Rosy Knot-horn Oncocera semirubella

This species was previously assigned the vernacular name Rosy-striped Knot-horn which I think is actually more appropriate. It's also sometimes known informally as Rhubarb and Custard, though that should really be Custard, Rhubarb and Cream.

This species is increasing in Norfolk and appears to be breeding in the Brecks and probably elsewhere (e.g. Flitcham). It was a species I was longing to find, so was delighted when one appeared on the top of my moth trap while I was going through it one morning. It must have made its way out of the trap while I wasn't looking as it hadn't been there earlier. I took a single photo and looked back only to see that it had vanished. Afraid that the flash had flushed it and I'd missed the shot I checked my camera and was relieved to see that I had got it. I didn't see it again, so good job it's a very easy species to identify!

Rosy Knot-horn Oncocera semirubella, North Elmham (Norfolk, UK), 17th July 2025