Rhodnius prolixus vitellogenesis: Dependence upon the blood source

The haemolymph-protein patterns of a Rhodnius prolixus colony, fed on human blood and of a colony fed on sheep blood, were compared by SDS-PAGE analysis. The vitellogenin-polypeptide patterns of larvae and females of both colonies were similar. However, males of the human-blood-fed colony had levels of circulating vitellogenin comparable to those of females, while males of the colony fed on sheep blood had only residual vitellogenin levels. The effect of human blood on different instars of a colony fed on sheep blood was examined. Autogeny occurs in the colony fed on human blood but not on that fed on sheep blood. When 5th-instar females from the sheep-blood-fed colony were fed on human blood, the phenomenon of autogeny was not displayed after moulting to the adult stage. Fourth-instar larvae from the colony fed on sheep blood however showed autogeny in the adult stage when fed on human blood from the 4th-instar on or in this stage only. Furthermore, first-cycle oviposition and the percentage moulting to the adult stage were increased in these groups.