Brousing today's science news turned up a bit of research on the
self-cleaning properties of titanium dioxide - a pigment used in
'superwhite' paints.

From a Science Daily story on self-cleaning bathrooms:

"The particles work by absorbing ultraviolet light below a certain
wavelength, exciting electrons and giving the particles an oxidising quality
stronger than any commercial bleach."
"These nanoparticles then kill microbes and break down organic compounds.
And because surfaces coated with titanium dioxide have another property
called 'superhydrophilicity' -- meaning droplets do not form -- water runs
straight off the surface, washing as it goes."

Now, highly oxidizing properties doesn't sound to great when applied
directly to epoxy/carbon structure but it might be possible to build up
layers that would get the bug cleaning properties of titanium dioxide on the
surface and still protect the underlying structure.

Just thinking outside the box.

Bill Daniels