Llanelli Naturalists Newsletter - Winter 1990/1991
Warm sunshine and gentle southerly winds "from south of the Azores" (BBC weather forecast) brought the first spring sighting of a red admiral Vanessa atalanta and a painted lady Cynthia cardui (as well as the season's first chiff-chaff) at Pembrey Forest 22/395015, on 9 March. Immigration of red admirals and a few painted ladies continued throughout the unseasonally hot weather of late March (when temperatures reached 18°C on the 30th), and, as in SW England (Bowles, 1990) these migrant butterflies were accompanied by an exotic species of bird - a resplendent hoopoe (that was found at near Cilymaenllwyd, Pwll (22/482022)) in mid-month, and also the hummingbird hawk-moth Macroglossum stellatarum, which was noted at a scattering of Dyfed localities including Cwmpengraig, Felindre 22/348367 on the 30th (S.J. Adams). The warm weather also tempted early emergences of several resident species in mid-late March - peacocks Inachis io, small tortoishells Aglais urticae, and speckled woods Pararge aegeria, with commas Polygonia c-album, orange-tips Anthocaris cardamines, and holly blues Celastrina argiolus first showing themselves in the first week of April.
At this time too, another characteristic herald of spring - the brimstone Gonepteryx rhamni was seen at more than half-a-dozen sites throughout eastern Carmarthenshire, from near Halfway 22/827328 (near the Brecon border, B. Stewart), on the limestone ridge and other base-rich localities (where its food plant, buckthorn Rhamnus cartharticus is an unobtrusive component of the shrub layer) to regularly-noted brimstone sites on the coalfield, where instead, alder buckthorn Franqula alnus is probably utilised by its caterpillars.
Other species had emerged by late April and early May with, for example, many records of green-veined whites Pieris napi and small coppers Lycaena phlaeas and, on 2 May the enchanting sight of green hairstreaks Calophrys rubi feeding at flowers of green-winged orchids Orchis morio on stable dune grassland at Pembrey Burrows 21/41-99-.
A positive feature of the county's butterfly fauna is the continuing survival of colonies of marsh fritillaries Euphydryas aurinia, a species which "has declined very severely in recent years" throughout Europe (Warren, 1990) as some 97% (in Britain) of its habitat (agriculturally-unimproved lowland grasslands) have been destroyed (Fuller, 1987). Its decline has been so rapid and so extensive that it was one of only three British butterflies (the others being the extinct large blue Maculinea arion and the artificially-maintained large copper Lycaena dispar) to be listed for protection under the "Bern Convention", which obliges signatory nations (which includes Britain) to conserve important wildlife habitats (Warren, loc.cit.). This sad decline re-emphasises the importance, in a national context, of the marsh fritillary colonies in Dyfed (c30 currently-known sites in Carmarthenshire, 9+ in Pembrokeshire (Evans, 1989) and a substantial number - including some important colonies - in Ceredigion, where the species has been thoroughly surveyed (eg Fowles, 1986). The coalfield areas of western and northern Glamorgan, which are mostly rather poorly surveyed for invertebrates, probably also hold - judging by the extent of surviving habitat - colonies of marsh fritillaries.
4However, colonies continue to be lost, whether by agricultural grassland improvement, afforestation or open-cast coaling.
A modest colony is established on certain pastures at Cencoed-uchaf farm 22/485032 where negotiations are underway to conserve this site by appropriate management; here the butterflies were first noted on 24 May (they typically emerge at this time). There were five 'new' colonies discovered in 1990: (i) Waun-wyllt, Horeb 22/498055 (a strong colony also with small pearl-bordered fritillaires Boloria selene on 26.5.90); (ii) a meadow next to the Afon Marlais 22/613176 at Derwydd - 20+ adults subsequently seen, with larval webs' also later found (N.R. Mathew); (iii) two adults noted flying with small pearl-bordered fritillaries at Penrhiwiau plantation 22/665235 (NRM); (iv) one noted, at the start of the flight season, at Cors Goch Llanllwch Nature Reserve 22/364185, (P. Whitton); and (v) one seen at the edge of Llyn Pencarreg 22/536455 on 27 June (Julian Friese, J.F.). An updated, distribution map for the marsh fritillary is given (see fig.1)
- post 1970 tetrad record
* - pre 1950 10km record
O - 1950-70 10km record
Small pearl-bordered fritillaries were noted at a minimum of fifteen widely-spread localities during the season, including several new stations; this is another species characteristic of flower-rich grassland in south-west Wales.
In contrast, the pearl bordered fritillary Boloria euphrosyne is a species that probably is almost extinct in most parts of the county, though until the first part of this century it was considered common (Morgan, 1989a). Its larvae utilises "young violets that have recently sprung up in bare ground, or which are growing in a warm, sheltered micro-climate" (Thomas & Snazell, 1989), and the decline in various forms of woodland management, in Dyfed (and elsewhere) which results in heavily-shaded woods, rather than open, sunny conditions, must have adversely affected this species.
was fascinating to hear of half-a-dozen or so probable pearl-bordered fritillaries in a glade at a small wooded 'cwm' near Cynwyl Elfed (by the old waterworks 22/385258 (JF)), for this is exactly where B.L. Thomas noted the species in 1951-2; this site will be checked next season to validate this interesting record; other 'possibles' were noted in Carmel Woods (22/61) in May (NRM - it would also be useful to determine its status at this threatened site), and there was a definite observation of a singleton, which sunned itself in an open area near the Gwaith Go-bach pond, at Dinefwr Castle Woods 22/619220 on 29 May by Chris Smith, the Reserve's summer warden.
In contrast to the 1989 season, when there was only one sighting of silver-washed fritillaries Argynnis paphia, it is gratifying to record that this species was noted at no less than seventeen different localities during July to September including a female watched ovipositing in bark crevices on the shaded north side of Corsican pines Pinus niqra var. maritima, 1-3m off the ground in Pembrey Forest 22/392023 on 18 July. of the related high brown fritillary Argynnis adippe, there were no records (the last sighting was as long ago as 1976) and this woodland species may well be extinct. Still with us, but by no means common, is the dark-green fritillary Argynnis aqlaja, seen at Laugharne Burrows 22/301072 on 10 June, and a characteristically fast-flying individual cruising over the upper reaches of the Sawdde-fechan 22/756215 on 26 July (NRM).
It is recognized by entomologists that butterflies obtain certain salts from damp soil, pond-side sediments or even human perspiration, but a holly blue was observed on 18 July for several minutes, licking with its proboscis, old soot-impregnated mortar at Erw-las, Llwynhendy 21/537993, and a week earlier, a comma was similarly noted at dog faeces at Stradey Woods 22/490017. Similar behaviour was also observed in small blues Cupido minimus, meadow browns Maniola jurtina, gate keepers Pyronia tithonus and small heaths Coenonympha pamphilus, aggregations of which were busy probing damp sediment on a pathway which crossed a recently- evaporated dune slack at Pembrey Burrows 21/41-99-.
It was feared that the hot dry summer of 1989, which dessicated swathes of kidney vetch Anthyllis vulneraria at Pembrey Burrows would lead to a severe decline in numbers of small blues (whose caterpillars feed on that plant), but casual observations happily showed that fair numbers (both spring and late summer broods) were present at this site in 1990. However, a mystery surrounds the disappearance of small blues and marbled whites Melanargia qalathea from two inland colonies - Capel Dyddgen quarry 22/467127 and Carreg Eidon 22/493137 (Mynydd Llangyndeyrne) - where they were present in the mid-1970's, eg "small blues seen in the disused quarry south of Crwbin (near Capel Dyddgen) where there were many marbled whites and graylings Hipparchia semele"(personal diary entry, 28 July 1975). Yet, two season's searching has failed to reveal marbled whites or small blues at these two localities. One can only postulate that increased grazing pressure by rabbits has mostly removed the kidney vetch from these sites (though it just survives at Carreg Eidon), as well as the rank grasses favoured by Melanargia, though expectedly, the grayling, which favours open bare conditions, is still frequent. As compensation though, two new localities were discovered that held marbled whites - with six individuals at Derwydd station 22/621178 (on waste ground, 20 July, (NRM) and 30+ on rank grassland at Cae Tir Mawr 22/648205 on 25 July. An old record of the marbled white in Carmarthenshire has only recently come to light. In 1894, T.A.W. Rees wrote that, "across the river on the upper meadows near Dollan (near Llandysyl, 22/422409), is to be found the marbled white..., this spot being one of the Welsh homes of this lovely insect, which is also found somewhere between Tenby and Carmarthen" (Rees, 1894). This is not the only old reference to the marbled white in the Llandysyl area as W.J. Davies listed the species in his 'Hanes Plwyf Llandysyl, (Davies, 1896), and there is the recent record of one at Penlan, Cenarth 22/258414 on 16 July 1986 (C.M. Laird) - does the marbled white still survive on meadows somewhere in the Teifi catchment, either in Carmarthenshire or neighbouring Ceredigion?
Holly blues and commas both had good years, with the latter wandering widely in search of pre-hibernation sustenance in late summer, away from their scrub or woodland wintering/breeding sites, and this season there was also a resurgence in the general numbers of common blues Polyommatus icarus; the brown argus Aricia aqestis, which has been overlooked at its coastal stations in the last couple of years, was noted in mid-September by Jayne Kelsall in the Pembrey Forest area (at 22/398023 and 22/414019); here in the disturbed sandy trackways, the larval food plants - storksbills Erodium spp. abounds. Graylings, walls and several other reasonably-common species were all noted in their usual haunts at appropriate times, but apart for the early spring influx, it was a poor year for migrants with no clouded yellows Colias croceus reported (though they reached Lundy Island in the Bristol Channel, B.S. pers.comm.), with just a small August influx of painted ladies, but good numbers of red admirals again in the early autumn.
There were several records of purple hairstreaks Quercusia quercus at various scattered localities including individuals coming down to the water's edge along the R. Sawdde 22/728245 at Pontarllechau, and the nearby Sawdde-fechan had 'considerable numbers...amongst the oaks', (NRM). A highlight of the season was the single white-letter hairstreak Satyrium w-album caught by the streamside in the base-rich 'cwm' at Coed Penrhiwiau 22/660237 on 24 July, here its' caterpillars must feed on the strong growths of wych elm Ulmus glabra and since this tree still thrives in many other base-flushed dingles, one can be optimistic that the white-letter hairstreak still survives, undetected, elsewhere in the county's woodlands. Another elusive species is the brown hairstreak Thecla betulae, one of which was closely watched by Rob Colley on a flower of clover growing on the old railway track at Dryswlyn 22/552199 on 22 August, this species is probably widespread - if again mostly unseen - in small numbers throughout much of Carmarthenshire; certainly it's larval food-plant (blackthorn) grows commonly in the wood-edge situations that the butterfly often favours.
References and Sources
BOWLES, N. (1990) - Wildlife Reports: Butterflies. British Wildlife 1, No5 295-26.
DAVIES, W.J. (1896) - Hanes Plwyf Llandysyl (Llandysyl Parish History): 331-2.
EVANS, F. (1989) - A review of the management of lowland wet heath in Dyfed, west Wales. NCC contract survey No42, NCC Peterborough 1989
FOWLES, A.P. (1986) - A site dossier for marsh fritillary colonies in Ceredigion since 1983. Unpublished NCC Report.
FOWLES, A.P. (1986) - The Moths of Ceredigion. Research and Survey in Nature Conservation, No8. Nature Conservancy Council.
FULLER, R.M. (1987) - The changing extent and conservation interest of lowland grasslands in England and Wales: A review of grassland surveys 1930-84. Biol. Conserv. 40:281-IOU
MORGAN, I.K. (1989a) - A Provisional Review of the Butterflies of Carmarthenshire. Unpublished Report NCC Dyfed/Powys Region.
MORGAN, I.K. (1989a) - Carmarthenshire Butterflies and Moths 19 Dyfed Invertebrate Group Newsl. 12:4
MORGAN, I.K. (1989a) - Dyfed Site Report No7 - The Stradey Estate, Carms., 22/488016. Dyfed Invertebrate Group Newsl. 15:7-10
REES, T.A.W. (1894) - Butterflies in mid-Wales. Science Gossip (New Series). 1:103
THOMAS, J.A. & SNAZELL, R.G. (1989) - Declining fritillaries: the next challenge in the conservation of British butterflies. Institute of Terrestrial Ecology, Report 1988-9: 54-56
WARREN, M.S. (1990) - European butterflies on the brink. British Wildlife 1 No4: 185-196.