Epicuticle

From Wikipedia, the free encyclopedia

The epicuticle is the outermost portion of the exoskeleton of an insect (and various other arthropods); its exact composition and structure may differ somewhat among different taxa, but certain aspects can be generalized:

It is secreted by the epidermis, and is deposited on top of the procuticle via pores that pass outwards through the procuticle from the epidermal cells.
It contains no chitin, and is itself arranged in layers.
The layers typically consist of an inner epicuticle, an outer epicuticle (or cuticulin layer), a wax layer, and a cement layer.
The wax layer is not present in all arthropods, as its primary function is to reduce water loss.
The epicuticle cannot be digested during the molting cycle (see ecdysis), so it and the exocuticle are shed.