Urgent warning for Britons as spiders the size of RATS invade UK in their thousands

Britain’s largest spider, the size of a man’s hand, is growing exponentially in numbers, new research has found.

While it may be frightening to arachnophobes, the Fen Raft Spider’s dramatic increase in numbers is a conservation success story.

The spider, which spins webs the size of a pizza (25cm), was on the brink of extinction in the UK in 2010.

After that, the spider was restricted to just three locations in the UK: Suffolk and Sussex, leaving only a handful of spiders.

Thanks to a successful breeding campaign there are now 3,750 breeding females at 12 sites in Norfolk alone.

While it may be scary to arachnophobes, the Fen Raft Spider’s massive growth in numbers is a conservation success story

It is thought that efforts to improve the animals’ habitat and this year’s wet weather have given the species a boost.

Tim Strudwick, manager of the RSPB Mid Yare nature reserve, said he was proud the spider had been recovered.

He said: ‘The Fen Raft Spider is one of the rarest invertebrates in the UK and we are proud of the role our reserves and teams have played in its recovery.

‘These spiders play an important role in preserving the rich water diversity in the grazing ditches in our reserves.

‘The females are impressively large, but also beautiful – it’s really special to see them.’

The marsh spiders have striking white or cream-colored stripes running down the sides of their abdomen.

The spider lives half in water and can run across the water surface to catch prey.

The spider, which spins webs the size of pizzas (25cm), was on the brink of extinction in the UK in 2010

Their diet includes spiders, damselflies, dragonfly larvae and water skaters. They even catch fish and tadpoles.

Although the species is still vulnerable and has been designated as a priority species, the annual spider surveys take place in September in these reserves. We hope that this will be another successful breeding year.

He added that the spiders can also be seen at another RSPB site in Norfolk, Strumpshaw Fen. ‘The spiders are only seen in the ditches of the grassland fen and are quite shy, but from June to September they are easier to see.’

‘If you walk along the meadow path, you have the best chance of seeing adult females and their shiny nursery webs at Strumpshaw Fen, so this is the perfect time to take a trip to the reserve.’

RSPB ecologist Jane Sears, who has been involved in the conservation of the Fen Raft Spider, said: ‘The RSPB has played a major role in the reintroduction of these spiders, so we must continue to restore, manage and protect the wetlands where the Fen Raft Spider thrives. This will not only secure the future of this species, but many others too.’