VITELLOGENESIS IN THE STICK INSECT BACILLUS ROSSIUS (ROSSI) (PHASMATODEA BACILLIDAE)

SUMMARY In this work we have attempted to clarify how vitellogenic development is regulated in the stick insect Bacillus rossius (Rossi) (Insecta Phasmatodea Bacillidae). To accomplish this end, ovarian follicles were dissected from adult females and examined ultrastructurally and biochemically after in vivo and in vitro exposures to radioactive amino acids. The data presented here are consonant with the hypothesis that transition from the subterminal to the terminal position in the ovariole is mainly due to the acquisition of vitellogenic competence by the developing follicle. This in all likelihood attained by a restructuring of the follicle cell/oocyte interface without apparently involving a shift in the synthetic patterns of the developing follicle.