Horrid Ground-weaver

Fast Facts

Latin name: Nothophantes horridus

Notable feature: The Horrid Ground-weaver is an endemic species and has only ever been found at three sites in the world, all within a small area of Plymouth.

Conservation Status: Critically Endangered

Where in the UK: The Horrid Ground-weaver has only ever been found at three sites in the world, all within a small area of Plymouth in South West England.

Horrid Ground-weaver (Nothophantes horridus) © Tom Thomson (CC BY 2.0)

The Horrid Ground-weaver (Nothophantes horridus), is a native, endemic, money-spider with a body length of about 3mm and may be one of the rarest spiders in the world!

The Horrid Ground-weaver is distinguishable by its very hairy elongate abdomen, usually orange-pink colouration with no distinct markings and the strong spine-like hairs on the legs.  The abdomen can vary in colour, however, between individuals from pale orange-pink to dark brown.

The spider was discovered as new to science in 1989 by R.A Stevens and features in Buglife’s Britain’s Endemic Invertebrates Report (2023)

Because the spiders limited distribution, much is still not known about it and there is a lot to learn!

Size: Adults measure about 3mm in length
Life span: Approximately 1 year
Diet: This is largely unknown but the Horrid Ground-weaver most likely feeds on springtails.
Reproduction: Breeding takes place between December and April when the older generation then dies off.  In captivity, female spiders have been observed constructing egg cocoons each, containing about 20 eggs amongst or under rocks. The spiderlings emerge in the spring.  They grow through the summer months, becoming adults in the autumn, before the cycle begins once again.
When to see:  Peak season for adult spiders seems to be in December and January
Population Trend: Unknown – the Horrid Ground-weaver is classed as Critically Endangered on the IUCN Red List.
Threats: Loss of habitat as a result of development.  Of the three known sites, one was developed and the spider’s habitat destroyed.  A further site has been periodically threatened with development.  In 2017, Buglife worked with Plymouth City Council to re-route and raise a new cycle path at a site in Billacombe to avoid disturbing the spider’s habitat.
Fun Fact: 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.

How you can help:

Buglife is working to increase awareness of invertebrates and the Horrid Ground-weaver through specific projects, such as our Horrid Ground-weaver Species Recovery Project, and campaigns, but we need your help!

Join a recording scheme and log your finds – send any records/sightings to the British Arachnological Society or download the iRecord app and get recording!

Do remember that we rely on donations to continue our work. If you have searched, found and learnt about our incredible invertebrates on our website, please do consider Making a Donation, Becoming a Member or maybe even making a purchase in our shop. For more ideas on how to support our work find out how to Get Involved. Thank you 🕷