Tephritis bardanae
In 3 days ~20% in a week ~30%
Tephritis bardanae is a picture-winged fly of the family Tephritidae, which are variously known as fruit-flies (North America) or gall flies (Britain and Ireland). The larvae feed in the flower-heads (capitula) of species of Arctium (burdocks), causing galls to form.
The larvae pupates in autumn, forming a black puparium. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Helsinki | 🇫🇮 Finland | |
| 2 | Stockholm | 🇸🇪 Sweden | |
| 3 | Brussels | 🇧🇪 Belgium | |
| 4 | Rotterdam [The Hague] | 🇳🇱 Netherlands | |
| 5 | Kazan | 🇷🇺 Russia | |
| 6 | Yekaterinburg | 🇷🇺 Russia | |
| 7 | London | 🇬🇧 United Kingdom | |
| 8 | Saint Petersburg | 🇷🇺 Russia | |
| 9 | Moscow | 🇷🇺 Russia |
With luck
About 10% of wildlife watchers report a Burdock Fly sighting in Brussels on a given day, based on 10 verified sightings from GBIF citizen-science data. It is the 181st most-seen of the 337 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 30%, if each day is a fresh chance.
April–August and October
In those months about 10% of wildlife watchers report a Burdock Fly in Brussels on a given day, against under 5% in September and November–March, the lowest months.
Among the best
Of the 9 cities where we can rate Burdock Fly sightings, Brussels ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Helsinki (Finland, about 10%) and Stockholm (Sweden, about 10%).
GBIF citizen-science records
It is estimated from how often the Burdock Fly is recorded against all the insects logged in Brussels (10 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.
