The molluscicidal activity of niclosamide (Bayluscide WP70®) on Melanoides tuberculata (Thiaridae), a snail associated with habitats of Biomphalaria glabrata (Planorbidae)

Abstract

The aim of this study was to determine the toxicity of niclosamide (Bayluscide ®) on Melanoides tuberculata and Biomphalaria glabrata under laboratory conditions. The latter species is the intermediate host of Schistosoma mansoni (Sambon 1917). M. tuberculata was successfully used as competitor of B. glabrata in biological control programs in French West Indies. Both molluscicide and biological control using M. tuberculata have proved to be successful in reducing the population density of B. glabrata. The associated use of molluscicide in this area would be an effective measure if M. tuberculata were less susceptibility to the molluscicide than B. glabrata. Three hundreds individuals each of B. glabrata and of M. tuberculata, collected in Sumidouro, State of Rio de Janeiro, were used in the experiment. The molluscs were exposed to 14 different concentrations of niclosamide as recommended by the World Health Organization. Probit analysis was used to determine the LC 50 and LC 90. The LC 50 and LC 90 values for B. glabrata were 0.077 mg/l and 0.175 mg/l, respectively and the LC 50 and LC 90 values for M. tuberculata were 0.082 mg/l and 0.221 mg/l respectively. As the lethal concentrations of niclosamide were approximately the same to both species, this could be a disadvantage when controlling B. glabrata with niclosamide in an area of M. tuberculata occurrence. It migth therefore be preferable to utilize the latex extracted from the Euphorbia splendens, which presented a much higher efficiency for B. glabrata than to M. tuberculata

Habitat preference of freshwater snails in relation to environmental factors and the presence of the competitor snail Melanoides tuberculatus (Müller, 1774)

“…may lead to a reduction of the competitive interaction between those species, thus indirectly stimulating the increase in the population of Biomphalaria spp. (Giovanelli et al 2002). On the other hand, some environmental modifications may add to the instability of the environment, what would make room for the coexistence of M. tuberculatus and Biomphalaria spp.…”

A laboratory assessment of the potential molluscicidal activity of some Nigerian plant species used as anthelmintics

“…Other tested extracts were not sufficiently molluscicidal (LC 90 values >100 mg l -1 ; 176.94-6 241.61 mg l -1 ) to warrant further investigation as plant molluscicides. Suffice to state that the susceptibility of the snails to niclosamide (positive control) was within the limits reported in the literature (Webbe 1961, Shiff et al 1970, Sarquis et al 1997, Giovanelli et al 2002.…”

Field trials of low dose Bayluscide on snail hosts of schistosome and selected non-target organisms in sahelian Cameroon

“…The differential susceptibility of aquatic organisms to Bayluscide has been used elsewhere to control nuisance organisms in the aquaculture industry (Francis-Floyd et al 1997). The live snail count registered at 24 h post application in some ponds may be related to the fact that this period is still within the 48 h recovery period reported earlier for Biomphalaria stramina in Brazil (Giovanelli et al 2002). Earlier reports of snail escape behaviour including water leaving and burrowing (Sarquis et al 1997) were not investigated, but with the relatively heavy concentration of Bayluscide that were applied on pond margins, it is not feasible that any affected snail could have escaped.…”