THE ROLE OF JUVENILE-HORMONE IN VITELLOGENIN PRODUCTION IN RHODNIUS-PROLIXUS

Following feeding in adult females of Rhodnius prolixus, vitellogenin titres in the haemolymph, as determined by rocket immuno-electrophoresis, reach a higher level in mated females than in virgins. Allatectomy early in adult life decreases, but does not entirely abolish, vitellogenin levels in the haemolymph of fed females, confirming that juvenile hormone is not an absolute requirement for vitellogenin synthesis in this species. Topical application of 100 ng of juvenile hormone to allatectomized females restores the titre of vitellogenin in the haemolymph to normal levels, but fails to stimulate vitellin accumulation in the ovary. Treatment with 100 mug restores both vitellogenin and vitellin levels to normal. This is interpreted as being due to a differential sensitivity to juvenile hormone of the mechanisms governing synthesis and uptake.