Conversion of carbaryl at the site of larval tissues of the silkworm, Bombyx mori L. (lepidoptera: bombycidae)

^ C-Carbaryl administered orally was quickly distributed in all tissues and converted into a hydroxy-metabolite, 2-hydroxy 1-naphthyl N-methylcarbamate. The metabolism of carbaryl was essentially similar at both high and low doses. Two radioactive peaks were observed in the tissues after treatment with the insecticide; the first peak corresponded to the carbaryl initially taken up and the second peak was recognized as its major matabolite. The rate of disappearance of carbaryl and of the formation of its metabolites differed according to the dose of the insecticide. The fat body formed more quickly the hydroxymetabolite than other tissues. In the case of larvae treated with a non-lethal dose, the time of recovery from toxic symptoms coincided with that of the disappearance of carbaryl from the tissues.At this time, the major metabolite reached maximum levels.