with exposed nectaries, but aren't important pollinators. The larvae live in moist ground where there is a suitable amount of decaying organic material.
Conopidae (Thick-Headed Flies)
These wasp-like flies like to bask in the sun, and often obtain nectar from various flowers. The heads of some species are unusually wide. The larvae are parasitoid on various species of bees and wasps. The adult females sneak up on these hymenoptera during flight and lay an egg on the abdominal region. Thick-Headed flies are fairly effective pollinators of many wildflowers, but are less common visitors than Syrphid or Tachinid flies.
Culicidae (Mosquitoes)
Adult mosquitoes occasionally obtain nectar at flowers, but they are not significant pollinators in temperate climates. Their larvae breed in water, while the females require a blood-meal from warm-blooded animals in order to lay numerous eggs. Mosquitoes can transmit numerous diseases to humans.
Milichiidae (Milichiid Flies)
These are small, often tiny, blackish flies, whose larvae breed in dung, or scavenge in burrows and nests. The adults visit flowers with exposed nectaries, but they are rarely important pollinators, except when very numerous.
Muscidae (Muscid Flies)
These stout, medium-sized flies are grey or black, with darker stripes and other patterns. The species Musca domestica (Common Housefly) is a typical example. Larvae are opportunists that feed in decomposing organic debris, preferably with some animal matter. The adults occasionally visit flowers with exposed nectaries, particularly in the Carrot family. A few species, such as Stomoxys calcitrans (Stable Fly), will bite warm-blooded animals, seeking blood or salty perspiration.
Otitidae (Otitid Flies, False Fruit Flies)
These small slender flies resemble fruit flies, but their larvae feed in decaying vegetable matter or dung, rather than fruit. The adults occasionally feed at flowers with exposed nectaries, but they are only minor pollinators.
Sarcophagidae (Flesh Flies)
These are rather nondescript flies with checkered grey patterns, resembling Muscid flies, except they are a bit larger in size. The adults occasionally feed from flowers with exposed nectaries. The rather large larvae feed on rotting carcasses, as might be expected from the common name for this family.
Sciaridae, Mycetophilidae (Fungus Gnats)
The small gnat-like adults occasionally visit flowers with exposed nectaries, but they are not important pollinators. The larvae feed on decaying vegetable matter, or bore holes through fungi.
Stratiomyidae (Soldier Flies)
These large flies are long and slender, sometimes with metallic colors and spines along the thorax. The adults are lethargic, but nectar at flowers occasionally. They are most often observed in moist sunny places. The larvae of the larger Soldier Flies, such as Stratiomys & Odontomyia spp., are carnivorous, feeding on worms, small crustacea, and insects in moist ground. The larvae of other species feed on decaying vegetable matter along streams and other wet places. Soldier flies are good pollinators, but they are not very common.
Syrphidae (Hover Flies, Flower Flies, Syrphid Flies, Drone Flies)
These are small to medium-sized flies that can hover motionless in the air. They usually mimic bees or wasps, often with black and yellow stripes along the abdomen. The proboscis is short, therefore Syrphid flies tend to visit smaller flowers with short nectar tubes in sunny places. At larger flowers, some Syrphid flies feed on stray pollen, while other species are attracted to salty perspiration. These latter species are sometimes called "Sweat Bees," which is a misnomer. Depending on the species, the larvae feed on aphids and other insects, or they may scavenge for dead animal material in moist soil, or they may feed in water that is rich in organic decomposition. There are numerous species in this family. As a group, Syrphid flies are probably the most common and important pollinators of prairie wildflowers among the various families of flies.
Tabanidae (Horseflies, Deer Flies)
The Chrysops spp. (Deer flies) are fairly large and often brightly patterned in yellow and black. They favor open woodlands and bite deer and other warm-blooded animals. The larvae feed on decaying vegetable matter in shallow water. The adults may obtain nectar from flowers, but they are not important pollinators. Horseflies are even larger, and found in pastures or prairies where there are large hoofed animals. They bite these animals to lap their blood. Their larvae occur in muddy areas and are carnivorous. The adult Horseflies are more likely to use flowers as a place to perch, than anything else.
Tachinidae (Tachina Flies, Tachinid Flies)
These are stout flies, medium to large, that are very bristly, particularly around the posterior of the abdomen. They are often grey with checkered patterns, but sometimes appear solid black or brown. The larvae are parasitoid on numerous other insects, including spiders and millipedes. The adults are avid feeders on nectar. There are many species in this family, and they are common visitors of many prairie wildflowers.
Tephretidae, Drosophilidae (Fruit Flies)
These small, delicate-looking tan or brown flies occasionally suck nectar from flowers, but they are more likely to visit rotting fruit or fermenting sap. They are insignificant pollinators of flowers. The larvae feed on fruit, and can become a nuisance in orchards.