Common Bog Fly

The Common Bog Fly (Parhelophilus laetus) is a medium-sized, orange-colored, Nearctic flower fly. Adults have a pair of stripes on the thorax often with a thin center stripe between them. The hind femur is mostly orange with a black band around the middle. The adults are commonly found perched on grass blades near the shorelines of ponds and wetlands. The larvae have long breathing tubes which allow them to live in low-oxygen waters thick with decaying organic matter.

Flight season:

Flowers: Grass and Sedge

Similar species: Helophilus sp. and Lejops sp.

Dusky Bog Fly

The Dusky Bog Fly (Parhelophilus rex) is a medium-sized, dark-colored, Nearctic flower fly. Adults have a pair of thin gray stripes on the thorax. The hind femur is almost entirely black. The larvae have long breathing tubes which allow them to live in low-oxygen waters thick with decaying organic matter.

Flight season May – July

Flowers: Willow catkins

Similar species: Parhelophilus obsoletus and Helophilus sp.

Parhelophilus rex
Parhelophilus rex – St Louis County – June 2, 2017

Long-nosed Swamp Fly

The Long-nosed Swamp Fly (Eurimyia stipata) is a small, gray, yellow, and black, Holarctic species. Unlike most other Syrphidae, female and male eyes are separated. Males have thinner abdomens and are the more colorful. The larvae have long tails and are found in wet areas with decaying vegetation at the edge of ponds and other wetlands.

The taxonomy of this species is a little messy. In Europe it’s Anasimyia lineatus. Here it has been known as Lejops lineatus or Lejops (Eurimyia) lineatus or Eurimyia lineatus, and currently Eurimyia stipata. The common name, Long-nosed Swamp Fly, simplifies the problem.

Flight season: May – July

Flowers: Sweetflag Iris, Spiderwort, Creeping Thistle

Similar species: Lejops bilinearis and Parhelophilus sp.