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Which insect organ releases the molting hormone ecdysone?

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Illustration showing a variety of adult insects, each labeled with its common name and order, including walkingstick, earwig, stonefly, tree cricket, dragonfly, female scale, cat flea, thrips, sucking louse, thysanuran, ant, scarab beetle, stinkbug, mosquito, and cabbage butterfly, highlighting their diverse shapes and sizes. — insect An illustration of insect diversity.

In insects, the molting hormone ecdysone is released by the prothoracic glands.123

These paired thoracic endocrine organs are stimulated to produce and release the prohormone $α$ -ecdysone after receiving signals from the prothoracicotropic hormone (PTTH), which is released from the insect's brain. Once released into the hemolymph, $α$ -ecdysone is typically converted in peripheral tissues into its active form, 20-hydroxyecdysone ( $β$ -ecdysone), which then initiates the molting process and the shedding of the old cuticle.1245