Rare Moth Recorded for the First Time at a Welsh Nature Reserve

Conservationists in Wales have made an unexpected discovery after finding a rare species of moth at a nature reserve where it had never been recorded before.

The Bog Grass Moth was identified at Cors Geirch National Nature Reserve on the Llŷn Peninsula in Gwynedd during a survey of insects living in the area’s wetland habitat.

A Surprising Discovery

The discovery came after conservationists and wildlife specialists set up moth traps overnight as part of a survey of the reserve’s biodiversity.

In total, the traps collected 446 moths representing 91 different species. Among them were 19 Bog Grass Moths, marking the first confirmed record of the species at the site.

A Rare Species

The Bog Grass Moth is considered scarce in Britain and has previously been recorded in only a limited number of areas. Scientists do not currently have an exact estimate of its total UK population.

The moth depends on wetland conditions because its caterpillars feed on wet sedges. These plants grow in the particular conditions found in the reserve’s fen habitat.

Why the Habitat Matters

The discovery provides another indication of the importance of protecting specialist wetlands. Cors Geirch is also home to other uncommon invertebrates, including the Six-spotted Cranefly and Black Night-runner Ground Beetle.

Conservation work at the site aims to maintain the wet and calcium-rich conditions needed by these species and the plants they depend on.

A Small Discovery With a Bigger Message

Experts involved in the survey said the find demonstrates how much there is still to discover through careful monitoring of natural habitats.

The discovery is particularly notable because many peatland and fen habitats in the UK have been lost or damaged. Protecting the remaining areas can provide rare species with places where they can continue to survive.

Sources

• BBC News — “’Special surprise’ as rare moth found in nature reserve for first time,” September 30, 2026.
• Natural Resources Wales — Information on Cors Geirch National Nature Reserve and its wildlife.
• RSPB Cymru — Information on the Natur am Byth conservation project in North Wales.