Bug card No. 0824 of 1,500

Large blue

Phengaris arion

Eats: Nectar and pollen ButterfliesGardens and meadows6 legs

The large blue is a pretty butterfly with shiny blue wings sprinkled with black dots. Its caterpillar has an amazing trick. It gets carried into a red ants' nest and lives there with the ants until it turns into a butterfly.

Lives in

Europe and parts of Asia, as far as Siberia and China, in sunny pastures

Wingspan

5.1 cm (2 in)

up to

Top speed

about 14 km/h (8.7 mph)

Flying, estimate

Can it hurt you?

Harmless

Harmless. It cannot bite or sting. It is rare, so enjoy it from a distance.

What does it eat?

The caterpillar first eats thyme flowers. Then it moves into an ants' nest, where the ants feed it.

Photo of Large blue — Picture by PJC&Co. CC BY-SA 3.0, via Wikimedia Commons.

How big is it?

How wide are its wings?

wings as wide as 1.5 toy building brickscould fly across a whole football pitch in 27 seconds

How big is Large blue compared to YOU?

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

How fast is it?

A person walking about 5 km/h (3.1 mph)

A kid running fast about 13 km/h (8.1 mph)

Large blue about 14 km/h (8.7 mph)

A grown-up on a bike about 25 km/h (16 mph)

cool stuff

Fun facts

It can only live where there is wild thyme and one special kind of red ant. Without both, it disappears.

In 1979 it died out in Britain. People brought it back, and now it flies there again.

The caterpillar stays a caterpillar for up to 9 months, much of that time inside the ants' nest.

It is one of the biggest butterflies in its family, the gossamer-winged butterflies.

A grown-up butterfly lives for only a few weeks. It flies from the end of June into August.

you asked

Most asked questions about Large blue

?Where does the large blue butterfly live?

In Europe and parts of Asia, in sunny pastures with wild thyme and red ants.

?Why does the large blue live with ants?

Its caterpillar gets taken into a red ants' nest and lives there until it is ready to become a butterfly.

?How big is the large blue?

Its wings can measure up to about 5 centimetres from tip to tip.

For bug experts

Scientific name: Phengaris arion
Named by: Linnaeus, 1758
Group: Butterflies
Family: Lycaenidae
Classification: Insecta > Lepidoptera > Lycaenidae
Lives on: Europe, Asia

Where the facts come from

Large blue (Wikipedia, CC BY-SA 4.0): what it looks like, where it lives, what it eats, sizes and fun facts, retold in simple words.
Picture by PJC&Co. CC BY-SA 3.0, Wikimedia Commons. The round sticker of this bug is cut from the same 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.