If an insect does not have wings how does that help the insect?

Answer 1

Flying insects are one of three members of a group known as hexapoda (literally, six walking appendages). True winged insects do have wings as adults. Every one of them. Two pairs of them, in fact. Sometimes the top pair hardens and becomes a protective shell for the insect and the lower pair of wings (beetles), sometimes the lower pair becomes nothing more than a vestigial, and is only used to stabilise flight (bees and some flies), sometimes both pairs of wings are developed for warning against predators and for courtship displays (butterflies and moths). A class called parainsecta (of which silverfish and firebrats are members) has all the characteristics of flying insects apart from the wings. The question of whether an animal has wings or not is entirely down to evolutionary necessity.