The larvae of the Pyralid Mecyna asinalis (Madder Pearl) feeds on Rubia peregrina (Wild Madder), forming windows on the leaves. I'm pretty certain this is the feeding damage observed at Wyndcliff on Friday. Surprisingly, I can only find one previous VC35 record of this species, from Caerwent, although I have a nagging doubt someone else has reported it here. Wyndcliff is really regularly trapped, so it would be odd for this distinctive moth to have been overlooked there. All in all, a bit of a mystery.