The colour of Pieris wings

[Gordon Ramel]

Hi Everyone,
                    I wonder if anyone can clarify a point for me, up until
recently I had believed that the colour of the wings, particularly the white of
pierids was the result of a pigment derived from urea, however someone has
suggested that this is not so and that it is actually the result of the
physical structure of the wing scattering the light.   I would be grateful to
know what is the truth of this.

                     Yours Gratefully Gordon

        <G.J.L.Ramel at exeter.ac.uk or Gordon.Ramel at bbsrc.ac.uk>
        < http://www.ex.ac.uk/~gjlramel/welcome.html>
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