RESUMO
Toxicity of three local formulated products, Sol E.C (mineral oil), Sisi-6 (surfactant) and Castor bean oil E.C (plant oil) were tested against Biomphalaria alexandrina and Lymnaea natalensis, in two water sources. Results indicated that in dechlorinated water after 24 hr exposure, castor bean oil was the most toxic product against the snails, followed by Sisi-6 and sol (E.C) with LC90 of 250 ppm and 8 ppm against B. alexandrina and L. natalensis, respectively. When Nile water was used after 6 hr. exposure, a high concentration of castor bean oil (4 LC90) did not achieve 100% mortality of the snails. A 100% mortality was achieved by 2 LC90 of Sisi-6 with Nile water. On the other hand, caster bean oil was more fatal to eggs of the snails (LC90=660 ppm) than the other two products. In general, L. natalensis was more susceptible to the experimental products than B. alexandrina.
