Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Subclass: Dicondylia
Infraclass: Pterygota
Superorder: Neoptera
Order: Diptera
Suborder: Nematocera
Infraorder: Bibionomorpha
Superfamily: Bibionoidea
Family: Bibionidae
Genus: Dilophus
Common name: March flies, Blossom flies
There are about 200 species in the world. Their habitat is on land, and often by water. They are found from lowlands to alpine zones.
Flies of the Dilophus genus usually prefer open habitats, such as grasslands, meadows and cultivated fields, they are rarer in forests. They can be very numerous. The larvae feed in dense accumulations. The larvae eat mostly decaying plant material but can also be found in manure, for example in cow paddies. Some species can do damage by their larvae eating the roots of various plants, on the other hand, these numerous flies are food for many different animals. The adult flies often visit flowers to eat nectar and pollen and may have some importance as pollinators. They can be active both during the day and at night time. The males fly happily a few meters above the ground with their abdomen displaying a characteristic bend like a hook. They can swarm.
Photos below are a female 4mm fly in the genus Dilophus.
Thanks to Wikipedia for text and information http://creativecommons.org/licenses/by-sa/3.0/