Juvenile Hormone Metabolism in the American Cockroach, Periplaneta americana, (L.)

Abstract

his study confirms the results of Slade and Zibitt, (1972), and Ajami and Riddiford, (1973), that juvenile hormone in insects is predominately metabolized by esterase attack at the methyl ester as well as by epoxide hydration. We were unable however to find the JH acid – diol metabolite present in any of our extracts. Many esterases were found in the hemolymph, gut, and fat body of male nymphs of Periplaneta americana, with the fat body containing these enzymes in greater abundance than the other tissues. Tracing experiments carried out on last instar male nymphs show significant amounts of label present in the gut and excrement after six hours. We were unable to show any evidence of binding of juvenile hormone in last instar male nymphs. It appears that on a wet weight of tissue basis, that last instar nymphs possess a greater ability to degrade 3H - Cecropia juvenile hormone to JH – acid than younger nymphs.