ENT378 Lecture 3: Integument

• School: University of Alberta
• Department: Entomology (Biological Sciences)
• Course: ENT378
• Professor: Andrew Keddie

Document Summary

All insects have a stiffened chitinous exoskeleton. Function: physical protection, muscle attachment, reduction of water loss, excretion of nitrogenous waste (for those without malphigian tubules), metabolite reserve for recycling of new integuments or starvation, protects against pathogens, and pigmentation of the insect. The integument is layered (from outside to in): epicuticle, cuticulin, procuticle, epidermis, The epidermis is a single cell layer found at the base of the exoskeleton. (basal lamina is basal lamina. the lowest layer) Parasitic wasps use melanisation process to seal the exoskeleton from bleeding. The cuticle is an acellular layer largely of homopolysaccharides above the epidermis: epicuticle: mature piece of cuticle, dynamic, very thin (microns), function: water retention made up of waxes, and cement. It has a ring structure and is synthesized from trehalose. Nag is analogous to molecules food in wood fibers. Binding site is available to form covalent bonds between antiparallel layers (branching).