Involved in the inactivation of ecdysteroid molting hormones by converting ecdysteroids into 3-dehydroecdysteroids. ecdysone + O2 = 3-dehydroecdysone + H2O2 Expressed in the midgut at the prepupal stage of the last larval instar. Induced by RH-5992, which is an ecdysone agonist used as insecticide. Belongs to the GMC oxidoreductase family.