Mosillus bidentatus
This record describes Mosillus bidentatus (species). Recorded family: Ephydridae. Recorded order: Diptera.
Identification and Appearance

Face with a pair of small, white spots between antennae and eyes. Other North American species have a large white area instead of small spots.
Classification
- Kingdom
- Animalia
- Phylum
- Arthropoda
- Class
- Insecta
- Order
- Diptera (Flies)
- Superfamily
- Ephydroidea
- Family
- Ephydridae (Shore Flies)
- Subfamily
- Gymnomyzinae
- Genus
- Mosillus
Imported taxonomy record. Source availability varies; see the source references and editorial policy below.
Habitat and Range
Geographic Range
Western North America, with occasional records east to Michigan.
About Flies: the wider group
Order-level background for Diptera, the group containing Mosillus bidentatus. 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 Mosillus bidentatus (5)
Photo credits: Contributed by John F. Carr
Frequently Asked Questions About Mosillus bidentatus
What is Mosillus bidentatus?
Mosillus bidentatus is a species in the family Ephydridae, within the order Diptera.
How do you identify Mosillus bidentatus?
Face with a pair of small, white spots between antennae and eyes. Other North American species have a large white area instead of small spots.
Where is Mosillus bidentatus found?
Range: Western North America, with occasional records east to Michigan.
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