Mothy Mutterings – March 2015

This is the third year that we have undertaken monitoring of Richardson’s Case-bearer Eudarcia richardsoni on Portland, Dorset. In Britain, this extremely restricted species is only found around the coast of Portland and at one site near Swanage, Dorset. It was thought to be endemic, but has recently been found in two countries on the continent. We started monitoring this species in 2013 as part of a much larger project (Portland Living Landscapes, a partnership project led by Dorset Wildlife Trust) to remove invading Cotoneaster over the island. The ’s preferred habitat is limestone scree, and in some areas of Portland this was being encroached by invading Cotoneaster. We selected eight subsites, six on the eastern coast and two on the western coast. Timed searches for larval cases were undertaken, this involved turning over rocks on the scree. The total number of cases found during this year’s monitoring was slightly up on the previous two years with 18 found, the cases being found at all subsites. Dead Cotoneaster was evident on several of the subsites. The results have been forwarded to a range of interested partners.

At the very end of last month we undertook a training event on Coleophora hydrolapathella (a Section 41 species with few recent known sites) specifically targeting site managers/conservation workers from various Broadland sites. Tony Davis led this field based workshop with representatives from Norfolk Wildlife Trust, RSPB, National Trust and smaller landowners attending. The aim of this event was to raise the profile of this species, demonstrate how to find the larval cases of C. hydrolapathella and to explain its habitat preferences (as far as is known). Larval cases were found readily, with all attending seeing the cases in situ. We have speculated that this species could occur more widely in the Broads, but potential habitat is beyond the reach of most recorders. However, site managers should be able to access more inaccessible parts of reserves or other potential sites. There has already been a positive outcome from this workshop as larval cases have been found at a new site in a river catchment where it has not been recorded previously, by the RSPB warden of the site.

We have been working with the editor of Atropos (Mark Tunmore) preparing the summary account and full results for Moth Night 2013. This will appear in the next edition of the journal, which will be published at the end of March. With such a substantial recording effort over the country, Moth Night can provide some clues to current species trends. One of the many interesting findings from this particular event was the occurrence and numbers of species such as the Processionary Thaumetopoea processionea and Gypsy Moth Lymantria dispar (48 and 3 respectively). Neither species were recorded in 2007, the last time the event was held at that time of year. As readers will be aware we have been involved trying to bring about a more sympathetic approach to the control of Oak Processionary in this country and one that takes the biodiversity impacts of this control into account. This involves working with a range of organisations involved in the current control efforts. The results from Moth Night 2013 mostly included records of Oak Processionary from known areas, although one was from a new site and a significant step away from known populations. Forestry Commission have been informed of the location (with the agreement of the original recorder) and they intend to survey the area to get a better understanding of the species’ status in the area – an appropriate first step. Natural England has also been informed. Whilst on the topic of Moth Night, it is worth taking this opportunity to highlight that Moth Night 2015 takes place on 10 to 12 September with the theme of migration, see www.mothnight.info

Other site visits have taken place over the month, these have included being shown around a Dorset heathland site by National Trust staff looking for potential habitat for the Speckled Footman Coscinia cribraria (it is planned to trap this site for the moth later in the year). A further meeting with Forestry Commission and Natural England staff was undertaken to discuss management for Dingy Mocha Cyclophora pendularia and in particular to try to resolve grazing issues at a site where this is impacting upon the moth’s habitat. The sole site known to support Coleophora wockeella, this a BC reserve, was visited following on from management work targeted at the species over the last couple of years to quickly assess the habitat for the moth, with small larval cases being found. A Sussex site for Barred Tooth-striped Trichopteryx polycommata was surveyed on 20 March and, despite cold conditions, two adults were found, with the site management appearing good. We have been working with Stephen Palmer on a potential wind farm development off the Lancashire coast, the cable land-fall going through (or rather underneath) the Belted Beauty zonaria site. Stephen accompanied a representative of DONG Energy and a consultant to the site to discuss the proposed monitoring of the moth that will be undertaken as part of the mitigation for the works on the site in relation to the cable landfall. Other site issues have involved staff time, for example we are currently involved in work on a Planning Application which potentially impacts on a Fiery Clearwing Pyropteron chrysidiformis site in Kent.

The Wider Countryside Butterfly Survey (WCBS) is run as a partnership between Butterfly Conservation, the British Trust for Ornithology (BTO) and The Centre for Ecology and Hydrology. Butterflies are counted by Butterfly Conservation volunteers in random 1km squares across the UK at least twice a year during July and August and BTO volunteers’ record butterflies on their random 1km Breeding Bird Survey (BBS) squares. Participants of the WCBS are also encouraged to record day-flying when they visit their squares. The results from 2014 have recently been compiled, with moths counted in 202 (25%) of the squares, 102 fewer than 2013. In total 821 individuals of 44 species were seen, three more species than last year. For the sixth year in a row Silver Y Autographa gamma was the most widespread moth occupying 23% of squares, followed by Six-spot Burnet Zygaena filipendulae (20%) and Cinnabar Tyria jacobaeae (20%). The most abundant species were Six-spot Burnet, Cinnabar and Silver-Y which accounted for 31%, 14% and 8% of all moths respectively. The largest number of moths recorded in a square was 109, all of which, bar one, were Six-spot Burnet; these were seen near Edwardsville in the Taff Valley, South Wales. The greatest number of species recorded in a square was six; this near Leadburn, Midlothian. In total the WCBS generated 129 new 1km square records for 32 moth species. All of the WCBS moth data will be repatriated to County Moth Recorders for inclusion in local datasets and ultimately the National Moth Recording Scheme. Many thanks to everyone who takes part in the WCBS, if you want more information the recently produced 2014 WCBS newsletter can be downloaded here.

Cooler nights continued over much of the month, but with the occasional milder evening. Although numbers recorded were on the lower side for much of March, diversity started picking up as the month progressed. The early half of March saw reports of typical spring species, including Hebrew Character Orthosia gothica, Common Quaker O. cerasi, Small Quaker O. cruda, Twin-spotted Quaker Anortha munda, Clouded Drab O. incerta and Early Grey Xylocampa areola, along with Yellow Horned Achlya flavicornis, Early Moth Theria primaria, Double-striped Pug Gymnoscelis rufifasciata, Engrailed Ectropis crepuscularia, Early Thorn Selenia dentaria, Oak Beauty , Small Brindled Beauty Apocheima hispidaria, March Moth Alsophila aescularia and Shoulder-stripe Earophila badiata, with reports of hibernating species including Red Sword-grass Xylena vetusta, Pale Pinion Lithophane socia, Grey Shoulder-knot L. ornitopus, Dotted Chestnut Conistra rubiginea and Oak Nycteoline Nycteola revayana. A very few Dark Sword-grass Agrotis ipsilon were also reported in Dorset. In Scotland the Rannoch Sprawler Brachionycha nubeculosa started appearing just after the middle of the month, including a record from what appears to be a new site for the species. Scarlet Tiger Callimorpha dominula larvae have also been found, perhaps a sign that things are beginning to warm up! There was also a curiously early report of a Cabbage Moth Mamestra brassicae in Sussex (see Sussex Moth Group website) and one of a Pale Tussock Calliteara pudibunda in Devon, this on 23 March.

Please don’t forget that our Humming-bird Hawk-moth Macroglossum stellatarum Survey is still running. This simple online survey is extremely useful and also enables us to raise the profile of moths using a striking species which could easily be encountered by members of the public. At the time of writing there have been 25 sightings reported in 2015. For further information or to take part click here.

The larval stage of Psychoides filicivora can readily be found this time of year under the fronds of various ferns, including male-fern and soft shield fern. They feed from within an untidy mass of sporangia, occasionally making an irregular blotch mine. The larvae of the related P. verhuella can also be found, these mine the frond initially later feeding amongst the sporangia. These larvae can be distinguished from those of P. filicivora as they have a black head. For images of both see www.leafmines.co.uk and www.ukmoths.org.uk.

A final snippet: a recent report on new research discredits the belief that street lighting is attractive to common bats. This was based on the assumption that bats benefited through feeding on that congregated around street lighting.

The Moth Team