Also known as incomplete or simple metamorphosis. Insects that undergo hemimetabolous metamorphosis emerge from eggs into nymphs (called larvae by some entomologists) that are similar in shape to the adults. They go through several nymphal stages (called instars) before they undergo a final molt into their adult form. You can distinguish the nymphs from the adults by looking for wings. With one exception (mayflies), only the mature, adult stages of insects have fully developed wings. Wingbuds or wingpads may be present in late stage nymphs, but they are fixed in place against the body and are non-functional.