Helophilus

Key to species

1. Orange median stripe on face … 2
1’. Black median stripe on face … 3

2. Males—the space between the eyes is narrow, less than the width of the antennal pits; Females—the space between the ocelli and the antennae is black pilose … Helophilus faciatus
2’. Males—the space between the eyes is wider than the width of the antennal pits; Females—the space between the ocelli and the antennae is yellow pilose … Helophilus latifrons

3. Thoracic stripes reduced … 4
3’. Thoracic stripes broad … Helophilus hybridus

4. Wide yellow marks on abdomen section 3 … Helophilus obscurus
4’. Narrow yellow marks on abdomen section 3 … Helophilus lapponicus

Narrow-headed Marsh Fly (Helophilus fasciatus) – Goodhue County – April 29, 2013
  • Helophilus (Helophilus) fasciatus Walker 1849 – Narrow-headed Marsh Fly
  • Helophilus (Helophilus) hybridus Loew 1846 – Wooly-tailed Marsh Fly
  • Helophilus (Helophilus) lapponicus Wahlberg 1844 * – Yellow-margined Marsh Fly
  • Helophilus (Helophilus) latifrons Loew 1863 – Broad-headed Marsh Fly
  • Helophilus (Helophilus) obscurus Loew 1863 – Obscure Marsh Fly