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A new endocrine function has been shown to play a role in insect morphogenesis. The hormone named proctodone is secreted by specialized cells of the hindgut and appears to affect the brain, resulting in the activation of the brain hormone-producing system. Proctodone has been found in two lepidopterous species-Ostrinia nubilalis and Galleria mellonella. In the O. nubilalis, proctodone plays a part in both photoperiodism and diapause.
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Beck et al. (1964) studied this question.
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