Manifestation of Characteristics in the Giant Egg “Mutant of Bombyx mori (Lepidoptera: Bombycidae). 2. Artificial Induction of Large Eggs by Application of Large Amounts of 20-hydroxyecdysone.”

Injection of large amounts of 20-hydroxyecdysone into normal female pupae of Bombyx mori altered egg production. Large eggs were produced in addition to normal eggs. 1) These eggs were as large and heavy as Ge mutant eggs. 2) Yolk protein contents in these large eggs had almost the same values as those of Ge eggs. However, there is no qualitative difference in the protein patterns of 20-hydroxyecdysone induced large eggs and normal eggs. 3) Large eggs were induced by injection of 20-hydroxyecdysone at doses of more than 50 μg. 4) Induction of large eggs was achieved at the expense of the total number of eggs, similarly to the case of Ge mutants. 5) Distribution of the enlarged eggs in a ovariole was not at random, but clustered in definite regions.