Helophilus hybridus
In 3 days ~30% in a week ~50%
Helophilus hybridus is a hoverfly. It is a Palearctic species. For terms see Morphology of Diptera Wing length 8·5-11·25 mm. Femorae 3 top 1/4 or less yellow. Tibiae 3 pale on basal 1/4 or less. Males tergite 2 large yellow spotsreach the hind margin over their full width. The larva is illustrated by Hartley (1961). See references for determination
Palearctic Fennoscandia South to North France. Ireland East through North Europe and Central Europe (including the Alps) East into Russia and on through the Russian Far East and Siberia to the Pacific coast. Mongolia. Nearctic from Alaska to Nova Scotia and South to Utah.
Habitat: wetlands non-eutrophic pools in fen, poor fen, deciduous woodland and dune slacks, cutover valley bog, fen carr, taiga. Flowers visited include white umbellifers, Calluna vulgaris, Cirsium, Convolvulus, Crataegus, Echium, Euphorbia, Limonium, Lycopus, Mentha aquatica, Menyanthes, Narthecium, Parnassia palustris, Plantago, Pulicaria, Rosa, Rubus, Salix repens, Salix, Senecio, Sorbus, Succisa, Taraxacum, Valeriana.
The flight period is early May to early September. External images Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Riding Mountain National Park | 🇨🇦 Canada | |
| 2 | Wadden Sea National Park | 🇩🇪 Germany |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Anchorage | 🇺🇸 United States | |
| 2 | Edmonton | 🇨🇦 Canada | |
| 3 | Warsaw | 🇵🇱 Poland | |
| 4 | Birmingham | 🇬🇧 United Kingdom | |
| 5 | Manchester | 🇬🇧 United Kingdom | |
| 6 | Leeds | 🇬🇧 United Kingdom | |
| 7 | Helsinki | 🇫🇮 Finland | |
| 8 | Yekaterinburg | 🇷🇺 Russia | |
| 9 | London | 🇬🇧 United Kingdom | |
| 10 | Calgary | 🇨🇦 Canada |
With luck
About 10% of wildlife watchers report a Woolly-Tailed Marsh Fly sighting in Anchorage on a given day, based on 14 verified sightings from GBIF citizen-science data. It is the 18th most-seen of the 59 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
In that month about 20% of wildlife watchers report a Woolly-Tailed Marsh Fly in Anchorage on a given day, against under 5% in September to April, the lowest months. That is one of Anchorage's wettest months, with about 110 mm of rain against 40 mm in April.
Between 2 and 5 pm
Across all the parks we cover, that three-hour window holds the most Woolly-Tailed Marsh Fly sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Yes
Of the 12 cities where we can rate Woolly-Tailed Marsh Fly sightings, Anchorage has the highest daily chance: about 10%. Next come Edmonton (Canada, about 10%) and Warsaw (Poland, about 10%).
Same family: Syrphidae
The closest relatives of the Woolly-Tailed Marsh Fly that you can see in Anchorage (family Syrphidae, Hover Flies) are Orange-Spotted Drone Fly (about 10%), Eurasian Drone Fly (about 10%) and Narrow-Banded Pond Fly (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Woolly-Tailed Marsh Fly is recorded against all the insects logged in Anchorage (14 verified sightings), 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.
