Diptera is both a very abundant and diverse order. As their name suggests, flies are excellent fliers. Unlike most insects, they only have one set of membranous wings. Their hind wings have evolved over time into structures known as “halteres,” small knob-like structures responsible for balance.

Fly larvae are found in a wide range of habitats and have diverse food habits eating plant tissue, dead and living animal tissue, decaying organic matter, blood, other insects, etc. Adults feed mainly on liquids, often from sweet or decaying sources. Flies are also important pollinators of native plants and crops.

The most common flies at the reserve are two species of kelp flies, Fucellia costalis and Coelopa vanduzeei. The larvae, together with the beach hoppers, are responsible for the breakdown of the kelp that washes on the beach. The adult flies occurs in huge number in and around kelp wrack. These flies are an important food source to many shorebirds, including the threatened Western Snowy Plover.

The most curious of our flies is the petroleum fly, Helaeomyia petrolei. This fly spends its entire larval stage submerged in pools of crude oil, feeding on insects that fall into the oil. We do not know much about the population of petroleum flies at Coal Oil Point, but we expect that the reserve provides good habitat for them, as crude oil is common on the beach and around the dune pond.

Flies are responsible for a great deal of the diversity at Coal Oil Point, with over 120 species in the collection.

Fly Photos (click to enlarge)
Tipulidae - Crane Flies
Bibionidae - March Flies
Dilophus sp.	Bibiodes sp. (female)	Bibiodes sp. (male)
Sciaridae - Dark-winged Fungus Gnats
Cecidomyiidae - Gall Gnats
Additional pictures and information about Cecidomyiidae
Mycetophilidae - Fungus Gnats
Psychodidae - Moth Flies
Scatopsidae - Minute Black Scavenger Flies
Culicidae - Mosquitoes
Culex sp.
Chironomidae - Midges
Additional information about Chironomidae
Therevidae - Stilleto Flies
Asilidae - Robber Flies
Bombyliidae - Bee Flies
Empididae - Dance Flies
Dolichopodidae - Long-legged Flies
Syntormon sp.
Additional information about Dolichopodidae
Phoridae - Humpbacked Flies
Syrphidae - Flower Flies
Additional pictures and information about Syrphidae
Pipunculidae - Big-headed Flies
Acalyptratae ?
Lonchaeidae - Lonchaeid Flies
Setisquamalonchaea fumosa
Tephritidae - Fruit Flies
Coelopidae -Kelp Flies
Coelopa vanduzei
Piophilidae - Skipper Flies
Mycetaulus sp.
Agromyzidae - Leaf Miner Flies
Additional pictures and information about Agromyzidae
Lauxaniidae - Lauxaniid Flies
Heleomyzidae - Heleomyzid Flies
Sphaerociidae - Small Dung Flies
Leptocera sp.
Curtonotidae - Curtonotid Flies
Axinota sp. (?)
Ephydridae - Shore flies
Petroleum fly Helaeomyia petrolei	Petroleum fly (larva) Helaeomyia petrolei	Atissa sp. (?)
Chloropidae - Grass Flies
Additional pictures and information about Chloropidae
Anthomyiidae - Anthomyiid Flies
Muscidae - House Flies
Additional pictures and information about Muscidae
Calliphoridae - Blow Flies
Sarcophagidae - Flesh Flies
Tachinidae - Tachinid Flies
Additional pictures and information about Tachinidae