The species of the genus Parhelophilus resemble those in the genus Helophilus, but are slightly smaller and lack any form of vertical stripe on the face. Bog Flies are found at the edge of (or within a mile of) ponds, lakes, bogs and rivers. The larvae develop in water and, like other species in tribe Eristalini, have a long breathing tube. The genus has a Holarctic distribution and comprises a total of nineteen species, five of which can be found in Minnesota.