Butterflies and moths belong to the order Lepidoptera and all members have scales covering their bodies and wings (in Latin, lepis means scale and ptera means wing). With over 180,000 described species, the Lepidoptera are not only diverse in their numbers but also in coloration. Their colors arise due to the nature of the scales they produce and can be due to pigmentation as well as structural color. Whatever the origin, color results from an interaction between light and matter.
The wings of a butterfly are covered in overlapping layers of scales which are composed of chitin. In this image you can see the orange scales through magnifying a wing 140X.
But not all wing colors arise due to pigments. The metallic blue morpho butterfly gets its color due to the nanoscale structures on its wings. Check out this YouTube video for more information on structural color.
Here's a compilation of butterfly and moth wings I've taken a closer look at using macro photography and the Foldscope at 140X magnification. See if you can figure out which are caused by pigmentation and which are caused by structural color!
Red wings are likely due to pigment production. Pigments typically create "hot" colors from red to yellow.
Structural colors usually produce "cold" colors from near ultraviolet to blue-green.
The green scales on the uraniid moth turn purple when we zoom in. This is likely due to the structural nature of the scales - light is coming in at a different angle and thus changes to a purplish color.
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