Splayed Deerfly
Chrysops caecutiens
This record describes Chrysops caecutiens (species). Recorded family: Tabanidae. Recorded order: Diptera.
Identification and Appearance
Length 8.5 to 10 mm. The females have a characteristic splayed v-shaped marking on tergite 2. Males have the abdomen almost entirely black, though tergite 2 is narrowly orange at its sides; the male mid tibiae are normally entirely black. It can occur in a variety of habitats but often in damp or well wooded places. The predatory larvae live in wet mud and debris at the edges of streams and pools. This is one of our two frequent deerflies and with a strongly developed taste for human blood. Widespread and fairly frequent in much of England and Wales, though less common from Cumbria northwards. Chrysops ID Guide - Soldierflies and Allies Recording Scheme Chrysops caecutiens - Influential Points
Wikipedia reference for Chrysops caecutiens: http://en.wikipedia.org/wiki/Chrysops_caecutiens.
Classification
Habitat and Range
Habitat
It can occur in a variety of habitats but often in damp or well wooded places.
Seasonal Activity
They are active from May to September
Diet and Behavior
Life History
The predatory larvae live in wet mud and debris at the edges of streams and pools. This is one of our two frequent deerflies and with a strongly developed taste for human blood.
Additional species information
Recorded status
Widespread and fairly frequent in much of England and Wales, though less common from Cumbria northwards.
About Flies: the wider group
Order-level background for Diptera, the group containing Chrysops caecutiens. Species-specific details appear above.
Group overview
Diptera includes over 150,000 described species of flies, mosquitoes, and midges. Mosquitoes are the deadliest animal on Earth (CDC). Malaria alone causes ~249 million cases and over 608,000 deaths annually, mostly children under 5 (WHO). Vector-borne diseases account for over 17% of all infectious diseases, causing 700,000+ deaths per year.
Ecological role of the group
Despite their disease impact, flies are critical decomposers and pollinators. Hoverflies alone pollinate hundreds of crop and wildflower species. Flies are also the primary food source for many birds, bats, and fish. Forensic entomology relies heavily on fly species for crime scene analysis.
Economic and practical significance of the group
In the U.S., vector-borne disease cases tripled between 2004-2016, with over 640,000 cases reported in that period (CDC). Tickborne diseases doubled from 22,000 to 48,000 annual reports. Globally, mosquito-borne diseases cost billions in healthcare and lost productivity.
Recorded sources for this group: WHO, CDC, PNAS. Imported estimates may describe particular regions or reporting periods.
Photos of Splayed Deerfly (3)
Frequently Asked Questions About Splayed Deerfly
What is Splayed Deerfly?
Splayed Deerfly (Chrysops caecutiens) is a species in the family Tabanidae, within the order Diptera.
How big is Splayed Deerfly?
8.5 to 10 mm. The females have a characteristic splayed v-shaped marking on tergite 2. Males have the abdomen almost entirely black, though tergite 2 is narrowly orange at its sides; the male mid tibiae are normally entirely black.
Where is Splayed Deerfly found?
Habitat: It can occur in a variety of habitats but often in damp or well wooded places.
When is Splayed Deerfly active?
Splayed Deerfly: seasonal activity - They are active from May to September.
What is the life cycle of a Splayed Deerfly?
The predatory larvae live in wet mud and debris at the edges of streams and pools. This is one of our two frequent deerflies and with a strongly developed taste for human blood.