The red admiral butterfly: identification, origin and peak period

The red admiral (Vanessa atalanta) is one of the most striking of all British butterflies and, though it isn’t immediately obvious, its beauty is reflected in its name; the meaning of its name 'red admiral' being a corruption of the original 18th-century name 'red admirable'.

The combination of its black velvety wings, contrasting with stunning orange lines and white spots makes it one of our most easily identified species.

To call red admirals British is probably a slight misinterpretation since most individuals will have come from the continent. This is a strong migrant species which, every year, returns to us from the Mediterranean region.

The first to reach us arrive in March and they seek out nettles on which to lay eggs. During the summer the eggs hatch and the caterpillars develop so that by August we should have our own crop of adult red admirals.

Their numbers are continually boosted by further migrants from across the English Channel so that by September they are at their most numerous and can be found across the entire length and breadth of the British Isles.

Attracting red admiral butterflies

It is during September that they are most frequently seen in gardens because this is where most nectar can be found at this time of year. Outside of gardens they can often be found drinking nectar from the flowers of ivy, one of the latest abundant flowering species in the countryside. They also like to find rotting fruit so try putting out a tray of rotten apples, plums or blackberries in a sheltered sunny spot in your garden if you would like to give them a treat.

Garden flowers red admirals feed on include hebes, buddleia, heather, sedums and bramble.

Red admiral butterfly life cycle

Egg laying time

The red admirals who migrate in May and June lay their eggs singly on a foodplant, usually nettles. Eggs are light green and darken with age.

Red admiral butterfly caterpillars

Eggs hatch after about a week and the caterpillar makes a protective tent out of leaves, making it easy to spot in the nettle patch if you know what you're looking for. As the larva grows it'll build newer, bigger tents. Caterpillars are dark and spiked, with cream or yellow markings along its side. Red admirals will live as a caterpillar for up to four weeks.

Red admiral chrysalis

Red admirals pupate wrapped in leaves strung together with silk, and will stay like this for up to four weeks.

Transformation into butterflies

After three to four weeks as a pupa the red admirals emerge. They are large butterflies with a wingspan measuring about 7cm. Because red admirals continue to migrate throughout spring and summer they are at their peak in late summer/September.

Male and female red admirals

Male and female red admirals look the same.

Red admiral butterfly and hibernation 

Though some individuals attempt to hibernate in Britain, generally our winters are too harsh for red admirals so they must migrate southwards if they are to survive.

Red admiral butterfly lifespan

Red admirals can live for up to 10 months, but because they do not usually survive British winters it is likely to be shorter.

Find out more about British garden wildlife, including butterfly photography tips and tips for building a wildlife-friendly garden

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