Environmental impacts on the insect exoskeleton

Over 80% of animal species rely on exoskeletal cuticle for body stabilization and protection from the environment, including predators, conspecifics, and pathogens. Therefore, the exoskeleton should be thick and robust; insects with thin cuticles are likely to be more vulnerable to injuries, desiccation, pathogens, and insecticides, and are less likely to survive attacks by predators. Aside from internal processes that influence cuticle deposition, environmental factors can have large effects on the rate and quantity of cuticle deposited during juvenile and adult stages. However, we currently lack a comprehensive understanding of the various environmental factors that shape cuticle development. We therefore provide an overview of the existing literature on key environmental factors including temperature, diet, and insecticides, that shape insect cuticle deposition and overall robustness. By synthesizing empirical evidence examining the relationship between these environmental factors and cuticle thickness, we identify broad, generalizable patterns across taxa and identify exciting, clear paths for future research.