Helophilus lapponicus
In 3 days ~30% in a week ~50%
Helophilus lapponicus, the Yellow-margined Marsh Fly, is a common species of syrphid fly observed across northern North America, northern Europe, Greenland and Siberia. Hoverflies can remain nearly motionless in flight. The adults are also known as flower flies for they are commonly found on flowers, from which they get both energy-giving nectar and protein-rich pollen. Though common the larvae of this species are not known but the larvae of other species in this genus are associated with wet decaying organic material, particularly accumulations of decaying vegetation in ponds and mud and are a so called rat-tailed type.
For terminology Speight key to genera and glossary 12.5–13.5 mm (0.49–0.53 in) The face is deeply concave below the antennae, with a strongly produced tubercle that is large and recedes in profile. The lower border of the face forms an obtuse angle with the posterior border of the head. In the middle of the face is a broad, shining grey dusted black stripe that reaches to the base of the antenna. The face is covered with whitish-yellow or grayish-yellow pollen, except for the gena which are shining black. The pile of the frons... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Pacific Rim National Park Reserve | 🇨🇦 Canada |
More parks will be added in future updates.
With luck
About 10% of wildlife watchers report a Yellow-Margined Marsh Fly sighting in Pacific Rim National Park Reserve on a given day, based on 15 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 50th most-seen of the 107 insects we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
August and September
In those months about 20% of wildlife watchers report a Yellow-Margined Marsh Fly in Pacific Rim National Park Reserve on a given day, against under 5% in October to April, the lowest months. Those are among Pacific Rim National Park Reserve's driest months, with about 120 mm of rain a month against 470 mm in November.
Between 11 am and 2 pm
Across all the parks we cover, that three-hour window holds the most Yellow-Margined Marsh Fly sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Only Pacific Rim National Park Reserve, in our data
Pacific Rim National Park Reserve is the only park on Wallace's Line with enough records to rate Yellow-Margined Marsh Fly sightings: about 10% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Yellow-Margined Marsh Fly is recorded against all the insects logged in Pacific Rim National Park Reserve (15 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
