The molluscicidal activity of melia azadirachta on the fresh water snail physa acuta (draparnaud, 1805)‎

Abstract EN

The molluscicidal effect of Melia azadirachta was evaluated against the fresh water snail Physa acuta at juvenile freshly hatched stage to explore the potential use of this plant as a molluscicide.

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Calculating values of different concentrations (LC50 - LC90) showed that Melia azadirachta was toxic against the juvenile stage.

The use of Melia azadirchta fruit extract was considered as an effective control method for Physa acuta.

However, the appearance and expansion of the snail Physa acuta with fluctuation of the population of Lymnaea auricularia indicate that competitive exclusion might take place, depending on the susceptibility of pulmonates to Melia azadirachta toxin.

To investigate the molluscicidal activity of the alcoholic fruit extract of Melia azadirchta on Physa acuta late trochophore as an early immature stage, we used Physa acuta juvenile freshly hatched in the laboratory from samples collected during April–August (2005), and cultured in the laboratory under controlled temperature (14-15°C).

Twelve different treatment concentrations were tested, propit analysis was used for LC50 and LC90 determination, the 24-h LC50 and 48-h LC50, were 10 ppm and 4.4 ppm, respectively, and the 24-h LC90 and 48-h LC90 were 2.4 ppm and 1.4 ppm, respectively.

At high concentrations (15, 20 ppm), there were no survivals.

Activity dropped sharply after the initial exposure to the extract, heart beat dropped from 88 to 58 /minute as compared with the control (90 / min), as there was an obvious difference between 24-h LC90 and 48-h LC90.

The use of this molluscicide in minimum doses may be recommended and this may have no deleterious effects on the other co-occurrence species inhabiting the same niche.