h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Although most iridescence in insects does result from surface structure, that should not be construed to mean that insects do not produce pigment nor that all colour results from surface structure. Perhaps the most famous insect pigment is cochineal, a red dye that has been in use in Mexico since before Europeans arrived. It's used to color ruby red grapefruit juice, among other things, in modern society. Butterfly wings look the way they do because of a combination of pigment and surface structure. You can actually rub that pigment off on your fingers if you touch butterfly wings.

I don't dispute the main point here (that insects have pigment) but what you rub off if you touch a butterfly (or moth) wing are scales (pigmented scales admittedly) and not just pigment as you suggest.

Hmm, I only intented for this article to be a short overview, hence the title, I know I left a lot out and made some very broad generalisations. However I guess a slight change to that sentance could be benificial. I'll give it some thought