death's-head hawk moth is a harbinger of pestilence and death.

Death’s-head hawk moth: spotted in England. Photograph: Butterfly Conservation/PA

As the favoured signature of the serial killer in The Silence of the Lambs, the death's-head hawk moth is a harbinger of pestilence and death. But the benign sunshine and warm southerly winds of an Indian summer have brought the rare moth flying to our shores.

The death's-head, a forbiddingly charismatic insect with a distinctive skull pattern on its thorax, has been sighted along the south coast at Arne, Dorset, and in Plymouth, Devon, in what is proving to be a vintage autumn for exotic migratory moths.

Most exciting for Britain's army of amateur moth recorders is the largest influx of the rare flame brocade moth for 130 years, with lepidopteristssuspecting that the purplish-brown moth has established a breeding colony at an undisclosed location in Sussex.

Michael Blencowe, Butterfly Conservation's officer for Sussex, and a friend, Graeme Lyons, first discovered the flame brocade when one turned up in a back garden last weekend.

"I'd never seen one of these moths before so I grabbed my net and went off to find out if there were any others about at a suitable site nearby," said Blencowe. "I saw 10 that night and there have been recordings of 20 or more there every night since."

This has been the best season for migratory moths for more than five years, according to Butterfly Conservation. Other species lured by the Indian summer include the distinctive crimson speckled, the dainty vestalmoth and Spoladea recurvalis, an extremely rare tropical species.

Before 2006 there had been just 19 records of Spoladea recurvalis in Britain, with 19 recorded that year. More than 20 have been recorded so far this autumn in Sussex, Dorset, Cornwall, Cumbria and the Isle of Man, ushered into the country by southerly winds.

Usually only single figures of flame brocades, which is more commonly found in France and Spain, turn up in the UK each autumn. Mark Parsons, head of moth conservation for Butterfly Conservation, said: "This moth appears to have been making an attempt to recolonise these shores, possibly as a result of more favourable overall weather conditions through climate change."

The death's-head hawk moth is the largest moth to fly in Britain and has the ability to fly into beehives in search of honey without being stung. If handled, it can emit a loud squeak, which terrified medieval Europeans. In Poland, where the moth was called the wandering death-bird, its cries were likened to those of a grief-stricken child.

It has been a shorthand for horror ever since: given an honourable mention in Bram Stoker's Dracula, more recently its pupae were left in the mouths of victims by the serial killer in The Silence of the Lambs.