The life-cycle of Leishmania in the sandfly with special reference to the form infective to the vertebrate host.

A review is given of recent advances in studies on the life-cycles of leishmaniae in phlebotomine sandflies including observations on the morphology and attachment of the parasites, putative genetic exchange in Leishmania, newly found factors affecting the development of the parasite in the fly, and the characteristics of metacyclic promastigotes related to their preadaptation for life in the vertebrate host.