Traps set in search of rare species in Wales marsh capture something ‘even rarer’
A species believed to have been extinct for nearly a decade was found during a wildlife survey in Wales.
In July and August, researchers set up light traps in Cors Goch Nature Reserve in Anglesey in search of a rare caddisfly species called Limnephilus tauricus, according to a Sept. 17 news release from Natural Resources Wales.
After checking the traps, experts said the team was “delighted to discover” it had caught an “even rarer” caddisfly species — Limnephilus pati.
The species, which requires “very clean, calcium-rich water to survive,” is at risk of habitat degradation and loss due to “agricultural intensification,” experts said.
It is “thought to have been extinct in Britain since 2016,” according to the release.
“Caddisflies survive by being masters of disguise; the brown adults blend into the vegetation, while the larvae live inside cases that they camouflage with stems, sand and seeds,” Clare Sampson, Natur am Byth project manager for the Royal Society for the Protection of Birds, said in the release.
The caddisfly has also been recorded in Market Weston Fen in Suffolk and Eochar, Scotland.
“This incredible discovery shows why consistent surveying is such an important element of conservation work,” Sampson said. “By gathering data on our most at risk species and their habitats we can focus our work where it’s needed most and ensure their survival now and into the future.”
The Natur am Byth in partnership with the Royal Society for the Protection of Birds and North Wales Wildlife Trust conducted the survey to record the caddisfly species living on the Cors Goch wetland habitat, according to the release.
This story was originally published September 18, 2025 at 3:30 PM with the headline "Traps set in search of rare species in Wales marsh capture something ‘even rarer’."
