Rare continental butterfly spotted breeding in town

Continental Swallowtail. SUS-140616-104120001
Continental Swallowtail. SUS-140616-104120001

A beautiful rare butterfly has been spotted emerging from pupae in Eastbourne, fuelling hopes it is attempting to colonise in England.

Unprecedented footage shown on Springwatch last week caught the spectacular continental swallowtails hatching out in gardens and allotments in the town, as well as Hastings and Chichester, for the first time.

Last year’s hot summer led to the largest invasion of this colourful butterfly since 1945 and adults laid a number of eggs in towns along the South coast. Usually, the Mediterranean insect finds it too difficult to survive the cold British winter but the sight of large caterpillars in suburban areas of Eastbourne, followed by footage of adults emerging from pupae suggests the mild winter may have helped them survive, making this the first of potentially dozens of exciting new colonists created by climate change.

There is already a swallowtail subspecies in Britain but it is a smaller, weaker insect than its continental cousin and is only found on the Broads in Norfolk. The continental swallowtail, which is unmistakable with its striking black and yellow markings and steamer-shaped tail, is larger and far more robust, with its caterpillars able to survive on common garden plants including carrots, fennel and hogweed – raising hopes it could soon be seen across the country.

Michael Blencowe, from Butterfly Conservation’s Sussex branch, who has been monitoring the butterflies since they arrived last summer, said, “So far there have been 12 sightings of swallowtails in Sussex this spring. Six of these have been seen to emerge from pupae we were monitoring.

“There are still more to emerge and no doubt many other swallowtails that we don’t know about are roaming the country, so there has never been a more exciting time to head out looking for butterflies.

“This current invasion could be the start of the colonisation of southern England by the swallowtail. In 20 years this butterfly could be a regular visitor to our gardens.”