Nanoscale cuticle mass density variations influenced by pigmentation in butterfly wing scales Nature Communications - Here, the authors investigate the interaction of pigment distribution and cuticle density within butterfly wing scales. They use ptychographic X-ray computed tomography to...

Here is a very detailed examination on how pigmentation in the cuticle of a butterfly wing scale changes the density and refractive index of chitin and, thus, also alters structural color. rdcu.be/eyUwS

A novel Hox gene promoter fuels the evolution of adaptive phenotypic plasticity Adaptive phenotypic plasticity allows organisms to display distinct phenotypes in response to variable environments, but little is known about the genomic changes that promote the evolution of plastic...

For those interested in the evolution of phenotypic plasticity - Shen Tian et al. found that a novel bit of DNA - a Hox gene promoter in the genome of satyrid butterflies - boosts plasticity in the size of their eyespots in response to temperature.
www.biorxiv.org/content/10.1...