Not found in the UK.

Size and Family

  • Family: Swallowtails
  • Size: Large
  • Wing Span Range (male to female): 70-90mm

Conservation Status

  • Butterfly Conservation priority: N/A                 
  • European Status: Vulnerable

Caterpillar Foodplants

Caterpillars feed on stonecrop (Sedum species)


Diverse - rocky and stony places and vineyards in hills and mountains.

The Rosy Underwing is superficially similar to the native Red Underwing but is slightly smaller and paler looking. Comes to sugar and sometimes to light.

No evidence of breeding in the British Isles but in Europe, the caterpillars can be found between May and June.

There are less than two dozen records from the UK with the first from Shoreham, Sussex in 1875. First recorded on the Channel Islands in 2002 where it is now thought to be resident.

Flight Season

Flies from July to September in one generation, immigrants to the UK can be seen from August.

An unmistakable species that is both common and widespread in Europe but unfortunately only a sporadic migrant to the British Isles with less than 200 records in the last century.

The moth occurs naturally in the Mediterranean and North Africa, and most immigrants are presumed to have originated there, typically arriving with plumes of warm air during the summer or autumn. Attracted to light but also flies during the day when it is easily disturbed.

Like the other tiger moths, this is a large colourful moth with bold markings. Its distinctive features are its black forewings with cream spots, yellow hindwings and a furry black thorax.

When disturbed it will display its hindwings and its orange/red abdomen to warn off predators.

It spends most of the year as a larva, from July to late April or early May, before pupating in a cocoon amongst low vegetation. The adult moth then emerges after about 20 days.

The adults are occasionally seen resting on tree trunks in the early morning. The caterpillars feed inside the trunk of the tree from August to the following May, overwintering as part-grown larvae.

This moth can be distinguished from the Large Red-belted and Red-tipped Clearwings by the absence of any red markings on the forewings.

The adults are occasionally seen flying around apple trees in the afternoon. The caterpillars can be found feeding underneath the bark of the foodplant from August to the following May, overwintering as larvae.

The adult females can occasionally be seen laying their eggs on freshly-cut birch tree stumps. The caterpillars feed inside the tree stump or trunk from July to the following May, overwintering as larvae inside a cocoon.

The grey forewings are crossed by jagged cross-lines and bands. The red hindwing which gives it the English name has a black band around the scalloped margin, fringed with white. Another irregular black band runs across the centre of the red patch of the hindwing.

The larvae can be found from May to July feeding at night and hiding under loose bark or in a crevice during the day. They overwinter as eggs.

Very similar to red forms of the Dark-barred Twin-spot Carpet, although the Red Twin-spot Carpet tends to have brighter markings, with a clearer whiter band bordering the central red band and has a more banded appearance.

Rests during the day on shaded rocks, stone walls, bushes, hedges and tree trunks from which it is easily disturbed. Flies from dusk and into the night.

The rarest of the four British Cosmia species, the White-spotted Pinion underwent a rapid decline as a result of Dutch elm disease during the 1970s and is now scarcely distributed in parts of southern England.

Overwinters as an egg, probably on the foodplant. The green caterpillars have pale stripes and feed from April to mid-June and are said to be more frequent on epicormic growth. Pupates in a cocoon between spun leaves or on the bark.

The male moths will come readily to light, arriving from about 10:30 pm onwards but females are less frequently seen.

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