It is a spider that looks like a ladybird when it is in the mood for love, but it is also a pocket-sized killer whose predator skills could be straight from a horror film.

Dubbed Britain's most elusive spider, it lives a subterranean existence, waiting for hapless bugs to come too close to its burrow door when it pounces and drags them underground to have for lunch.

Now this rare creature appears to have been brought back from the brink of extinction thanks to the effort of a small band of conservationists.

The ladybird spider, so named because the males get red and black markings on their backs during the mating season, numbered fewer than 60 when they were counted on their last remaining habitat in Dorset 15 years ago.

But thanks to the combined efforts of the army, the Forestry Commission, Natural England and conservationists from the likes of Dudley Zoo, the Herpetological Conservation Trust and the British Arachnological Society, there are now more than 1,000 of the rare little creatures thriving in the Dorset heath.

The group which got together in the mid-1990s determined to save Britain's then-rarest spider embarked on a programme of managing the heathland, clearing scrub and capturing them to breed and releasing back into the wild.

And in doing so, experts discovered a whole lot more about the ladybird spider than they knew before. They found that the small spider spends most of its life underground, living a solitary existence in a silk- lined burrow with a web over the entrance.

Though small, they are ferocious predators, going after bugs much bigger than them. They will attack a range of large beetles, bees and wasps and drag them underground, but they can also leave the burrow and give chase if their victims won't come to their door.

The captive breeding programme involved releasing the spiders on to a special bit of heathland which is managed to be a perfect haven for the eight-legged ladybird lookalikes.

Dr Helen Phillips, the chief executive of Natural England, said: "Heathland habitats have become increasingly fragmented and degraded in recent decades, placing the fate of many of our species in the balance.

"There is nothing inevitable about this and no reason why we should simply accept biodiversity loss as an unfortunate price of 21st-century life.

"The success of the ladybird spider recovery programme shows what can be done and we are delighted at the very hopeful signs that England's most elusive spider is on the road to recovery."

Natural England said much of the nation's heathland had suffered over the past 100 years from development of towns and conversions to conifer forest or agricultural land.

In Dorset, the heaths have declined but enough remain to preserve and now expand.

But the remaining heathland has become fragmented and in many areas ceased to be managed, leading to the growth of scrub which threatens species such as sand lizards, nightjars and stone curlews.