I came across this larva on 8 6 14 half a mile up the road towards Newquay from Cwm Tydi. It was on a blackthorn bush by the cattle grid. It was all alone. There were no signs of an old festoon and no twigs stripped of leaves. Back in 2007 I had found a very similar looking Yellow-tail larva a few hundred yards away down the track (and sent the record in). The larva was quite well behaved, ie it didn't curl into a ball, fall to the ground and disappear. So I took a lot of photos hoping for at least one good one. However it was rather mobile.
It wasn't until I downloaded the photos and had a good look at them that I decided it was a Brown-tail. The distinguishing marks are these bright red spots on the dorsal surface of segmrnts 9 and 10. See Plate 27 Q in Jim Porter's caterpillar book. There is an even better picture in Chris Manley's lovely new book 'British Moths and Butterflies a photographic guide'. Pge 304. A whole swarm of them about the same instar.
The confirmation is required as there are no previous Ceredigion records. (None in Pembs vicecounty either).
I hope some off-field adjudicator will come through to the ref: ( Peter Walter Davies) 'You may award a try'.
Peter Byles, a Pembs moth-er.