Fig. 4.

Diffraction signatures showing the cuticles’ capability of scattering light to larger polar angles. (A) Schematics illustrating the spatial distribution of light reflected from the beetle’s cuticle, which is a function of the polar angle $\theta$ and azimuthal angle $\phi$. (B) Measured diffraction microscopy images for the red and green beetles. The main and the inset diffraction images are collected using an imaging scatterometer with illumination spots of diameter 200 µm and 5 µm, respectively. (C) Schematic illustrating how deviating diffraction efficiency to a larger polar angle could reduce detection by predators and benefit intraspecies communication.