The Long-tailed Blue is an exotic migrant from the Mediterranean with a handful typically reaching UK shores each year, but experts believe climate change is behind this butterfly reaching our shores more regularly and in vastly increased numbers.

One of the largest migrations took place in 2015 when 60 adult butterflies crossed the Channel in August and laid 1000s of eggs in gardens and allotments along the South Coast.

A large, strong-flying butterfly restricted to the Norfolk Broads, although migrants are occasionally seen elsewhere. Pale yellow wings with black veins and blue margins.

This is one of our rarest and most spectacular butterflies. The British race britannicus is a specialist of wet fenland and is currently restricted to the Norfolk Broads. Here the adults can be seen flying powerfully over open fen vegetation, stopping to feed on flowers such as thistles and Ragged-Robin.

The adults come to light, but do not feed. 

They overwinter as shiny black/brown pupae, below or near the larval foodplant. The caterpillars can be seen from June to September and resemble the Poplar Hawk-moth caterpillar, apart from the bluish-coloured spike at the rear.

Size and Family

  • Family - Hawk-moths (Sphingidae)
  • Large Sized
  • Wingspan Range - 70-80mm

Conservation Status

  • UK BAP: Not listed
  • Common

Caterpillar Food Plants

Medium-sized, black and silver-grey moth with a white, usually broken y-shaped mark on the forewing. Lives on moorland. Often found near heather and bilberry.

If disturbed the moth displays its orange hindwings with blue-black spots and can produce a clear yellow fluid from two ducts just behind the head.

The larvae can be seen from August to late the following June. The larvae are hairy and known as the "Woolly Bear". They sometimes feed and bask in sunshine and may be seen moving rapidly across bare ground when fully grown. They pupate in a thin cocoon among vegetation on or near the ground.

The blue or blue-grey border on the outer edge of the forewing is what gives this species its name.  The darker northern form of this moth usually has a complete band of brown across the grey forewings whereas the southern form has lighter forewings with distinct brown blotches. Flies in late afternoon, early evening and after dark.

The larvae can be seen from April to early June. They overwinter as eggs in a fork of a twig on the foodplant.

This beautiful species of butterfly is one of the most characteristic of unimproved southern chalk downland, where it can be seen flying low over shortly grazed turf (typically steep, south-facing slopes).

The males have brilliant sky-blue wings, while the females are chocolate brown and far less conspicuous. Both sexes have distinctive black lines that enter or cross the white fringes of the wings.

A small, widespread butterfly that occasionally visits gardens. Females similar to Brown Argus, which lack blue dusting near body, and to female Adonis Blue, which have dark veins extending into white fringe on wing edges. The male Chalk Hill Blue is paler and, apart from the Large Blue, larger than other blue butterflies seen in Britain and Ireland.

The Common Blue is the most widespread blue butterfly in Britain and Ireland and is found in a variety of grassy habitats.

The brightly coloured males are conspicuous but females are more secretive. The colour of the upperwings of females varies from almost completely brown in southern England to predominantly blue in western Ireland and Scotland, but the colour is variable within local populations with some striking examples. Unlike Adonis and Chalkhill Blues, the dark veins do not extend into white fringes of wing margins.

Similar to upland forms of the Common Heath, but that species has central cross-lines which almost meet and the male has more feathery antennae.  May also be confused with the Latticed Heath, but this moth has stronger and more defined markings with dark.

Overwinters as a pupa, the larva feeding from late May to July. Young larvae feed only on the young shoots

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