A rare moth thought to be unique to Glen Affric in Inverness-shire will be the focus of a survey this month – exactly a century to the day since the first recorded sighting of the species in the UK.
First discovered in the glen near Fasnakyle on 12 August 1919, Choreutis diana, known colloquially as the Inverness Twitcher, is a small day-flying moth that has only been seen sporadically over the years.
Tom Prescott, of Butterfly Conservation Scotland, said: “This small but colourful moth has only ever been recorded in the UK in Glen Affric where it is very elusive even as an adult, whilst the caterpillars were only found for the first time in the glen in 2007.
“For a long time it was thought that the moth was confined to a very small area around Forestry and Land Scotland’s top car park in Glen Affic.
“However, earlier this year, the characteristic larval spinnings were found in three or four locations in the glen, as well as at two sites in the adjoining glen beyond Tomich.
“Having such a rare species on our doorstep is very exciting and in this, its ‘anniversary’ year, we want to greatly expand our knowledge of this moth and build up a picture of its current status in Glen Affric - its range, presence and habitat requirements.
“We need the help of volunteers to survey a small number of areas to look for the adult moth– and they don’t have to have any special knowledge of moths to get involved.”
The apparent spread of the moth may be linked to the increase of birch in the area as a result of native woodland regeneration.
Giles Brockman, from the Forestry and Land Scotland team who help look after Glen Affric’s woodlands, said: “As well as helping to maintain the incredible visual beauty of one of Scotland’s most iconic Glens, birch is a really valuable species in terms of boosting biodiversity in a woodland.
“They’re not only good for enriching the soil but they also sustain over 300 species of insect – which in turn serve as a food source for many different birds. News that the ‘Inverness Twitcher’ seems to be so well established in Glen Affric is great news and a testament to the benefits of reintroducing native woodland at appropriate sites.”
Participants in the survey are advised to bring midge repellant.