vorticella sp: prospective mosquito biocontrol agent

background : considering the disadvantages of chemical insecticides, we aimed to evaluate vorticella parasites for control of mosquito larvae of anopheles stephensi and aedes aegypti at different larval stages. methods: vorticella sp infected mosquito larvae were crushed in the 0.85% saline and homogenized well to get vorti­cella in suspension. the effects of vorticella sp infections on larval development were investigated by inoculat­ing protozoan on different larval instars of an. stephensi and ae. aegypti and observed under light microscope. le­thal time of the vorticella infected larvae at different stages was calculated. results: first and 2 nd larval instars of both an. stephensi and ae. aegypti did not show signs of infection by vorti­cella sp., whereas 3 rd instars of an. stephensi showed more vorticella infection than those of ae. aegypti . however, 4 th larval instars of both mosquitoes were heavily infected with vorticella parasite which was responsible for slug­gish movements of larvae and eventually death. moreover, parasites ( vorticella spp) were responsible for more than 90% reduction in adult emergence for both infected an. stephensi and ae. aegypti . conclusion: this study provides insights for mosquito larvicidal action of surface parasite vorticella on different larval stages of an. stephensi and ae. aegypti . it could be suggested as a potential candidate in mosquito biocontrol programs.