NEW POSSIBLE MOLLUSCICIDES FROM CALENDULA MICRANTHA-OFFICINALIS AND AMMI-MAJUS .2. MOLLUSCICIDAL, PHYSIOLOGICAL, AND EGG-LAYING EFFECTS AGAINST BIOMPHALARIA-ALEXANDRINA AND BULINUS-TRUNCATUS

In the present study, the effects of CuSO4 and crude extracts of the d ifferent parts of Calendula micrantha officinalis and Ammi majus, i.e. , leaves, stems, roots, and flowers, on adult Biomphalaria alexandrina and Bulinus truncatus mere investigated, Generally, leaves and flower s of both plants exhibited marked potency in killing the snail vectors of schistosomiasis, The recorded LC(50) and LC(90) values showed that C. officinalis was more toxic to both snails than A. majus, and B. tr uncatus are more sensitive to the extracts of both plants than B. alex andrina. Snails that are produced from snails previously exposed to lo w doses were more sensitive to the tested extracts, which may give pri mary indication of no possibility of inherited resistance, Moreover, p rolonged exposure to the sublethal concentrations of A. majus have a d efinite lethal effect on the egg Laying and longevity of both snails, Also, treatment with sublethal doses of both plants clearly inhibited the transaminase activity (ALAT, ASAT), diminished the total protein c ontent, and increased markedly total lipid contents in the hemolymph o f both snails. (C) 1996 Academic Press.