Need scale information

[Neil Jones]

In article <evoluhol-2608981314430001 at pm3184.spectra.net>
           evoluhol at magnum.wpe.com  writes:

> A book on irridescence in nature describes scales on wings like Morpho as
> each one being somewhat transparent but each one being "christmas" tree in
> shape.
> 
> Most butterfly color is actually pigment.  Did I read somewhere that
> yellows come from residual urea in the caterpillar?
> 
> Dave

The actual starting point in the metabolic pathway differs depending
on the class of pigment. The pterins producing whites and yellows
in the Pierids are derived from Guanosine triphosphate.
The Omochromes in the Nymphalids are derived from Tryptophan
and the Flavonoids which occur in many species are derived from
the Larval foodplant.

-- 
Neil Jones- Neil at nwjones.demon.co.uk http://www.nwjones.demon.co.uk/
"At some point I had to stand up and be counted. Who speaks for the
butterflies?" Andrew Lees - The quotation on his memorial at Crymlyn Bog
National Nature Reserve