抄録
It was Previously reported (1972) that the injection of solutions of metal ions into brainless diapausing silkworm pupae leads to emergence of the imago, with high incidence in test Bombyx and with low incidence in test Samia.In the present experiments, there was no false-positive case in either Bombyx or Samia after the injection of non-hormonal agents into isolated pupal abdomens.Comparative experiments on isolated pupal abdomen, brainless pupa, and transected brainless pupa led to the conclusion that certain isolations act directly on the prothoracic gland to induce secrection of ecdysone.Injection of aqueous solutions of the organic solvents; acetone, ethyl alcohol, ethyl acetate, and ether brought about emergence of brainless Samia pupae in some cases, but only when the solvents were injected in very high concentration. The emerged specimens in most of these cases showed an absence of gonadal development.