RESUMEN
The toxicity of three local formulated products [Sol EC [mineral oil], Sisi-6 [surfactant] and castor bean oil EC [plant oil]] was tested against Biomphalaria alexandrina and Lymnaea natalensis in two water sources. The results indicated that in dechlorinated water after 24-hour exposure, castor bean oil was the most toxic product against the snails, followed by Sisi-6 and Sol [EC] with LC90 of 250 ppm and 8 ppm against B. alexandrina and L. natalensis, respectively. When Nile water was used after 6-hour exposure, a high concentration of castor bean oil [4 LC90] did not cause 100% mortality of the snails; it was achieved by 2 LC90 of Sisi-6 with Nile water. On the other hand, castor 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