There does look to be a large difference in size. The documented spread in size is 19mm to 23mm. Measuring the wing length of your moths on my screen gives lengths of 3mm and 3.5mm, which gives a ratio very close to 23 over 19. So I think these are the Little and Large of Feathered thorns.
Thanks Tony. I think your measurements are spot on. The squares are 6.5mm. I've measured one I trapped on 11th November and that was 28mm, again on the large side.Of the listed foodplants, there are Hawthorn, Blackthorn, Hazel and Crab Apple in the immediate vicinity of the trap. Perhaps one of these is particularly nutritious and leads to big fat larvae and large moths. My guess would be the Crab Apple. There must be a PhD for someone there?