Bug Wiki
Sticker of Violet black-legged robber fly
Bug card No. 4591 of 4,939

Violet black-legged robber fly

Dioctria atricapilla

The violet black-legged robber fly is a slim fly, about 1 centimetre long, that hunts other insects. It has short feelers and black legs. You can spot it in grassy meadows from May to July.

Lives in
Grasslands across Europe and into eastern Asia
Length
0.9 to 1.2 cm (0.35 to 0.47 in)
Top speed
about 9.8 km/h (6.1 mph)
Flying, estimate
Can it hurt you?
Harmless
It hunts little insects, not people. Just watch it and let it be.
What does it eat?
It catches other insects in the air, mostly smaller flies and even hunting wasps.
For real!Photo of Violet black-legged robber fly
Picture by Richard Bartz , Munich aka Makro Freak. CC BY-SA 2.5, via Wikimedia Commons.

How big is it?

How long is it?

Violet black-legged robber fly about 1.2 cm long (0.47 in)A grain of rice about 6 mm (0.24 in)A toy building brick about 3.2 cm (1.3 in)
as long as 2 grains of rice in a rowcould fly across a whole football pitch in 39 secondsmoves 230 times its own body length every second

How big is Violet black-legged robber fly compared to YOU?

Just maths in your browser. Nothing is saved or sent anywhere.

How fast is it?

cool stuff

Fun facts

1

It sits on low grass stems and waits. When an insect flies past, it zooms out to grab it.

2

Its young grow up in dung piles, in rotting plant bits or in the soil.

3

The male does a little dance in front of the female. If she does not like it, she flutters her wings fast or flies away.

4

In the United Kingdom it is protected in 24 places, most of them in England.

5

It is very hard to tell apart from its close cousins, so experts use special books to name it.

you asked

Most asked questions about Violet black-legged robber fly

?How big is the violet black-legged robber fly?

It is about 9 to 12 millimetres long, around 1 centimetre.

?What does a robber fly eat?

Other insects, mostly smaller flies and wasps that it catches in the air.

?Is the violet black-legged robber fly dangerous?

No need to worry. It hunts little insects, not people.

For bug experts

Scientific name
Dioctria atricapilla
Group
Flies and mosquitoes
Family
Asilidae
Classification
Insecta > Diptera > Asilidae
Lives on
Europe, Asia

Where the facts come from

  1. Dioctria atricapilla (Wikipedia, CC BY-SA 4.0): what it looks like, where it lives, what it eats, sizes and fun facts, retold in simple words.
  2. Picture by Richard Bartz , Munich aka Makro Freak. CC BY-SA 2.5, Wikimedia Commons. The sticker of this bug is drawn from this picture.

If we got something wrong, sorry, we are bug fans, not a science journal. Tell us at [email protected] and we will fix it.

Bug Wiki honey jar For grown-ups: Bug Wiki is free, with no ads and no tracking. A small tip helps keep it online.Leave a tip

More from the same group: Flies and mosquitoes

Also at home here: Gardens and meadows

Honey jarfor grown-ups