Hormonal control of insect development

Fig. I. Hormonal control of insect development. Three hormones are involved the brain hormone, acting on the prothoracic glands, the juvenile hormone, secreted by the corpora allata and ecdysone, secreted by the prothoracic glands. The bottom row shows the development from the caterpillar through the pupa to the moth. The larval ecdyses are controlled by ecdysone and juvenile hormone, but the pupal and imaginal ecdyses are induced only by ecdysone. (from P. Karlson, Lehrbuch der Biochemie, with kind permission of G. Thicme Verlag, Stuttgart.)...

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