Monday, 28 November 2011

The moths of Torry Bay LNR


Crescent Striped
Bird enthusiasts will know that twitchers travel to distant extremities of their home country in order to see unusual birds. The most extreme example that I know is St Lawrence Island, a small island that politically is part of Alaska but geographically is just 32 miles from the coast of Siberia. Thus, American twitchers (they call themselves listers) go to there to put Eurasian birds on their American bird list. Perhaps we have a St Lawrence Island equivalent in vc87 where we can go to see moths not otherwise recorded in the vice county. The boundaries of many vice counties are strangely erratic and the eastern boundary of vc87 appears at first sight to stop at Kincardine Bridge but in fact it extends in a narrow finger along the coast of Fife to include Torry Bay. Here then is a stretch of esturine coast that might be expected to have a moth assemblage similar to coastal Fife and Lothians. So, a list forwarded to me by Duncan Davidson of moths caught by Stephanie Little (then Stephanie Smith) in Torry Burn LNR during 1999 and 2000 was always going to be exciting. Indeed, it proved to include records of White-line Dart, Heart and Club, Lunar Underwing, Large Wainscot and Silky Wainscot; all species seldom or never previously recorded in vc87. Also on the list were two most unexpected species: Crescent-striped a salt-marsh species for which there are no recent records north of Lincolnshire and Annulet which again has no recent records from nearby coasts. Stephanie had sent all key species to Keith Bland for identification. He had examined the genitalia of all that he received and the specimens are stored at the National Museums of Scotland Collections Centre at Granton.  Furthermore, Duncan Davidson has recently visited Granton and has photographed some of the above specimens. His photographs will be placed in the Scottishmoths vc87 validation file. In addition, his photograph of the Crescent-striped is included with this blog. The moth is clearly rather worn and, without Keith Bland’s examination of the genitalia, it would be hard to be sure that it is not a Dusky Brocade. However, the forewings are rather square with very straight costa, the markings are poorly contrasted and show some suspicions of a partial white edging around the kidney spot and elements of a dark bar joining the central cross-lines. These are all characteristic features of Crescent-striped. Unfortunately, the Annulet specimen could not be found for Duncan’s visit but he informs me that E.C. Pelham-Clinton recorded it 1966 at nearby North Queensferry.

4th November – Blair’s Shoulder-knot

Blair’s Shoulder-knot first arrived in the UK (on the Isle of Wight) in 1951. It found that its preferred larval foodplants, Lawson’s and Leyland Cypress, are common garden trees in the UK and it spread rapidly. By 1996 it had reached Cumbria and by 2001 had crossed the border into Kirkcudbrightshire. Since then, it has spread to Ayrshire, the Borders, Lothians and into Fife as far north as Anstruther so it was not unexpected when one found its way into my trap in Milgavie on 4th November. I hasten to add that I would not allow C. leylandii in my garden and, if Blair’s Shoulder-knot causes grievous harm to those in my neighbour’s garden, I shall be delighted. Unfortunately, said trees are growing much faster than even a plague of caterpillars could keep up with.

Summer 2011 – Spindle Ermine

In central Scotland we regularly see Bird Cherry trees defoliated by the larvae of Bird Cherry Ermine (Yponomeuta evonymella). We do not however usually see Spindle Ermine (Yponomeuta cagnagella) because Spindle (Euonymus europaeus), its main foodplant, is a plant of calcareous soils, especially the chalky soils of southern England. Nevertheless, related species of Euonymus are less calcium dependent and are grown in gardens and one of these, Japanese Spindle (E. japonicus), is grown as a hedge and can be an alternative foodplant for Spindle Ermine. It was from a totally defoliated hedge of this shrub growing around the car park of Wickes Home Improvement Store in Stirling that on 21st May Hugh Clayden recovered pupae and larvae and sent them to the author. They hatched into Spindle Ermine a new species for Stirlingshire.