There are about 17,000 species of flies. Many of them have aquatic larva. These include but are not limited to; black flies, crane flies, gnats, some horseflies, hover flies, midges, mosquitoes, and no-see-ums.
The larva are generally wormlike in appearance. Many, but not all, are inactive and either lacking legs, or having inconspicuous legs. They often have hard short bodies, that sometimes are in a case. Most fly larva don't have a distinct head and are lacking eyes. The larval stage can last from a few weeks to several years.
The larva often live on the surface or on the bottom of the water in debris and mud.
Adult flies are not aquatic. Some can grow up to 1 1/2 inches long. They can have a soft or leathery body, often covered with bristles. Flies have globular heads with large eyes and antennae which are often small. Their mouth parts are made for lapping, piercing or sucking. Some, like the mosquito, have a long proboscis. Flies have an oval thorax and a humped back. They have membranous forewings that are transparent and nearly veinless. The hind wings are often modified into knob-like balancing organs.
There are about 140 species of black fly. Their larva live in fast flowing water, attaching to rocks in groups with a sucking disk located near the tail and by a silken line. They feed on micro organisms drawn into themselves by water currents created by fan like growths on their heads. The larva pupate in underwater cocoons.
Adult black flies are small and stout with a humped back, growing up to 1/4 inch. They are colored grey to black with short legs that are often colored yellow. They have large wings for their body size, on broad bases.
Female black flies bite and feed on birds and mammals, including people.
Crane flies are often mistaken for giant mosquitoes. Though they look like the biting pest they are actually harmless and do not bite. Crane flies have very long legs, and are somewhat clumsy in movement and flight. They are marked with a v-shaped line on their thorax between the wings.
Crane flies are widely distributed in North America, with over 1500 species. They're attracted to lights, and can often be found flying around porch lights at night. Crane flies often don't eat at all in their adult lives, those that do feed on nectar.
Not all crane fly larva live in water, some live in the soil. For those that do live in water, the female crane fly lays her eggs in the water after mating in flight.
Crane fly larva can be predaceous or vegetarian in nature. They breath air by thrusting their tails through the surface of the water.
Also called no-see-ums, biting midges and punkies, these are tiny flies, up to 1/4 of an inch. They have small heads and long legs and wings are large for the size of the fly and fold over the back. They look a lot like mosquitoes. As with many other biting flies the females do bite. Like the non-biting midges the males have a feathery antennae, unlike the females.
Members of this family feed on other midges, dragonflies, butterflies, and other animals including humans.
Larva can be aquatic or semi-aquatic. They're slender and worm like. The popular live food the glass worm, pictured at left, is the larva of a gnat from the family Chaoboridae.
Glass worms are popular as live foods because they are easy to collect in the north in frozen lakes and ponds, and can keep for extended periods of time if kept cold.
When the glass worms start warming up they will pupate, like the one pictured to the right, and eventually turn into gnats. The pair pictured farther above are the adult gnats that developed from glass worms.
Horse flies are large bristleless green flies most known for their nasty bites. Female horse flies will bite humans, horse, deer and cattle. There are about 350 species ranging from 1/4 to 1 1/4 inches long. Some have aquatic larva.
There are about 870 species of hover fly ranging from 1/2 to 3/4 inches. These flies are striped black and yellow, mimicking the color of bees and wasps, though the hover fly is harmless. They have large eyes and a short proboscis,. Hover flies have a false vein on their wings that doesn't link with other veins.
These flies are quick and active, darting and hovering in mid air. They feed on pollen and nectar and are beneficial pollinators.
Some hover fly larva are aquatic. They are recognizable due to their long tails.
Midge larva are almost all aquatic. Some of the most commonly known to aquarists are bloodworms. The larva live in streams, rivers and ponds. They make a tube in the mud at the bottom of the water. Their bodies are soft and worm like, and often bright red.
Blood worms make a good fish food. I often find them in my kiddie pools and live food cultures outside. I feed them to my fish. They are often also sold as live food, frozen, freeze dried and in flakes.
Adult midges are small and fragile, only growing up to 1/2 inch long. There are about 820 species. The male and female midge are visibly different. Males have feather like antennae, while females antennae are more hair like.
The mosquito is probably the most well known fly that has an aquatic larval period. There are more than 1600 kind of mosquito world wide. Over 120 species in North America, 200 in Australia and 36 in Great Britain. Some mosquitoes can transmit diseases to humans, including malaria, yellow fever and degue fever.
Only female mosquitoes sting. The initial pain from the bite is from a fluid being into the victim through the mosquitoes long piercing proboscis. The fluid prevents blood coagulation, it's also what causes later itchiness. Immunity may eventually be reached for the later itchy period. Males eat fruits and nectar.
Mosqitoes are between 1/4 and 1/2 inch long. They place their wings over their backs when resting. And raise their hind legs. They are most active at dusk and dawn in areas where there are standing bodies of water.
The female mosquito can lay as many as 300 eggs in little floating sacs known as egg rafts. All mosquito larva and pupae are aquatic. Larva are between .2 and .5 inches long. They will live in almost any standing body of water.
Both the larva and pupa take in oxygen through surface of the water where they float. If the water surface is disturbed they will wiggle down to the bottom, using leaflike tail appendages. Their heads and thorax are fused.
Mosquito larva eat by filtering the water for microscopic plants, animals and edible debris through brushes that surround their mouths.
The larva is another great fish food. Being so common they are eaten by fish all over the world. They are also preyed on by other insects that are predacious. Birds, dragon flies and frogs are some of the animals that eat adult Mosquitoes.
| Moss Animals
| Leeches, Worms, and Planaria
| Small Crustaceans
| True Bugs
| Ramshorn Snails
| Pond Snails
| Malayan Livebearing Snails