Moreover, as we shall see, evidence has accumulated to show that this hormone brings about suppression of adult characters by favouring the differentiation of larval characters. It has therefore been called fore preference the 'juvenile hormone'. If a Greek term is preferred it might be called 'neotenin'.
Source: wiktionary
Neotenin, also known as the juvenile hormone, is secreted by the corpora allata.
Source: wiktionary
“Bound” neotenin should be readily “given up” to “acceptor” molecules, but the authors found evidence that it was to a considerable degree protected from attack by neotenin-specific esterases in the haemolymph; it was surmised that such proteins might play an important part in regulating the action of the hormone.
Source: wiktionary