Bug FAQNarrow-headed Marsh Fly
Helophilus fasciatus · Order: Diptera · Family: Syrphidae
The narrow-headed marsh fly is a 13 to 15 mm syrphid that lives near water and wet decaying material. Adults visit flowers for nectar and pollen, while larvae drop into water after hatching and develop in decaying vegetation.
Source: Wikipedia
Size
Adults are 13 to 15 mm long (about half an inch).
Source: Wikipedia
Where it lives
The species is found near ponds, mud, farmyard manure, or silage where decaying vegetation accumulates. Adults are commonly seen on flowers.
Source: Wikipedia
What it eats
Larvae hatch and drop into water to feed on decaying organic material.
Source: Wikipedia
Life cycle
Females lay eggs on vegetation overhanging water; the eggs hatch and the larvae fall into the water.
Source: Wikipedia
Where it comes from
It is abundant across the United States and Canada.
Source: Wikipedia
Where it is found in the US
Recorded in 50 of 51 states and DC. Most records: Minnesota, Illinois, New York, Ohio, Wisconsin, Texas, Massachusetts, Michigan.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Status: native in North America; native in Canada; native in United States. Source: iNaturalist
Months it is reported in the US
Source: GBIF
More photos
Same family (Syrphidae)
Sources
- Wikipedia: https://en.wikipedia.org/wiki/Helophilus_fasciatus
Look it up elsewhere: GBIF · iNaturalist · BugGuide · ITIS · Wikipedia
Text written 2026-10-22 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-22.