I’ve had the chance to observe some interesting organisms and structures with my Foldscope thus far and my new favorite subject is the butterfly wing. 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 their colors. Their color arises due to the nature of the scales that 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. Viewed with Foldscope 140X.

A compilation of butterflies I’ve sampled with the Foldscope in the Neotropics (wings to left and Foldscope image of respective wing to the right). See if you can figure out which are caused by pigmentation and which are caused by structural color.

Red wings likely due to pigment production. Pigments typically create “hot” colors from red to yellow.

Structural colors from physical phenomena usually produce “cold” colors from near ultraviolet to blue-green.

Manu brought up an interesting question online the other day – can the Foldscope community produce a “library” of butterfly wing scales? That would be a very interesting community project and may provide insight and perspective by comparing scale structure morphology across a broad range of species.

A slide of a moth wing which can then be placed under the Foldscope.

The result – scale structure & colors can be resolved quite nicely at 140X.

Wings can also be pressed to a piece of tape and the scales will remain stuck in place.

Hope you enjoyed, let me know your thoughts on colors, physics & butterflies!

-Aaron