Molluscicidal effects of endod (<i>Phytolacca dodecandra</i>) on fasciola transmitting snails

Abstract

A study was conducted to investigate the molluscicidal effects of crude water suspension of unripe green Endod (Phytolacca dodecandra) berries (Type 44) on different developmental stages of Lymnaea natalensis and Lymnaea truncatula. Concentration of 20 ppm for exposure period of 24 hours induced 100 % mortality in young L. natalensis and L. truncatula snails, while higher concentration was required for mature snails of both species. The LC90 on L. natalensis with shell height of 5-9.8 mm., 10–2.9 mm. and 13–18.5 mm. was 19.8, 21.1, 22.8 ppm, respectively. With regards to L. truncatula the LC90 for snails with a shell height of 3.4-5.4 mm and 5.7–8.2 mm was 19.5 and 21 ppm, respectively. Study on time-concentration relationship revealed that exposing snails for one hour required a concentration of 48.9 and 72.5 ppm in young (6–12.4 mm.) and adult (12.5–18.5 mm.) L. natalensis to cause 90% mortality, respectively. In the case of L. truncatula snails (4.5–7.4 mm) 54.5 ppm was needed to produce 90 % mortality. However, both snail species were killed at about a concentration of 20 ppm between 6 and 24 hours of exposure times.


Key words/phrases: Endod, fascioliasis, Lymnaea natalensis, Lymnaea truncatula, Molluscicide


SINET: Ethiopian Journal of Science Vol.25(2) 2002: 275-284