Effects of a Large Dose of Ecdysteroid on Development of Ovary in Bombyx Pupae

Administration of 100μg 20-hydroxyecdysone into a female Bombyx pupa at day 2 retarded its adult emergence by up to 8 days. The hormone treatment caused a significant delay in weight increase of the ovary. However, the ovary weight reached a normal level after the elongated pupal period. The animals thus treated deposited fertilized eggs, which were heavier and larger than normal eggs. These results suggest that the high dose of exogenous hormone perturbed the ovarian development, but this perturbation was compensated by the elongation of developing time of ovaries.