Development of Leishmania spp. in Mosquitoes—I. Experimental Infection of Aedes aegypti with Leishmania donovani promastigotes

In the present study, we investigated the development of Leishmania donovani promastigotes in Aedes aegypti. Infection rate in the mosquito averaged 53%. Promastigotes were limited to the hindgut where they appeared on day 4 post-infection. Massive multiplication of promastigotes occurred between 6 and 17 days post-infection. The mosquito pylorus and rectum had the highest concentration of promastigotes. A maximum life span of 20 days was observed for L. donovani promastigotes in the mosquito. Morphologically intact L. donovani promastigotes were ejected with A. aegypti faeces, following a blood meal. Implications of the development of Leishmania spp in the mosquito host are discussed.