The hormonal control of vitellogenin synthesis in the fat body of the female Colorado potato beetle.

Vitellogenin synthesis in the fat body of the female Colorado potato beetle is affected by juvenile hormone (JH) as was demonstrated by its stimulation after topical application of 50 μg JH to allatocardiacectomized prediapause females. The peak of vitellogenin synthesis is reached 5 days after the administration of JH. Allatocardiacectomy in 5-day-old long-day females does not result in decreased rates of vitellogenin synthesis in comparison with the sham-operated control insects. In postdiapausing long-day females which are allatocardiacectomized during diapause, vitellogenin synthesis increases in the absence of JH. It is concluded, therefore, that factors other than JH are involved. β-Ecdysone does not seem to participate in the regulation of vitellogenin synthesis. In virgin long-day females (12 days after adult ecdysis) JH synthesis and protein synthesis are as high as in mated females, although a virgin produces one-sixth the amount of eggs. In the virgin female the rate of vitellogenin synthesis is uncoupled from the rate of egg laying; this suggests a rather autonomous role in the accumulation of proteins by the ovary.