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- ›Chrysopsini
Deer Flies
Chrysops
Deer flies (also known in some parts of the mid-Atlantic United States as sheep flies) are bloodsucking insects considered pests to humans and cattle. They are large flies with large brightly coloured compound eyes, and large clear wings with dark bands. They are larger than the common housefly and smaller than the horse fly. There are 250 species of deer fly in the genus Chrysops. Their distribution is worldwide, though they have not been reported in Iceland, Greenland, or Hawaii.
Deer flies lay between 100 and 800 eggs in batches on vegetation near water or dampness. During the larval stage, which lasts one to three years, they feed on small creatures or rotting organic matter near or in the water. After a pupal stage, they emerge as adults in late spring and summer. While male deer flies collect pollen, female deer flies feed on blood, which they require to produce eggs. Females feed primarily on mammals. They are attracted to prey by sight, smell, or the detection of carbon dioxide. Other attractants are body heat, movement, dark colours, and lights in the night. They are active under direct sunshine and hours when the temperature is above 22 °C (71.6°). When feeding, the females use scissor-like mandibles and maxillae to make a cross-shaped incision and then lap up the blood. Their bite can be painful. Anti-coagulants in the saliva of the fly prevents blood from clotting and may cause severe allergic reactions. Parasites and diseases transmitted by the deer fly include tularemia, anthrax, anaplasmosis, equine infectious anemia, hog cholera, and filiariasis.
60 branches of this genus, most-observed first
Twin-lobed Deer Fly
speciesChrysops relictus
Striped Deer Fly
speciesChrysops vittatus
Splayed Deer Fly
speciesChrysops caecutiens
Square-spot Deer Fly
speciesChrysops viduatus
Black Deer Fly
speciesChrysops niger
Bothersome Deer Fly
speciesChrysops excitans
Mountain Deer Fly
speciesChrysops montanus
Brownish Deer Fly
speciesChrysops brunneus
Gemeni Deer Fly
speciesChrysops geminatus
Chrysops flavidus
speciesChrysops flavidus
Sacken's Deer Fly
speciesChrysops sackeni
One-striped Deer Fly
speciesChrysops univittatus
Striated Deer Fly
speciesChrysops striatus
Wandering Deer Fly
speciesChrysops aberrans
Beautiful Deer Fly
speciesChrysops callidus
Macquart's Deer Fly
speciesChrysops macquarti
Furious Deer Fly
speciesChrysops aestuans
Chrysops indus
speciesChrysops indus
Chrysops lateralis
speciesChrysops lateralis
Benign Deer Fly
speciesChrysops mitis
Ring-clawed Deer Fly
speciesChrysops cincticornis
Frigid Deer Fly
speciesChrysops frigidus
Adulterous Deer Fly
speciesChrysops moechus
Chrysops celatus
speciesChrysops celatus
Chrysops italicus
speciesChrysops italicus
Dark Deer Fly
speciesChrysops ater
Chrysops dispar
speciesChrysops dispar
Charcoal Deer Fly
speciesChrysops carbonarius
Chrysops divaricatus
speciesChrysops divaricatus
Chrysops fulvaster
speciesChrysops fulvaster
Chrysops discalis
speciesChrysops discalis
Bald Deer Fly
speciesChrysops calvus
Chrysops furcatus
speciesChrysops furcatus
Chrysops pikei
speciesChrysops pikei
Chrysops longicornis
speciesChrysops longicornis
Variegated Deer Fly
speciesChrysops variegatus
Sherman's Deer Fly
speciesChrysops shermani
Venus Deer Fly
speciesChrysops venus
Chrysops nigripes
speciesChrysops nigripes
Chrysops cuclux
speciesChrysops cuclux
Shining Deer Fly
speciesChrysops asbestos
Chrysops flavipes
speciesChrysops flavipes
Chrysops noctifer
speciesChrysops noctifer
Chrysops obliquefasciatus
speciesChrysops obliquefasciatus
Colorado Deer Fly
speciesChrysops coloradensis
Chrysops dawsoni
speciesChrysops dawsoni
Chrysops fuliginosus
speciesChrysops fuliginosus
Chrysops sordidus
speciesChrysops sordidus
Chrysops delicatulus
speciesChrysops delicatulus
Chrysops proclivis
speciesChrysops proclivis
Chrysops rufipes
speciesChrysops rufipes
Chrysops sinensis
speciesChrysops sinensis
Black Deer Fly
speciesChrysops sepulcralis
Chrysops divisus
speciesChrysops divisus
Atlantic Deer Fly
speciesChrysops atlanticus
Chrysops varians
speciesChrysops varians
Chrysops impunctus
speciesChrysops impunctus
Chrysops fixissimus
speciesChrysops fixissimus
Chrysops cinctus
speciesChrysops cinctus
Chrysops dimmocki
speciesChrysops dimmocki
Where it lives
Recorded sightings
—
geo-referenced records in GBIF, from museums, herbaria and field observers.
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In the stacks
Searching the stacks…
Every page naming Chrysops in the Biodiversity Heritage Library →
This page is assembled live from iNaturalist, GBIF, Wikipedia, the Source Library and the Internet Archive. It is not yet part of the hand-edited codex. iNaturalist taxon 49703.