Apochiton

Apochiton is a rarely used term in entomology, specifically referring to the cast-off exuviae, or shed skin, of an insect after molting. More commonly, the term "exuviae" is used to describe this cast skin. Apochiton encompasses all the layers of the exoskeleton that are discarded during the molting process, including the epicuticle, exocuticle, and endocuticle, although the endocuticle may be largely reabsorbed before ecdysis (the actual shedding of the skin). The composition of the apochiton is primarily chitin, along with proteins, lipids, and sometimes pigments. It provides a record of the insect's form and size at a particular stage of development and can sometimes be used for identification purposes, though this is less reliable than examining the living insect. The term may also less frequently refer to discarded exoskeletal material of other arthropods beyond insects.