In cockroach water proof layer is a soft grease which is freely exposed on the surface and is largely removed by the process of adsorption that is the process by which a solid holds molecules of a gas or liquid or solute as a thin film on to the dusts.
This grease layer inhibits the transpiration or water permeability of insects and also inhibits the rate of entry of insecticides through the cuticle.
In some insects transpiration through the cuticle of insects is inhibited by a thin layer of orientated wax on the outer surface of the epicuticle and when it is heated to a certain temperature the wax layer shows an abrupt increase in permeability to water by means of scraping or wearing away of the wax layer known as abrasion.
Abrasion of the wax layer results in a great increase in transpiration through the cuticle because Inert dusts because the desiccation of insects by getting between the moving surfaces of the cuticle and abrading the wax layer.
Removal of the wax layer by means of abrasive dusts or suitable detergents increases the rate of entry of insecticides through the cuticle and also increases the transpiration or water permeability of water of the insects.
When people eat foods that contain amino acids, these amino acids make it possible for the body to create, or synthesize, proteins so if any individual do not consume some amino acids, we will not synthesize enough proteins for our bodies to function correctly.
There are nine essential amino acids such as histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine that the human body does not synthesize, so they must come from the diet. Foods that contain these nine essential acids in roughly equal proportions are called complete proteins. Complete proteins mainly come from animal sources, such as milk, meat, and eggs. Combining red beans or lentils with wholegrain rice or peanut butter with wholemeal bread also provides complete protein.
So the recommended nutrient is protein, but what a person really need is amino acids.