Seeds of the leguminous plant Millettia thonningii were shown to possess promising molluscicidal activity against Bulinus trunctatus. The size of the snails was an important determinant of their susceptibility to the molluscicide; specimens with shell lengths of 2 to 3 mm being more susceptible than snails 5 to 6 mm long.

suspensions of ground seed material from the West African legume, Millettiu thonningii, have previously been shown to be mollusacidal to schistosome-transmitting snails and thus potentially useful as a control agent for schistosomiasis. it is demonstrated here that Millettiu seed suspensions, in addition to their molluscicidal action, show considerable toxicity towards the infective c e r d a l stage of Schistosomu mumoni, a causative agent of human intestinal schistosomiasis. This toxicity consists of a rapid knockdown effect on the cercariae, producing unresponsive immobility in times from 11 to 42min in a concentration range from 500 to 100 parts per million. Filtering reduced the speed of this effect. Cercaricidai activity of the suspensions is also demonstrated in a range of unliltered suspension concentrations, with 100% mortality occurring from I20 to 310 min after exposure. This potent action will add to the potential effectiveness of a Millettiu molluscicide preparation when used as a control agent for schistosomiasis.

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