how does camouflage help an insect?

Camouflage may be defined as some set of methods adopted by the organism in order to hide or protect itself from its environment. These methods may include change in color, body shape or behavior of the organism in order to resemble with the surrounding environment. 

Camouflage helps the insects to protect themselves from the predators. They make themselves resemble to the surrounding so that the predators cannot notice them. For example a monarch butterfly is a very bad tasting insect for the birds having orange-black patterned wing, so the viceroy butterfly makes itself resemble to the monarch butterfly protecting itself from the prey. Also many harmless insects resemble themselves to insects which can sting in order to protect themselves.