By Oliver Slow

Copyright bbc

Using light traps, surveyors had been looking for the limnephilus taricus species of caddisfly, but instead found the limnephilus patis, which is even rarer.

The larvae among the species are aquatic, living among dense vegetation in wetlands, while the adults fly from spring until early August.

The habitats where they are found are some of the most diverse in Britain but are at risk from drying out and the impacts of “agricultural intensification”, according to Natural Resources Wales.

The discovery was made in a survey conducted by Natur am Byth, an agency focused on saving threatened species in Wales, as well as RSPB and North Wales Wildlife Trust.

“It was a delight to find it at Cors Goch along with a number of other species that indicate clean water and a rich habitat,” said Clare Sampson, Natur am Byth project manager for RSPB.

“Discoveries like this prove that there are always exciting finds in nature, and they can be found right on your doorstep,” she said, adding that the discovery also shows why consistent surveying is “such an important element of conservation work”.