Cannibal spiders munch their way out of extinction

Click to follow
The Independent Online
Things are looking up for the cannibalistic ladybird spider, one of the rarest and most colourful in Britain. Conservationists have made a breakthrough in captive breeding techniques which could secure its survival.

It had been thought that the spider, whose mother makes the ultimate sacrifice of feeding herself to her young, had become extinct in its British haunts on the Isle of Wight, Dorset and Cornwall. But in the 1980s it was discovered living in a single patch of heathland, smaller than a football pitch, in Dorset.

The first priority to safeguard this tiny remnant was to start clearing the pine trees and rhododendrons which were encroaching on its heathland. This worked - the number of adult spiders in the isolated colony soared to about 100.

The next step was to breed the half-inch long ladybird spider in captivity, so that new colonies could be founded elsewhere in the wild from the pool of kept arachnids.

To develop successful techniques for captive breeding, it was necessary to practise on a small number of ladybird spiders taken from Jutland in Denmark. They are fairly rare there, but at last they are not restricted to a single site.

Biologist and arachnophile Pat Wisniewski was thrilled to witness a mating in captivity at his home near Ormskirk, Lancashire where he keeps the Danish imports. And now many of the babies have hatched out, survived their winter hibernation and are growing.

Dr Roger Key of English Nature, the Government's wildlife conservation arm, said the plan was to take some of the English ladybird spiders next year, breed them in captivity then release their young into suitable habitat to found new colonies. "We're really just practising with the Danish ones - we wouldn't release them into the wild here because their genes are likely to be slightly different from the native stock."

The spiders live in burrows and have silk trip wires radiating out to catch insects as large as bumble bees. The male has striking black and vermilion colours and emerges from underground only during the breeding season in May. The female stays in her burrow all of her life after digging it, and she lays up to 80 eggs. Once they hatch her babies eat their mother's regurgitated food and then, as she weakens and dies, they start to consume her.