Llanelli Naturalists Newsletter - Summer 1993 - No 55
Ian Morgan

To naturalists visiting the broad, coastal burrows of Carmarthenshire, the marbled white Melanargia oalathea is a familiar and easily-recognized species with its chequered black-and-white wings and characteristic slow, bouncing flight. This atypically-coloured member of the Satvridae (the "brown butterflies") is on the wing from the end of June to mid-August, with maximum numbers flying in about mid July. Although it was once thought that the caterpillars eat a wide range of grasses, it is now considered that red fescue Festuca rubra or sheep's fescue F. ovina are essential, at least to the young larvea (Wilson, 1985). Hardheads Centaurea nicra are a favourite source of nectar for the adult butterflies and indeed this is often a common flower on the neutral grasslands - whether hay meadows or coastal dunelands - which the marbled white prefers.

Although some further stations have since come to light, the distribution of the marbled white both on the coast and on the outcrop of Carboniferous limestone and the Coal Measures is comprehensively covered in the "Provisional Review of the Butterflies of Carmarthenshire" (Morgan, 1989). The main purpose of this short paper is to provide a list of localities away from the afore¬mentioned strongholds where the marbled white has been recorded both in the past and in more recent years. In the "Provisional Review" it was suggested that "the handful of records of individuals elsewhere in the county may represent dispersing adults or they may be from unknown local colonies...". Certainly, in the last few years, discrete colonies have been found well inland in Carmarthenshire and It is thought that other small colonies await discovery, particularly on the neutral soils of the Teifi catchment. More fieldwork could perhaps be profitably undertaken during the flight period of the marbled white in northern Carmarthenshire, remembering that colonies can be small and very localised; there may also be the possibility of colonies existing on the Ceredigion side of the Teifi valley.

Table 1:    Known inland marbled white colonies in Carmarthenshire :excluding the Carboniferous limestone/Coal Measures)

  1. "Upper meadows near Dollan.", Llandysyl 22/422409, T.A.W. Rees, c.1894 (Rees, 1894). (N.B. - W.J. Davies in his "Hanes Plwyf Llandysyl" (1896) also mentions the occurrence of this species in the adjacent Cardiganshire parish of Llandysyl).
  2. Penlan, Cenarth 22/258414, 16 July 1986, C.M. Laird, a singleton only.
  3. Cwmpengraig, Felindre 22/351372, 21 July 1991 (and other dates including 1992), S.J. Adams, a small colony on a steep meadow.
  4. Mynydd Ystyfflau-carn (i) 22/470271, 12 Aug 1991, I.K. Morgan - one individual flying along a grassy roadside verge, and (ii) ovipositing individuals on an old meadow at 22/470263 (1991) - K. Sheridan.
  5. "near Abercothi" c.22/50-20-, c.1950, J.Brunker "local but abundant where it occurs".
  6. near Llanarthne 22/53-20-, 1922, C.Tait, along railway line (site now unsuitable as it is too tightly grazed).
  7. near Llanybri 22/33-12-, 1951, Hunter & Twimm - one swift flying female, caught "no others were seen, in spite of a search of neighbouring fields".
  8. Derwydd Station 22/621178, 20.7.1990, N.R. Matthew. Six butterflies on rank grassland near former station platform.
  9. Cae Tir Mawr SSSI 22/648205 SE of Ffairfach, 25.7.1990, I.K. Morgan, c.30 noted.
  10. Dinefwr Park 22/613223, 1990 onwards, I.K. Morgan et al, several on rank grassland in deer park.
  11. Tir Philip near Nantycaws 22/48-18-, c.1980, Mrs S. Cowdy, "several".
  12. Pen-ty meadows, NW of Llanddarog 22/483160, July 1989 & 1990 I.K. Morgan, "several".
  13. Cennen Tower 22/675214, 21 & 22.7.1992, D.Gray & J.Bevan "small colony".

Acknowledgements: Gratitude is due to those naturalists who have taken the trouble to communicate their records. Thanks also to Richard Pryce for preparing the tetrad distribution maps.

References:

Morgan, I.K. (1989). A Provisional Review of the Butterflies of  Carmarthenshire. NCC internal publication, Aberystwyth.

Rees, T.A.W. (1894). Butterflies in Mid-Wales. Science Gossip (New Series)  1894 1:103.

Wilson, A. (1986).    Flavonoid pigments in the marbled white butterfly (Melanargia galathea) are dependent on flavonoid content of larval diet. J. chem. Ecol. 11:1161-1179