ABSTRACT
Perhaps as many as 300 million human beings are victims of snail-borne parasitic diseases: schistosomiasis, fasciolopsis, angiostrongyliasis, clonorchiasis, and paragonimiasis. Parasitic-disease control can emphasize prevention of infection or chemotherapy after infection. In practice, public health authorities have relied almost exclusively on chemical control strategies. Molluscicides are applied through various techniques to the water course as granules, wettable powders, solutions, or emulsions. The development of controlled-release molluscicides was a logical extension of the antifouling rubber program of the B. F. Goodrich Company,. Controlled-release formulations based upon the use of elastomers or plastics as the binding matrix can be processed in geometries most conducive to pest control in a specific habitat. Laboratory and small-scale field evaluations have demonstrated that candidate controlled-release molluscicides are efficacious under varying environmental conditions. Usage of controlled-release molluscicide will necessitate the development and evaluation of a methodology substantially different from the conventional.
