Regional Species


Ashworth's Rustic
Xestia ashworthii

Photograph by Janet Graham (Near Llanuwchllyn)

Regional Species

There are two British moths found only in North Wales. This is one of them and the Weaver's Wave is the other. Thus, for the last 150 years, since its discovery by Mr Ashworth of Llangollen, lepidopterists have been making the journey to our region with the specific aim of seeing this nationally scarce moth.

In fact, it does seem to be a common moth in the hills of northwest Wales and perhaps the biggest unanswered question is why its range in Britain is so restricted. The moth comes readily to light and has been recorded from early June to the end of August, with peak numbers in mid-July. The habitat requirement appears to be for areas with exposed rock such as crags, scree slopes or even quarries. The type of rock seems to be irrelevant and is definitely not restricted to slate and limestone as is frequently stated in the literature. The larvae are reasonably conspicuous and well worth search for in the spring. They are polyphagous and have been observed feeding on various plants including heather, bell heather, bilberry and heath bedstraw. Evidently the species is highly mobile as it is quite common for individuals (usually males) to turn up well away from the usual habitat.

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