Sepsis
This record describes Sepsis (genus). Recorded family: Sepsidae. Recorded order: Diptera.
Identification and Appearance
This genus of small flies (2-4 mm) are ant mimics. The are 24 species in the genus and whilst the species can be determined with a good key it is almost impossible to identify them without microscopic examination of the specimen. The genus is generally easy to recognise however by the dark spots near the end of each wing (in British species, there are European species such as S. lateralis which lack these spots). If you wish to take your determination beyond genus to species you will need a good quality image of the spines along the underside of the front femora for males. Females need their dusting patterns and abdominal bristles to be checked under a microscope if you wish to reach a species determination. These flies is can be seen visiting flowers on order to obtain a carbohydrate meal, but are most often associated with animal dung, particularly that of cows and horses. Often groups of these flies 'dance' on a leaf, waving wings and legs.
Classification
Habitat and Range
Habitat
These flies is can be seen visiting flowers on order to obtain a carbohydrate meal, but are most often associated with animal dung, particularly that of cows and horses. Often groups of these flies 'dance' on a leaf, waving wings and legs.
Seasonal Activity
Can be seen most months of the year.
Additional species information
Recorded status
Common and widespread in Britain.
About Flies: the wider group
Order-level background for Diptera, the group containing Sepsis. 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 Sepsis (9)
Frequently Asked Questions About Sepsis
What is Sepsis?
Sepsis is a genus in the family Sepsidae, within the order Diptera.
Where is Sepsis found?
Habitat: These flies is can be seen visiting flowers on order to obtain a carbohydrate meal, but are most often associated with animal dung, particularly that of cows and horses. Often groups of these flies 'dance' on a leaf, waving wings and legs.
When is Sepsis active?
Sepsis: seasonal activity - Can be seen most months of the year..