prothoracic glands
From ZooTerms (Dictionary of Invertebrate Zoology)
prothoracic glands also ventral glands: (Arthropoda: Insecta) Specialized endocrine glands of larvae consisting of a pair of diffused glands at the back of the head, the thorax, or at the base of the labium producing the molting hormone (ecdysone); usually breakdown after the final molt; thoracic glands; pericardial glands; ecdysial glands.
