O uso da casca da castanha do caju, Anacardium occidentale, como moluscicida alternativo

Abstract

Bioensaios usando extratos hexânicos de cascas da castanha do caju, Anacardium occidentale, coletadas no Ceará em 1972 (amostra 1) e em 1987 (amostra 2) foram feitos sobre moluscos adultos e desovas de Biomphalaria glabrata, B. tenagophila e B. straminea, no laboratório e no campo. As cascas, 18,5 g, sem triturar amostra 1, também foram testadas sobre moluscos adultos e desovas das três espécies. A toxidez do extrato foi testada ainda sobre peixes (Poecilia reticulata) e girinos. As concentrações letais CL90, amostra 1, foram de 2,0 a 2,2 ppm para os moluscos das três espécies. Para B. glabrata adultos, recém-eclodidos e desovas as CL90, amostra 2, foram de 2,0, 0,5 e 30,0 ppm respectivamente. As cascas causaram mortalidade de 40 a 80% dos moluscos e de 22 a 35% dos embriões, ocasionando redução de 40 a 55% na oviposição das três espécies. O extrato hexânico, amostra 2, foi inócuo para girinos e peixes até 2 ppm. No campo, em poços com água parada, tratados com 20 ppm do extrato, amostra 1, ocorreu 97,1% de mortalidade de B. straminea e 100% de B. glabrata e B. tenagophila. Com a niclosamida a 3 ppm ocorreu 100% de mortalidade das três espécies.

Preliminary phytochemical screening and molluscicidal activity of the aqueous extract of Bidens pilosa Linné (Asteraceae) in Subulina octona (Mollusca, Subulinidade)

“…These results demonstrate that there is a difference in the snail response to the molluscicide according to the life stage. Souza et al (1992) verified more sensibility of newly hatched B. glabrata to the extract of Anacardium occidentale (Anacardiaceae). Nascimento (2006) verified molluscicidal activity of extracts of Allamanda cathartica L. (Apocynaceae) in newly hatched Bradybaena similaris (Férussac 1821) (Bradybaenidae) while in adults was only checked the repellent action.…”

“…The ineffectiveness of some extracts in snails eggs have been questioned by some authors (Leyton et al 2005, Magalhães et al 2003, Souza et al 1992. According to Lemma and yau (1974), the low efficiency of molluscicides in eggs is probably due to their high molecular weights that hinder the passing of the molluscicides trough the membrane that involves the egg.…”

Phytochemical and molluscicidal activity of Mikania glomerata Sprengel (Asteraceae) in different lifestages of Subulina octona (Mollusca, Subulinidade)

“…The low hatching rates are important for the control of snails because if the number of hatched snails is low, the lower would be the adult population with reproductive potential. The inactiveness of some extracts in snails eggs have been questioned by some authors (Pereira et al 1978;Souza et al 1992;Magalhães 2003;Leyton et al 2005). According to Lemma and Yau (1974), the low efficiency of molluscicides in eggs is probably due to their high molecular weights that hinder the passing of the molluscicides through the membrane that the egg has.…”

Reproductive activity alterations on the Biomphalaria glabrata exposed to Euphorbia splendens var. hislopii latex

“…Many natural products have been used in high concentrations, interfering with different reproductive parameters (Schall et al 1992, 1998, Souza et al 1992, Mantawy 2001, Bacchetta et al 2002, Tantawy 2002. But, by the first time it was showed that the concentration of E. splendens var.…”