It's that time of year again when these little 'beauties' are around and getting worn.
If you find one you are having trouble with, the underside of the fore-wing can be of help and is usually easy to see when it is in a pot.
The very tip of the fore-wing has a small, square'ish, light coloured patch. We caught this one this morning and having chased it round the conservatory a couple of times it finally agreed to become a model. The first photo also shows the antenna detail mentioned in the field guides.