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Thursday, 3 July 2014

Toward Pwll Uffern - a return visit to Cwm Pysgotwr, 2.7.14.

Yesterday, Nigel Stringer and I re-visited Cwm Pysgotwr in NE Carmarthenshire, a steep-sided valley that lies along the border with Ceredigion. My purpose was to search for diurnal moths, whilst Nigel indulged in his recording of fungal rusts. Only eight species of moth were seen, but three species were noteworthy.
The valley, especially the Carmarthenshire side, is now ungrazed and has a profuse regeneration of heather, bilberry, young birch and rowan (though ideally the colonisation by trees should be controlled, as good heathland is a more deserving habitat than secondary woodland).

Above: view of the Carmarthenshire side of the Pysgotwr....ideal black grouse habitat if there were any  around! At c SN753489, looking NW.

Above: higher up the slopes - Not for those with vertigo! By now, I was regularly flushing large numbers of a rather scarce and local moth. I also flushed a noctuid from this slope, but obviously could n`t run after it...I bet it was something good!

What was the moth that I was regularly flushing from the heather and bilberry? It was the smoky wave and I estimate that I flushed 50+ and could have very easily flushed many more, were I have continued walking the slopes. There would have been hundreds in the heathy vegetation.

Above: smoky wave in situ in the bilberry - click photo to enlarge. They were quite flighty and I did n`t have the time to stalk the moths; however, they were easy to net, simply because they were so numerous. One even landed on my nose! (if I was squint-eyed, could close-focus and had a long enough nose, I`d have a grand view!).

Above: two different individual smoky waves, showing slight difference in wing-barring.

Grass moths were abundant, especially Chrysoteuchia culmella (in many hundreds), C. lathionellus (x c10) and a single C. margaritella.
A couple of galium carpets were seen (but not caught) in areas of heath bedstraw, where a solitary small argent and sable was spotted and, with an element of luck (and deft netting), caught.

                                         Above: small argent and sable.

                        The above micro was seen with some frequency. Is it Celypha lacunana?

I also ventured on to the Ceredigion (vc46) side of the river at the start of the ravine higher up the Pysgotwr and smoky waves were also seen there, together with three small pearl-bordered fritillaries (also seen on the Carmarthenshire side of the river). Generally, in Cwm Pysgotwr, ringlets were common, as were meadow browns and large skippers, with lesser numbers of small heaths.

Above: looking back down the Pysgotwr at the start of the ravine from the Ceredigion side. The crags of Cribyn Du on the top right-hand side. SN751493, looking SE.

             Above: looking the other way (cNW) from the site shown in the previous photo.

Finally, on the way up to Cwm Pysgotwr in the Allt Rhyd y Groes NNR, we stopped off at the meadow where we saw chimney sweepers last year. We saw none, but then on our return journey, Nigel happened to spot one, which was rather fitting as it was he who originally found this colony back in July 1997. With or without chimney sweepers, it`s a nice meadow:

                                         Above: The Allt Rhyd y Groes meadow SN764481.


  1. Wouldn't it be great to get a trap in there. Looks wonderful.

  2. Wonderful to get proper documentation of what smoky wave does in carms.

    Yes that's lacunana

  3. The area will be fantastic for moths. RSPB staff (mostly seasonal wardens with a moth interest as I understand it) did some survey work in the general area in the 1970s-80s and there was a smoky wave record from adjacent Allt Rhyd y Groes in 2006 ) of a single, I recall).