Dioctria atricapilla
In 3 days ~10% in a week ~20%
Dioctria atricapilla, the violet black-legged robber fly, is a species of robber fly in the subfamily Dasypogoninae. This 9- to 12-millimeter long insect has a wingspan of roughly 7 to 9 mm and short, three-segmented antennae. It's a predatory insect, feeding mainly on smaller flies and predatory hymenopterans. It primarily thrives in grassland, and is seen from May to July.
Like all robber flies, the violet black-legged robber fly feed by perching on lower stems of grasses and attack prey as it flies by. The larvae usually grow up in dung piles or decaying organic matter, but they can also be in regular soil.
Courting behavior involves the male leading the courtship dance in front of the female. If she isn't impressed, she'll rapidly move her wings or fly away; otherwise the male will begin copulating. There are 24 locations in the United Kingdom where it's a protected species, mostly in England. It can be found throughout European and east Palearctic grasslands.
Difficult to distinguish from other Dioctria. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Warsaw | 🇵🇱 Poland | |
| 2 | London | 🇬🇧 United Kingdom | |
| 3 | Birmingham | 🇬🇧 United Kingdom |
Rare
Under 5% of wildlife watchers report a Violet Black-Legged Robber Fly sighting in Birmingham on a given day, based on 7 verified sightings from GBIF citizen-science data. It is the 668th most-seen of the 811 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.
May and June
In those months about 10% of wildlife watchers report a Violet Black-Legged Robber Fly in Birmingham on a given day, against under 5% in July to April, the lowest months.
Between 4 and 7 pm
Across all the parks we cover, that three-hour window holds the most Violet Black-Legged Robber Fly sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
3rd of 3
Of the 3 cities where we can rate Violet Black-Legged Robber Fly sightings, Birmingham ranks 3rd at under 5%. The best odds are in Warsaw (Poland, about 10%) and London (United Kingdom, under 5%).
Same genus: Dioctria
The closest relatives of the Violet Black-Legged Robber Fly that you can see in Birmingham (genus Dioctria) are Stripe-Legged Robber Fly (about 10%) and Common Red-Legged Robberfly (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Violet Black-Legged Robber Fly is recorded against all the insects logged in Birmingham (7 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.
