does hind-margin = costa? or ??? OK I've looked up your website. [Thank you for the resource] It is not on your diagram I use for wing parts "names of areas of a wing". So I learn hind-margin a.k.a. inner-margin. I hated organic chemistry because of the multiple nomenclature! OK, spots on this moth. I am not sure that the 'spot' on the inner margin is part of the moth. It looks like a highlight due to sunlight going through a small hole in a leaf. The 'v' at the end of the thorax (near the base) - insert shoulder shrug - sticking up scales? The only other 'spot' I can in the vicinity of the costa near the base is I think hairs on the cleavers plant it is standing on out of focus and glinting.