Nanoindentation to quantify the effect of insect dimorphism on the mechanical properties of insect rubberlike cuticle

Rubberlike insect cuticle is a light fibrous composite, which exhibits great deformability and long-range elasticity due to the presence of a large amount of the elastomeric protein resilin. The presence of resilin in specific locations in the insect body leads to the assumption that its main function is loss-free storage of energy. Rubberlike cuticle was identified, for the first time, in the femur base of the sand field cricket, Gryllus firmus, using fluorescence microscopy and various staining methods. Dynamic nanoindentation testing was then used to investigate the differences in the mechanical properties of rubberlike cuticle between males and females and wing morphs of this species. Significant changes in storage, loss moduli, and resilience were captured between female wing morphs. The results provide insight into the structure-function relations associated with the properties of insect joints from different morphs and genders.