Efficacy of Achyranthes aspera (L.) as a Molluscicidal Bait Formulation against Fresh Water Snail Biomphalaria pfeifferi

Molluscicidal plant products have interesting attributes of environmental friendliness and accessibility to local communities. Their bait formulations are more economical and target specific as they are applied only to the snail-infested sections of the water habitat. Their active ingestion by target snails could also increase gastric concentrations and enhance effectiveness. This study aimed to evaluate the comparative effectiveness of Achyranthes aspera (A. aspera) leaf hydroethanolic extract in bait and immersion applications. Serial dilutions of the extract in water for immersion, and in snail food pellets for bait test, were set. Adult Biomphalaria pfeifferi snails exposed to the bioassays for 24 hours and data were analyzed using probit model. The plant showed molluscicidal activity in both methods. The respective LC(50) and LC(90) doses were 20.37 and 46.84 ppm in the immersion and 3.10 and 11.08 ppm in the bait. The more efficient bait method reduced the LC(50) by 6.57 and the LC(90) by 4.23 times. This finding provides a strong foundation for the molluscicidal potential of A. aspera. It is applicable and possibly more effective if formulated into those commercially available snail food pellets or flakes. However, selection and optimization of suitable baits is a crucial step for maximum output.