RESUMEN
The present study was designed to investigate Frenkania hirsuta and Withania somnifera as molluscicides of plant origin against Biomphalaria alexandrina snails. Bait formulations technique was used in this study in order to produce a considerable reduction of these molluscan hosts with minimal adverse effect on the environment. Efficacy of the prepared bait and behavioral responses of snails towards these formulations were studied by using clear plastic container bioassay. Their effect on fecundity and hatchability of snail's eggs were also investigated. Moreover, the effect of these bait formulations on some biochemical parameters [DNA, RNA, Proteins and Fatty acids] of snail's haemolymph was elucidated. The results revealed that both Frenkania hirsuta and Withania somnifera caused disturbances in the chemical structure of nucleic acids, proteins and fatty acids, besides being toxic to the snail hosts. This also, influenced the spread of these hosts as reflected by the changes in snail reproduction rates