The control of the schistosome-transmitting snail Biomphalaria glabrata by the plant Molluscicide Euphorbia splendens var. hislopii (syn milli Des. Moul): a longitudinal field study in an endemic area in Brazil

Abstract

Under laboratory conditions, latex from Euphorbia splendens has shown promise as a plant molluscicide for control of Biomphalaria species, intermediate hosts for Schistosoma mansoni. The purpose of this study was to evaluate its efficiency under field conditions. Application of filtered latex at 12 ppm to one stream in an endemic rural area in Minas Gerais state, Brazil, in September 1995, did result in a reduction in snail density as compared to an untreated stream but the snail population recovered quickly. However, two applications with a two-week interval of unfiltered E. splendens latex at 5 ppm in November 1996 in the same stream resulted in complete disappearance of B. glabrata and snails did not reappear until the 14th month after the applications. In the control stream, without treatment, the snails were found during all months. Laboratory studies confirmed that unfiltered latex is a more potent molluscicide than filtered latex. Considering the advantages of the latex such as its low toxicity to other aquatic animals and its photobiodegradability, as well as the simple method of application, this natural product is promising as an effective molluscicide.

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

“…hislopii. The latex obtained from this plant, under laboratory and field conditions, showed that it attends to queries needed to be used as a natural molluscicide (Schall et al 2001, Vasconcelllos & Amorim 2003.…”

“…hislopii. The latex obtained from this plant, under laboratory and field conditions, showed that it attends to queries needed to be used as a natural molluscicide (Schall et al 2001, Vasconcelllos & Amorim 2003.The lethal effects on the embryos in the egg masses were obtained using elevated concentrations of the latex (870 a 1500 mg/l) (Schall et al 1998), but, until the moment, there were no studies focusing the latex effects on the reproductive biology of B. glabrata.The objective of this study was evaluating the influence of sub lethal dose (LD 50 ) of latex of E. splendens var. hislopii on reproductive parameters of B. glabrata.…”

Molluscicidal action of the latex of Euphorbia splendens var. hislopii N.E.B. ("Christ's Crown") (Euphorbiaceae) against Lymnaea columella (Say, 1817) (Pulmonata: Lymnaeidae), intermediate host of Fasciola hepatica Linnaeus, 1758 (Trematode: Fasciolidae): 1- test in laboratory

“…Field studies with aqueous solutions latex were performed by Mendes et al (1992), Baptista et al (1992) and Schall et al (2001) that demonstrated 100% of mortality for Biomphalaria species.…”

Atividade moluscicida de plantas: uma alternativa profilática

“…Duas aplicações do látex não filtrado de E. splendens, em uma área rural endêmica em Minas Gerais, no intervalo de quinze dias, resultaram em 100% de mortalidade para B. glabrata (Schall et al, 2001).…”