Bibio xanthopus
In 3 days ~10% in a week ~20%
Bibio xanthopus, or yellow-footed March fly, is a species of March fly (Bibionidae) first identified by Wiedemann in 1828. It is one of the most common species of Bibio in North America. The body is black with pale colored pile and legs that are predominantly rufous. Females have black wings. The size of the species varies considerably, with wingspans ranging from 5.5 to 9.5 mm and body lengths ranging from 8 to 11 mm. The maggots, which feed on roots, are 10 mm in length with warty skin and a pair of posterior spiracles. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Seattle | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Yellow-Footed March Fly sighting in Seattle on a given day, based on 6 verified sightings from GBIF citizen-science data. It is the 354th most-seen of the 428 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
April
In that month about 10% of wildlife watchers report a Yellow-Footed March Fly in Seattle on a given day, against under 5% in May to March, the lowest months.
Only Seattle, in our data
Seattle is the only city on Wallace's Line with enough records to rate Yellow-Footed March Fly sightings: under 5% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Yellow-Footed March Fly is recorded against all the insects logged in Seattle (6 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.
