Flies in Colorado

This page is for the families within the Diptera order
Family Asilidae Robber flies, or Assassin flies.
Family Tipulidae. Crane flies.
Family Muscidae House flies
Family Calliphoridae Blow flies
Family Chironomidae Midges
Family Tabanidae Horse and Deer flies
Family Tachinidae Tachina flies, or Tachinids
Family Bombyliidae Bee flies
Family Culicidae Mosquitoes
Family Unknown Unknown flies

This is a lady Crane Fly. Picture taken 11 Jun 2008, resting on a leaf of the Virginia Creeper vine. It is about 3/4" long, not counting the long legs.

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Suborder: Nematocera
Infraorder: Tipulomorpha
Family: Tipulidae (crane flies)
Subfamily: Tipulinae
Genus: Nephrotoma (Tiger Crane Flies)

Two years later, almost to the day, here is a pair of Crane flies doing their thing on the same Virginia Creeper vine, at just about the same location in the vine. Picture taken 10 June 2010.

This one has some similarities to a Crane Fly, mostly the long legs. It was found on 29 August 2009 early in the morning, when the illumination was just one small CF bulb. I came back later after the sun was up, but the fly had departed.


Family Muscidae, House flies

House Fly, picture taken 13 July 2008 in Colorado Springs. The second picture was taken 18 June 2008, in Colorado Springs, and shows eggs that have been laid in the dog's food dish. The eggs are a little over 1 mm in length. The larvae (maggots) will hatch in less than a day, and grow to a length of 3 - 9 mm in length. Later, the maggot will transform into pupae, and adult flies will emerge from the pupae. A female fly will be ready for mating within about 36 hours.

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Family: Muscidae
Genus: Musca
Species: M. domestica


A pair of flies, identification not done yet. Seen at the Fountain Creek Nature Center on 28 June 2009.

Family Calliphoridae, Blow flies

A Blow-fly, AKA Blow Fly or Blowfly. More specically, it is probably a Green Bottle Fly. Picture taken 12 July 2008 in Colorado Spring, Colorado. The back is uniformly green; my camera made it look two-toned.

The identification was made by the folks at www.bugguide.net.

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Suborder: Brachycera
Infraorder: Muscomorpha
Subsection: Calyptratae
Superfamily: Oestroidea
Family: Calliphoridae (blowflies)
Subfamily: Luciliinae
and probably genus Lucilia (green bottle fly)


Family Tabanidae, Horse and Deer flies

A Horse Fly. This was a large male, between 3/4" and 1" not counting legs. The picture was taken in El Paso County, Colorado on 15 July 2008. There are about 350 species of Horseflies in North America, and about 3,000 world wide. This species is the Western Horse Fly, Tanabus puncitifer.

Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Subclass: Pterygota
Infraclass: Neoptera
Superorder: Endopterygota
Order: Diptera
Suborder: Brachycera
Superfamily: Tabanomorpha
Family: Tabanidae (Horse and Deer flies)
Genus: Tanabus
Species: punctifer

Another Western Horse Fly, this one at the Fountain Creek Nature Center on August 3, 2016.


Family Bombyliidae, Bee flies

This is a Bee Fly. This family of flies are called Bee Flies because by evolution, they have taken on the appearance of a bee, and hence avoid being eaten by predators that avoid bees. They do not have stingers. It is about 3/8" long, at the Fountain Creek Nature Center on 20 September 2008. There are several species in the genus Poecilanthrax, but maybe this is willistonii.

Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Subclass: Pterygota
Infraclass: Neoptera
Superorder: Endopterygota
Order: Diptera (true flies)
Family: Bombyliidae (Bee Flies)
Genus: Poecilanthrax
Species: willistonii (maybe)

Another Bee fly, this one in the Genus Anastoechus. Species not determined yet. It is about 1/4" long, at the Fountain Creek Nature Center on 20 September 2008.

Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Class Insecta (Insects)
Order Diptera (Flies)
Superfamily Asiloidea
Family Bombyliidae (Bee Flies)
Subfamily Bombyliinae
Tribe Bombyliini
Genus Anastoechus

More Bee flies, these found on 2 October 2009 in a Marigold patch in Colorado Springs, CO. Identified as flies since they have two wings, not four, and as Bee Flies since they look like bees. Further identification has not been made yet.
This Sinuous Bee Fly was indentified by Ron Hemberger on www.Bugguide.net. This was found on 17 July 2013 in Colorado Springs, CO.

Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Class Insecta (Insects)
Order Diptera (Flies)
No Taxon (Orthorrhapha)
Superfamily Asiloidea
Family Bombyliidae (Bee Flies)
Subfamily Anthracinae
Tribe Villini
Genus Hemipenthes
Species: Sinuosa


Family Tachinidae. Tachina flies, or Tachinids. Over 1,300 species in North America alone.

According to the folks on www.bugguide.net, this is a Tachinid Fly, a member of the Tachinidae family. It was found in Cripple Creek, Teller Co. CO on 3 July 2012 attracted to the thistle. Identification down to genus and species is by me, based on photos on the internet.

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Suborder: Brachycera
Subsection: Calyptratae
Superfamily: Oestroidea
Family: Tachinidae
Genus: Hystricia
Species: abrupta



Family Culicidae, Mosquitoes

Mosquito. This photo was taken on 20 August 2008 at the Fountain Creek Nature Center, from one of their ponds. It is a larva, about 1.5mm long, so it barely fit in the field of view of my microscope at x100 magnification. There are about 40 genera, and over 150 species in the United States alone.

The larva hatched from an egg, and in turn will transform into a pupa, which in turn will result in an adult mosquito, which in turn will lay more eggs. A male mosquito will live only about a week, while the female mosquito, the only one that bites, will live about a month.

Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Hexapoda
Class: Insecta
Subclass: Pterygota
Infraclass: Neoptera
Superorder: Endopterygota
Order: Diptera
Suborder: Nematocera
Infraorder: Culicomorpha
Superfamily: Culicoidea
Family: Culicidae

This is the larva of some variety of Mosquito. It is about 3mm in length. When I first saw it, I thought it was a mosquito larva, since it is about the same size and had the same jerky motions. But it lacks the air tube at the tail end that is visible in the photo above. I am still researching this, but I believe that at some stages of development, the air tube drops off.

It came from the Mosquito pond at the Fountain Creek Nature center on 25 July 2009. I used a Canon DSLR camera with the lens on a bellows extension for close-up work.




Family Asilidae, Robber flies or Assassin flies.

This one was found near 11 Mile Lake on June 27, 2017. It flew and landed like a grasshopper or locust, but looked more like a fly. The experts at www.Bugguide.net identified it as belonging to the family of Asilidae, Robber flies or Assassin flies. It was at least 3 cm in body length. Maybe further study can narrow it down to genus and species. This family has over 7000 described species, according to Wikipedia.

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Suborder: Brachycera
Infraorder: Asilomorpha
Superfamily: Asiloidea
Family: Asilidae (Robber flies)



Family Chironomidae, Midges

This is a Midge fly, found on 7 June 2011 at Eleven Mile Lake, Park co., CO. This is only one of many hundreds of thousands, if not millions that were flying around that day. I do not have an identification down to the genus and species level. Body length about 1cm. Common names are Midge, Gnat, Cranefly, Snow fly, Blood Worm, Deer Fly, Black Fly, and Mosquito.

The second and third pictures are some that rode along with me on my boat on Eleven Mile Lake, 17 June 2011.

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Suborder: Nematocera
Family: Chironomidae (Midges)
Genus: there are maybe 175 Genera, and 1000 species.



These are Midge flies, found on 8 April 2012 in Colorado Springs. Many of them were in my gazebo, trying to escape from the netting, late in the day. The experts on www.bugguide.net say that this is a male in the Chironomini tribe. An identification down to genus and species would need a more detailed examination. Body length about 5mm.

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Diptera
Suborder: Nematocera
Family: Chironomidae (Midges)
Subfamily: Chironominae
Tribe: Chironomini




Unknown flies

This would be the larva of some fly. It was found at the Fountain Creek Nature Center on July 18, 2014. It was crawling or digging in the gravel of one of the hiking trails near one of the lakes. I thought it was a centipede until I noticed that all the legs were at one end. My camera did not focus precisely. It was about 1" long. Identification has not been made yet.