Scientists have recorded a critically endangered wolf spider, Aulonia albimana, in the UK for the first time in four decades. The arachnid was located within the National Trust's Newtown National Nature Reserve on the Isle of Wight, having not been seen in Britain since 1985.
The tiny spider, notable for its dark brown body and orange legs, has been informally dubbed the white-knuckled wolf spider by the team that found it.
Mark Teller, an entomologist involved in the discovery, said: "To find a species thought lost for 40 years is thrilling - and testament to how the right habitat management, combined with curiosity and collaboration, can deliver remarkable results."
The spiders were discovered in a remote, overgrown section of the reserve that is reachable only by boat. The site is roughly 2km (1.2 miles) from where the species was previously known to occur.
Graeme Lyons, who searched the site with Mr Teller, described the search as a long shot and recalled a dramatic finish:
"I suggested calling it the white-knuckled wolf spider because this was probably the longest long shot I've ever taken part in.
"We had just four hours at the site where this spider was last seen 40 years ago, before our boat came to pick us up.
"I found the first one with just nine minutes to go, and the second one in the last minute.
"I've seen 559 species of spider in the British Isles and this one was by far the most exciting find."
Aulonia albimana is a small species of wolf spider. Wolf spiders are ground hunters that chase and pounce on prey rather than building webs to capture it. There are about 38 species of wolf spiders recorded in the UK.
The team noted distinctive pale markings on the small, leg-like appendages beside the spider's mouth, which partly inspired the informal name.
The nature reserve called the discovery a "major conservation success". The find offers hope that targeted habitat management can support species thought to be lost.
Dr Helen Smith, conservation officer for the British Arachnological Society, said: "The remarkable discovery of this dapper little spider on the Isle of Wight is one of Britain's epic 'lost species' rediscoveries of the century.
"With repeated failure to find it at its former sites, where its open habitat has been lost, it seemed increasingly likely that it had joined the country's sad list of extinct species."
The rediscovery highlights how careful site management, expertise and persistence can reveal species that have gone unrecorded for decades. It also underscores the fragility of habitats that certain specialist species depend on and the importance of ongoing conservation effort.