I saw my first Orange Underwing of the year this afternoon. On my way back into Cardiff I stopped to look on the bracken slope to the north of Coryton Interchange, where there are a number of birches, and saw a single Orange Underwing flying around the top of one of them at 4:15pm. This appears to be the earliest record for VC41, the previous earliest being 15 March 1999 when Richard Pryce saw one at Bedlinog.
I also checked the pylon ride through Greenmeadow Wood, just to the north of the bracken slope, but didn't see any there. I saw good numbers in this area on 23rd March 2012, so they are probably only just starting to emerge.