St Mark's Fly vs Western Encephalitis Mosquito
Side-by-side species comparison
| Attribute | St Mark's Fly | Western Encephalitis Mosquito |
|---|---|---|
| Scientific Name | Bibio johannis | Culex tarsalis |
| Order | Diptera | Diptera |
| Family | Bibionidae | Culicidae |
| Size | 6-10mm | 4-6 mm |
| Habitat | Underground | Wetlands |
| Diet | Root Feeders | Blood Feeders |
| Regions | Europe | Western North America, from Canada to Mexico |
| Conservation | Least Concern | Least Concern |
St Mark's Fly
A small black fly that swarms in May. Males have large heads with huge eyes that almost meet on top.
Did You Know?
Often confused with the larger Bibio marci but emerges slightly later and has entirely dark legs.
Western Encephalitis Mosquito
A medium-sized mosquito with a distinctive white band on the proboscis and banded legs. It is the most important vector of Western equine encephalitis and St. Louis encephalitis in western North America. It breeds in a wide variety of sunlit and shaded water sources.
Did You Know?
Its feeding behavior shifts seasonally from birds in spring to mammals in late summer, which drives encephalitis virus spillover to humans.