Microbial mosquito larvicides have gained considerable acceptance in recent years. The value of Bti, strain AM65-52 and Bs 2362, strain ABTS-1743 to mosquito-control programs worldwide is well-established. These unique strains of Bti and Bs each offer unique advantages relative to chemical insecticides, and they offer relative safety to humans and non-target organisms. Bti provides broad-spectrum activity against mosquitoes, rapid control, and low potential for resistance; while Bs exhibits extended residual control, efficacy in polluted water, and high target specificity.