Abstract
The male pupae at the various stages were treated for 24, 48 and 72 hours with high temperature (38°C). The marked effects were observed in the apyrene spermatozoa, while the eupyrene spermatozoa were slightly affected. In the groups treated for 48 hours within 48 hours and for 72 hours within 120 hours after pupation, a large number of apyrene sperm bundles of abnormal shape appeared in the testicular follicle. Markedly shrunken apyrene spermatozoa appeared in the seminal vesicle of the males by the treatment for 24 hours at 144 hours after pupation and for 48 hours at 48 hours and at 144 hours. The treatment for 72 hours caused the same abnormal apyrene spermatozoa in all the groups. When such abnormal males, in which the markedly shrunken spermatozoa were observed, mated with normal females, the females of which a part of eupyrene sperm bundles were not separated in the copulatory pouch and no spermatozoa were found in the seminal receptacle were often obtained. When the observation mentioned above and the percentage of unfertilized eggs studied in the previous paper were considered together, it was suggested that abnormality of apyrene spermatozoa in the seminal vesicle was closely related to male sterility.
