#31 Dark Bordered Beauty by Peter Mayhew
Meet Peter Mayhew, Senior Lecturer in Ecology at the University of York!
Peter is a Senior Lecturer in Ecology at the University of York where he has worked since 1998. His research interests include the ecology and evolution of insects; about which he has been involved in a broad spectrum of projects. You can read more about his work here. From 1998 to 2018 he taught on an annual field course in Dalby Forest, sparking an interest in the natural history of Yorkshire which continues to this day. He enjoys walking and recording wildlife, particularly Lepidoptera and plants, and has been part of the team monitoring the Dark Bordered Beauty moth in Yorkshire since 2013. Peter can be contacted at peter.mayhew@york.ac.uk by email, on Twitter @MayhewPeter, and on LinkedIn.
Peter’s chosen species is the Dark Bordered Beauty moth Epione vespertaria. The Dark Bordered Beauty is a small but beautiful geometrid moth, about 2.5cm in wingspan, which flies from June to August in the UK. It has a wide distribution across Europe and Asia but since it was first discovered in Britain has always been considered a rarity; it is currently listed as Endangered here. It is now known only from one site in England (Strensall Common, a lowland heath near York) and a small handful of sites in the Speyside and Deeside areas of Scotland where it inhabits woodland edges and clearings. The caterpillar foodplant is Creeping Willow Salix repens, in England, but in the Scottish sites it is Aspen Populus tremula, suckers. The adults are sexually dimorphic, with the female having a yellower base colour than the male, and it spends most of the year as an egg on or near the larval foodplant. The caterpillars hatch in late spring and grow quickly, pupating in June, the adults emerging in midsummer. The males can be active in the day, especially after sunrise on warm mornings, and fly low over the vegetation in search of resting females to mate. You can find out more about the Dark Bordered Beauty on the NBN Atlas and on the Yorkshire Moths website.
Male Dark Bordered Beauty moth.
This special moth is one of the most important members of the Yorkshire Lepidoptera fauna. The York population in and around Strensall (once extending to the south and east of the current SSSI at ‘Rawdon’s Common’, ‘Sandburn’ and ‘Stockton Common’), was the site of the earliest known records, collected by geologist John Phillips and botanist Henry Baines in July 1827. To this day it remains the most reliable and accessible place to find it. Collectors from all over the country (including such ‘celebrity’ entomologists as Charles de Worms and Francis Orpen Morris) came to find specimens. Others obtained them through exchange with local collectors and breeders, the species becoming a form of entomological currency. This explains how widely the species may be found in museum collections across the country. A beautiful dark variety was sometimes bred or captured at York, known as ab. fulva. There is therefore a rich social history surrounding the species and the people who sought it, extending for nearly 200 years.
Originally Dark Bordered Beauty was probably widespread in Britain where Creeping Willow was found: there are putative records from all five Yorkshire vice-counties, Lancashire and Cumbria, and particularly from Northumberland where a population existed until 2000 at Newham Bog, and before that from other sites in the county. Populations definitely existed in the south of England in the New Forest, and possibly in the Fens and Broads of East Anglia. A few museum specimens are labelled from North Wales and Kent. In Scotland there are also records from the Borders near Hawick and from Sutherland. It is not impossible that undiscovered populations remain in Scotland and the North of England. Creeping Willow, the English foodplant, does not do well in ‘improved’ habitats and the species is now listed as Vulnerable.
The York population of Dark Bordered Beauty has gradually contracted in range over the years. Originally ‘Sandburn’, an outlying fragment of heath along the Malton Road, was the favoured site, but this gradually became overgrown and there have been no records from that site since the 1950s. It is unlikely that the foodplant exists there now. ‘Rawdon’s Common’ is now a municipal tip and a conifer plantation, whilst the fields around Stockton Common have been ‘improved’ and are no longer suitable habitat. It appears that the species was introduced to Askham Bog, to the south of York, in the last decade of the nineteenth century, but Creeping Willow is now extinct at the site and there have been no twentieth century records. The moth is therefore now confined to the Strensall Common SSSI.
Female Dark Bordered Beauty moth, at Strensall Common.
Peter first got involved with the conservation of Dark Bordered Beauty in 2013, when he was looking for an excuse to spend more time outdoors; ‘Administrative work was increasingly chaining me to my desk along with a vast number of board-room ‘meetings’. One of the original transect walkers was retiring, and a call went out for new volunteers: it seemed like just the thing. The monitoring season takes place after my teaching has finished in the summer term, and Strensall Common in July is a beautiful place to be; spending time in a special place with a special species is a wonderful way to recover from the stresses of the academic year. Watching a number of male Dark Bordered Beauty moths flying low over the heather on an early July morning is an exciting and unique experience. Over the years I have supervised a number of students doing project work connected with the moth and the more I have learned about it, particularly the history of the York population, the more fascinating I find it. Here in microcosm is a story about what the natural world means to people: the value of beauty, the fascination with rarity, the need to be outdoors in nature, the love that people feel for species and places, and the need to protect what they love. It is a story that deserves to continue for another 200 years.’
Monitoring
In 1999 a species action plan was produced for Dark Bordered Beauty in the follow-up to the Rio Earth Summit. As part of this, in 2007 a monitoring scheme was set up in the form of a transect walk, walked by volunteers, on the northern part of the Strensall SSSI where there is open access. The first few years of this showed a large and healthy moth population around the transect route, but in 2010 there was a strong decline from which the population has never fully recovered. The most immediate and obvious cause of this was a fire which destroyed one of the largest areas of Creeping Willow, but subsequent experiments with grazing exclosures has shown that sheep grazing, one of the standard heathland management tools, can hinder the growth of Creeping Willows and is another likely cause of the decline. Short term recovery was found after grazing exclosures were initially established around Creeping Willows, but in 2019 there was another, as yet unexplained decline. In recent years the population has remained very low.
Further information and acknowledgements
NEYEDC would like to thank Peter for his time and expertise in helping to create this blog.