1. This article dealt with the effect of artificial shortening and prolongation of the period of Anthetaea pernyi pupae upon the emergence of the adult, and the development of the larva, the voltinism and the characteristics of cocoon (namely; cocooning the weight of cocoon and cocoon layers) in the secondary generation.
2. The first emergence of the adult either of univoltine or bivoltine brood begins after elaps of 19 to 26 days by keeping the pupa under the condition of temperature (20°to 21°C) from December 10th. The period and the duration of emergence are shortened by keeping the pupa in the above described temperature later (January 27 th.) than earlier date (Jan. 10 th.) by which the dormancy of the pupa is easily broken. The percentage of emerging moth is not affected by the length of hibernation term.
b) It can be seen visibly that the univoltine brood pupae require longer time before the begining of adult appearance and the percentage of emerging moth is so larger than those of bivoltine brood.
The duration of emerging out perfectly in both blood is similar.
3. By artificial prolongation of the hibernating period, the effect is summarised on the following topics.
a) The duration between the emergence of the adult and the hatching of the larva is shortened and the percentage of emerging moth became less. The duration of emergence and number of deposited egg is normal.
b) The secondary larval stage is shortened.
c) The ratio of good cocoons is reduced, the weight of cocoon, cocoon layer and the ratio of cocoon layer are increased.
d) The percentage of hibernating pupae in secondary generation is increased.