Field trials of low dose Bayluscide on snail hosts of schistosome and selected non-target organisms in sahelian Cameroon

More than 85 percent of all cases of schistosomiasis in Cameroon occur in the northern sahelian half of the country representing 20 percent of the population. Several workers have advocated the integrated approach to schistosomiasis control, including snail control, but the death and decay of aquatic organisms, and fish kill that often follows Bayluscide application at the dose of 1g/m³ decrease its acceptability. The present study was designed to assess the effect of lower Bayluscide doses on snail host and non-target fish, frog, the tadpole kill. Bayluscide was applied to study ponds at concentrations of 0, 0.25, 0.5, and 1 g/m³ (ppm). Pre and post application assessment of snails hosts of schistosomes, fish, frog, and tadpole kill were carried out. All 0.25, 0.5, and 1 g/m³ Bayluscide concentrations reduced snail population significantly. Bayluscide concentration of 0.50 g/m³ applied in two rounds of 0.25 g/m³ resulted in high snail mortality and low lethality to fish, frogs, and tadpoles. Further studies are needed to assess the cost-effectiveness of Bayluscide in the control of schistosomiasis following the simplified approach.

Phytochemical and molluscicidal properties of buddelia madgascariensis

Phytochemical screening of leaves, stems and flowers of Buddleia madgascariensis [Loganiaceae] revealed the presence of sterols and/or triterpenes, carbohydrates and/or glycosides, flavonoids, tannins as well as alkaloids and/or nitrogenous bases in all organs, whereas saponins were found in leaves and stems only. Molluscicidal tests of aqueous suspension of plant leaves, stems and flowers against the two aquatic snails [Bulinus truncatus and Lymnaea cailliaudi] exhibited that the leaves have strong activity [LC90 were 75 and 70 ppm] against the two snail species within 24 hours, respectively. Also, the LC90 of different extracts of the leaves against B. truncates showed that the methanol extract is the most active one [LC90 = 40 ppm]. The effect of some environmental conditions on the molluscicidal activity of leaves water suspension of the tested plant was determined