Living With Reflective Colors

Golden Tortoise Beetles on sweet potato leaf

Insects can produce conspicuous colors with reflected light. If light is reflected in a narrow band, as in Morpho Butterflies, it will produce a color in the wavelength reflected. The wavelengths reflected are a product of microscopic ridges on the wing scales. A multilayered reflective surface that lacks the grooves, but consists of layers of varying thickness will be a broadband reflector. That is: Broadband reflectors reflect light of multiple wavelengths. The broader the range of wavelengths reflected, the closer the color approaches pure gold.

The Golden Tortoise beetles, Charidotella sexpunctata, have chitin multilayers in their elytra (wing covers) that serve as broadband reflectors when they are hydrated. Living beetles are a beautiful gold color. Unfortunately, the gold color disappears after they die and dehydrate. The beetles lose their gold color once they are collected.

About jjneal

Jonathan Neal is an Associate Professor of Entomology at Purdue University and author of the textbook, Living With Insects (2010). This blog is a forum to communicate about the intersection of insects with people and policy. This is a personal blog. The opinions and materials posted here are those of the author and are in no way connected with those of my employer.
This entry was posted in Biomaterials, by jjneal. Bookmark the permalink.

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