During premetamorphosis, hypothalamus is immature. Metamorphic climax results from high T 3 and T 4 and low prolactin levels. Negative feedback loop begins. A. Hemimetabolous vs. holometabolous development. Undergo incomplete metamorphosis.
Young nymph resemble adults in appearance and diet.
Goes through a series of molts, finally emerging as adult 2. Undergo complete metamorphosis. Larvae do not resemble adults. Undergo a series of molts , increasing in size at each instar . B. Stages represent different functional periods.