Horrid Ground-weaver Project

The Horrid Ground-weaver is a tiny money spider with a body length of about 3mm. It is endemic to the UK, and until this project, had only ever been found in three places in the entire world, all within a small area of Plymouth, in South West England. It is listed by the IUCN as a Critically Endangered species. The spider’s name comes from the fact that its body and legs are rather hairy – the Latin origin for the word horrid is bristly.

The spider was discovered as new to science in 1989 by R.A Stevens.

One of the three known sites has already been lost to development, and another has been regularly threatened. All sites are either in or close to limestone quarries where spiders have been found underneath rocks and amongst leaf litter. Because the spider is known from so few sites, much is still not known about it.

What did the project do?

In 2015 Buglife orchestrated a successful campaign to save one of the Horrid Ground-weaver sites from development.

The Crowdfunding effort that ran alongside the campaign, along with funding from the Mohammed Bin Zayed Species Conservation Fund helped us to learn more about the ecology of the spider, and also to discover the third site.

In 2017, Buglife also worked with Plymouth City Council to reroute and raise a new cycle path to avoid disturbing any of the spider’s habitat at a site in Billacombe.

Then, between summer 2023 and March 2025, Buglife looked to expand our knowledge of this rare and wonderful creature by undertaking further surveys, trialling new methods and searching new sites. A new location for the spider was found in 2023, after surveying 13 sites in Plymouth and a further four in suitable South Devon limestone quarries.

We have been working closely with Plymouth City Council to provide habitat management advice and support scrub clearance work on their sites. This has resulted in the spider being found in a recently cleared area, where it hasn’t been recorded for the last four years due to scrub encroachment.

Can I still support the Horrid Ground-weaver?

For now, take a look at this amazing video of the Horrid Ground-weaver, filmed by John Walters.

More information about money spiders can be found on the British Arachnological Society website