Screening of some Nigerian plants for molluscicidal activity

Abstract

Methanolic (MEOH), evaporated crude water (ECW) and unevapora­ted crude water (UECW) extracts of 25 Nigerian plants, used for different medicinal and domestic purposes were screened for mollusci­cidal activity on laboratory-reared Lymnaea natalensis Krauss. Seven of the plants were not active ; extracts from 18 (72 per cent) of the plants, some of which are reknowned fish poisons, had molluscicidal acitivity. These were Acacia nilotica, Aristolochia albida, Balanites aegyptiaca, Blighia sapida, Boswellia dalzielli, Detarium microcar­ pum, Gnidia kraussiana, Kigelia africana, Nauclea latifolia, Opilia celtidefolia, Parkia clappertoniana, Polygonum limbatum, Pseudoce­ drela kotschyi, Sclerocarya birrea, Securidaca Jongipedunculata, Ximenia americana, Vetiveria nigritallJI and Ziziphus abyssinica. The LC50 of these extracts were determined. lt is strongly recommended that the toxic effects of these extracts against fish, cercariae, snail eggs and mammals be further investigated so as to determine the right concentration, especially for use in fish ponds.