Llanelli Naturalists Newsletter - Winter 1991/1992
Ian Morgan

After two successive summers of sunshine, 1991 was a disappointing year in terms of prolonged warm weather, indeed some weeks in late spring were decidedly cold and wet. An unfavourable spell for example, coincided with part of the flight period of the marsh fritillary Eup ydryas aurinia; nevertheless, three new sites were located: Pumpsaint 22/634404 (one tattered individual on 28 July), Carreglwyd 22/680227 10/7, (both Julian Friese, J.F.) and at Gilfach-wen, SE of Llanybydder 22/530429, 4/7 (George Hutchinson). Other records were from, or close by to known colonies on the Coalfield around Capel Hendre 22/58-11- & 22/57-12- (P. Whitton, P.W.).

The site (Cwm Tawel 22/385257) behind the "Rock and Fountain", Cynwyl Elfed, where possible pearl-bordered fritillaries Boloria euphrosyne were reported last season was checked, but only a few small pearl-bordereds B. selene were present, in an open area surrounded by oak woodland, below the old reservoir. Firm records though, of pearl-bordereds were received from Luke Gravett (L.G.) who saw up to five around the coastal limestone ashwood 22/226081 to the west of Pendine on 26 May. Small pearl-bordereds and both dingy Erynis tages and grizzled skippers Pyrgus malvae were also recorded here in 1991, on grassland at the mouth of the valley. The grizzled skipper is now rather a rare species of coastal Carmarthenshire (where it inhabits dune or cliff grassland) but there are also a very small number, of mostly old, inland records. The dingy skipper has a similar distribution, though it still occurs inland where it characteristically forms discrete colonies in old limestone quarries etc.

Silver-washed fritillaries Argynnis paphia again had a reasonable year, with a number of scattered records, mostly from known areas such as the heavily wooded valley between Abergorlech 22/58-33- and Brechfa 22/52-30-, or the Sawdde Gorge 22/72-24- etc, where up to eight were watched on 25 August (JF). A strong colony was also present in Pembrey Forest (especially at 22/395007), and it is interesting to write that this colony (or colonies in the vast Forest area) must be comparatively newly-established (ie post-1928, when the Forest was initially planted). Coniferisation has been blamed for the destruction of other silver-washed colonies when broad-leaved woods have been planted up with conifers, but here, forest establishment has favoured this species (though probably simultaneously depriving the dark green fritillary Argynnis aglaja an open ground species, of it's habitat!). Silver-washed fritillaries are said (Thomas & Lewington, 1991) to favour sunny woodland with an open canopy, and compared to the other fritillaries it is quite mobile - a factor that presumably enabled it to successfully colonise Pembrey Forest.

Another woodland butterfly - the purple hairstreak Quercusia Quercus - was reported from three sites: Porthyrhyd near Llanwrda 22/717367, late July; Pontynyswen 22/536246, 16/8; and Trecynllaeth near Glanaman 22/684145, 26/8 (all JF). 0n more open terrain, green hairstreaks Calophrys rubi were noted amongst a favoured habitat - growths of gorse and bilberry on a rough, south-facing slope near Glanamman 22/657146 on 12 May (JF) and at the marsh fritillary colony near Cencoed-uchaf 22/486032 on 31 May (1,0). Probably one of the stronger colonies of dark green fritillaries in Carmarthenshire is that on the eastern edge of Tywyn Burrows, particularly the "bee-orchid ride" 22/371035; here, on 21 July, at least fifteen energetically- flying individuals were counted by the author and P.M. Pavett.

Holly blues Celastrina argiolus had another good year, with a wide distribution of records, including some from urban settings such as the female ovipositing on tangles of ivy (one of it's larval food plants) on an old school wall at Bigyn Hill 21/510998 on 15 August. The holly blue is regularly observed in gardens, where the alternative food plant - holly - is often cultivated; apparently, holly is favoured for egg-laying by the spring brood whilst ivy is utilised by the summer brood of adults.

Commas Polygonia c-album continue to do well, with this species providing the earliest butterfly sightings in mid-March and also the latest in 0ctober. It genuinely seems - judging by the frequency of records - that the comma is now more numerous than even only a decade ago. At the turn of the present century, the comma was a rare (or even extinct) species in many parts of it's British range, with Barker (1905. for Carmarthenshire, giving only a few records and later, Brunker (1959) recalled that..."the first I saw was in 1911, and it was silhouetted in the window blind of the "Butchers Arms" Inn, Carmarthen... I did not see another specimen until 1936 at Llanegwad." Certainly nowadays, the distinctive comma is a regular member of our woodland edge butterfly fauna, a pleasing example of a species that has increased rather than declined.

Updated map showing the known distribution of the marbled white  in CarmarthenshireAlthough known to be strongly established on the coastal dune grasslands, on the Coalfield and on the Carboniferous limestone outcrop, the Carmarthenshire distribution of the marbled white Melanargia galathea is not yet fully elucidated, for there are scatterings of records (sometimes of good numbers of individuals in clearly-established colonies) from rough grassland sites away from the main centres of distribution. For example, a solitary individual was seen flying by the writer alongside the rank grassy verge that borders the commonland heath at Mynydd Ystyfflau-carn 22/470271 on 12 August and earlier, others were seen by K.S. Sheridan ovipositing amongst tall grasses on the opposite side (22/470263) of the same common. Marbled whites were also reported from a few new localities (as well as from already-recognised sites) on the Coalfield at Capel Hendre, Cefneithin, Penygroes, Cathilas near Ammanford, and also to the SE of Gelli-uchaf 22/478178 (Alison Cox & PW)

In the south-east, there were the usual springtime sightings of brimstones Gonepteryx rhamni usually the brightly-coloured yellow males, with records from the upper Lliedi Reservoir 22/510049 (JR Ellis), Stradey Woods 22/495014, near Burry Port harbour 22/445006 (JF) and south of Pont Abraham 22/57-06-.

24Again no clouded yellows Colias croceus were reported in 1991, and apart from the painted lady Cynthia cardui seen on Tywyn Burrows 22/36-05- on 28 April, the only migrants were more painted ladies and many red admirals Vanessa atalanta in August-September, when they were accompanied by vast numbers of diurnally-active silver-Y Plusia gamma moths.

References

Barker, T.W. (1905) A Handbook to the Natural History of Carmarthenshire. W. Spurrel & Son, Carmarthen.

Brunker, J (1959)    A half-century of natural history. Trans. Carms. Antiquarian and Field Club 1:194-199, 4:70-73

Thomas J. & Lewington, R (1991) The Butterflies of Britain and Ireland. Dorling Kindersley and the National Trust.