The metabolism of ingested and injected [ ³ H]ecdysone by final instar larvae of <i>Heliothis armigera</i>

Abstract

ABSTRACT. When larvae of Heliothis armigera (Hüber) are fed on a diet containing [ 3 H]ecdysone they produce large quantities of ecdysone 22‐palmitate, probably in the gut. The radiolabel is excreted in the faeces chiefly as ecdysone 22‐palmitate, but appreciable quantities of unchanged ecdysone are also found together with traces of ecdysone 2‐and 3‐acetates. No polar metabolites are found with ingested ecdysone, and the ecdysone probably did not penetrate the gut wall, since on injection into the body, ecdysone was appreciably converted into polar metabolites.