I found a dead Lesser Broad-bordered Yellow Underwing, Noctua janthe, lying on the path in the greenhouse this morning and, as I’d plugged in my USB microscope to take a closer look at the fungus I decided to take a few shots of the moth too.
The saffron yellow underwings are a striking contrast to the drab upperwings. The border looks as if it has been painted with Impressionist brushstrokes when viewed at 60x.
I suspect that the light blue scales are reflecting daylight from the window.
Zooming in to 200x reveals comb-like ends to the scales.
Coloured scales camouflage the moth when at rest and reveal distracting colours when it is disturbed and it opens its wings. It’s also possible that the coating of scales and the furry edges of the wings help muffle the sound of the moths wingbeats, helping it escape from any bat that hunts by sound alone.
I put it under the microscope to focus on the eye-spots. Each has a bright fleck in the middle, even the smallest of them, which must help give the impression of a gleaming snakelike eye, distracting any attacker either by surprising it or fooling it into pecking the butterfly’s wing instead of its body.