Another Early Grey

I have another Early Grey this morning by the door. The markings show it to be a different one to the one I saw a few days ago. The moth was in a more accessible place, I got much better photos this time.

There was one Small Tortoiseshell butterfly in the garden as well.

Early Grey - Xylocampa areola

Detail 1

Detail 2

As I was looking at the photos, I saw that the scales are wider at the outside edge and also have small protrusions. I've noticed it before but never really thought about it. I did a little research on moth scales. I suspect they are tapered to help them form a dense heat keeping layer, as they will be packed closer together nearer the body. The ragged edges are I assume, to help with
aerodynamics. This is conjecture on my part, if anyone knows more about this, I'd love to hear it.

I found a nice photo of moth scales on Wikipedia in the public domain. I thought I should put it on here out of general interest. I should mention that I added the text to help make the image more understandable. The photo and the URL are below.

From: https://en.wikipedia.org/wiki/Scale_(insect_anatomy)