Common Buckeye Butterfly (Junonia coenia) — Image by kenne
So, I begin researching articles on butterfly color and found “The evolution of color:
How butterfly wings can shift in hue” in ScienceDaily. They found that buckeyes
and other Junonia species can create a rainbow of structural colors simply by tuning
the thickness of the wing scale’s bottom layer (the lamina), which creates
iridescent colors in the same way a soap bubble does.
“In each Junonia species, structural color came from the lamina. And they are producing
a big range of lamina thicknesses that create a rainbow of different colors, everything
from gold to magenta to blue to green,” says first author Rachel Thayer.
“This helps us understand how structural color has evolved over millions of years.”
You can find more information structured color at Marine Biological Laboratory.
(Please note, I’m a photographer, not a biologist.)
— kenne