Regional Species


Welsh Clearwing
Synanthedon scoliaeformis

Photograph by Janet Graham (Near Llanuwchllyn)

Photograph by Janet Graham (Near Llanuwchllyn)

Regional Species

A scarce species that was first found in Britain near Llangollen - hence the vernacular name. It now appears to be absent from that area but is still present, at low density, in southern Merionethshire and adjacent areas of Montgomeryshire. (It also occurs in mid Wales and at least two sites in England and in Scotland).

The species is associated with mature birch trees in exposed situations. The larvae actually feed within the bark of these trees and, given the un-nutritious nature of their food, take several years to reach their final instar. They pupate beneath the bark and emerge as adults in June or July. In this process they leave behind their characteristic circular emergence holes, within which it is often possible to find the empty pupal case and cocoon.

There are few suitable trees in North Wales and the number of larvae per tree is usually low, so the total population must be very small. Threats to the species include felling of old trees for agri-environment hedgerow restoration schemes, planting up open woodlands for conservation reasons and simply the lack of any woodland regeneration due to sheep grazing.

Anyone finding circular holes, about 5mm in diameter, in old birch trees (see lower picture) should get in touch with Butterfly Conservation as they may have discovered a new colony of this very special Welsh moth.

Further information available from the NW Lepidoptera Database, including access to detailed records, maps, flight-time charts and photographs.