Abstract
For forecasting the appearance of the first generation adult of the peach fruit moth, Carposina niponensis WALSHINGHAM, an attempt was done to determine the termination time of diapause, by means of observating the gonads of larvae in hibernation.
During diapause, testes of larvae, consisting of four testicular chambers, are inactive and remain a definite size, and complete cysts do not yet form in the testes. The male sex-cells in diapausing larvae are in the stage just before the meiosis.
The cyst formation and the meiosis start as soon as testes begin to develop in hibernating larvae after termination of diapause. The formation of spermiodesmens occurs generally just after escape of larvae from their winter cocoon.
Between the larvae reared at Kuroishi-shi (Tsugaru district) and the larvae of Gonohe (the coast of North Pacific Ocean), there are no remarkable differences in both size and development of internal structures of testes, but considerable difference in the duration before the commencement of gonad development by incubation.
