Abstract
In order to analyze the endocrine system involved in control of oogenesis in the housefly, Musca domestica vicina Macquart, the function of corpus allatum was investigated with special reference to the action of juvenile hormone. After emergence of female fly, the size of corpus allatum increased and attained to the maximum size at the vitellogenic stage. When newly emerged flies were decapitated or starved, both corpus allatum enlargement and follicle growth were inhibited conspicuously. Follicle growth was also inhibited in allatectomized one. These results imply the function of corpus allatum involved in control of housefly oogenesis (Fig. 1). Allatectomized flies were topically applied with juvenile hormone analogue, methoprene (ALTOSID, ZR-515) and the effect on follicle growth was examined. Ovarian development of allatectomized one was stimulated distinctly with methoprene, and all the individuals treated showed ovarian maturation at the dose of 0.25μg (Table 1). Consequently it was proved out that juvenile hormone was a primary stimulus to regulate housefly oogenesis. As a next step of the experiment, influence of juvenile hormone on both processes of oogenesis-initiation and vitellogenesis was investigated. Growth of juvenile follicles in starved- and decapitated-flies was remarkably stimulated with methoprene (Fig. 2). Furthermore, methoprene stimulated markedly the vitellogenesis of normal-, allatectomized- and decapitated-flies which were fed on 10% sugar solution (Fig. 3). Thus juvenile hormone was shown to possess gonadotrophic as well as vitellogenic activity in the housefly.
