A rare moth species has been identified in a north Wales nature reserve, with experts describing the finding as a significant ecological discovery. The Bog Grass Moth was located at Cors Geirch National Nature Reserve on the Llŷn Peninsula in Gwynedd during a routine survey of local biodiversity.
Natural Resources Wales described the event as a “special surprise,” noting that the moth is incredibly sparse within its habitat. While the exact UK population remains unknown, the species has previously only been recorded in a limited number of English counties, including Dorset.
The survey was conducted by the Natur am Byth Llŷn and Ynys Môn project, which is dedicated to protecting some of the region’s most endangered species. Over the course of a single night, experts collected 446 moths representing 91 different species from their traps. Among these, 19 were identified as Bog Grass Moths, marking the first time the insect has been documented in this specific area.
The reserve’s fen habitat, characterized by low, flat, wet land, supports wet sedges, which serve as the sole food source for the Bog Grass Moth’s larvae. Sedges belong to one of the world’s largest plant families and thrive in wet environments.
Steve Palin and Charles Aron, lepidopterists specializing in moth study, highlighted the unpredictability of such fieldwork. “You just never know what’s going to turn up,” they stated, adding that the discovery underscores the importance of targeted recordings in specialist fen habitats where much remains to be learned about regional insects.
Clare Sampson, a project manager for RSPB Cymru, credited the efforts of staff, contractors, and volunteers for managing the wetland environment. She noted that despite a hot, dry summer affecting many fens, the site supported healthy numbers of the Black Nightrunner Ground Beetle and the Six Spotted Crane Fly, alongside the rare moth.
Sampson emphasized the broader environmental context, stating that approximately 80% of UK peatlands have been lost or damaged. This degradation threatens species dependent on specific habitats and compromises the carbon-storing capacity of healthy peat, which releases greenhouse gases when damaged.
“These important fen sites can be managed and maintained so that future generations can continue to make new discoveries,” Sampson added.
Eighty percent of UK peatlands gone is terrifying. Glad this reserve is holding on, but we need to protect more sites like Cors Geirch immediately.
Is it really a new discovery, or did previous surveys just miss them? With only 19 spotted, I wonder if they are already there undetected.
This is fantastic news for Welsh biodiversity. It really proves that active wetland management can reverse habitat loss and bring rare species back.