It was a couple of years ago I think that some of our Norfolk colleagues mentioned finding Six-belted Clearwing on vegetated shingle sites. On Friday I popped up to Aldeburgh beach and had four come to pheromone lure. Conditions were not ideal with quite a stiff breeze blowing down the beach.
I moved onto Sizewell beach and although there is a bit of Bird’s-foot Trefoil up past the reactor no clearwings came to the lure. It had started to cloud over by this time so that could well explain the lack of response. I had a similar negative result at Dunwich Beach. It would be worth trying these latter two sites with better conditions to be a little more certain.