  We probe the natural complex structures in the transparent insect wings by a
simple, non-invasive, real time optical technique using both monochromatic and
broadband femtosecond lasers. A stable, reproducible and novel diffraction
pattern is observed unveiling long range spatial correlations and
structural-symmetry at various length scales for a large variety of wings.
While matching the sensitivity of SEM for such microstructures, it is highly
efficient for extracting long range structural organization with potentially
broad applicability.
