Abstract:

    Molluscicidal activity of different solvent extracts (i.e. chloroform, carbon tetrachloride, diethyl ether, ethyl alcohol and acetone) of leaf and bark of Euphorbia hirta plant (Family: Euphorbiaceae) against freshwater vector snails Lymnaea acuminata and Indoplanorbis exustus have been reported. Both the snails are intermediate host of Fasciola hepatica and Fasciola gigantica, which causes endemic fascioliasis in cattle and livestock of Northern part of India. Toxicity of all the solvent extracts of both the plant parts was time and dose dependent against both the vector snails. There was significant negative correlation between LC values and exposure periods. Thus, the LC50 value of chloroform extract of Euphorbia hirta leaf were decrease from 52.63 mg/L (24h) to 24.10 mg/L (96); carbon tetrachloride extract were decrease from 52.74 mg/L (24h) to 25.18 mg/L (96h); diethyl ether extract were decrease from 52.92 mg/L (24h) to 24.51 mg/L (96h); ethyl alcohol extract were decrease from 54.24 mg/L (24h) to 27.69 mg/L (96h) and acetone extract were decrease from 55.17 mg/L (24h) to 28.12 mg/L (96h), respectively against vector snail Lymnaea acuminata. Similar trend of toxicity was observed in case of vector snail Indoplanorbis exustus. Similar trend of toxicity was also observed in case of bark extracts of Euphorbia hirta plant of all the solvent extracts against both the vector snails.
    Twenty four hour snail LC90 of all the solvent extracts of both the plant parts did not cause any mortality among fish in a mixed population of snail Lymnaea acuminata and fish Labeo rohita. It is proposed that the all the solvent extracts of Euphorbia hirta plant can be used as molluscicides for controlling the vector snails Lymnaea acuminata and Indoplanorbis exustus. Euphorbia hirta is a common medicinal plant of India, which is used in variety of diseases i.e. cough, asthma, colic, dysentery and urinary diseases etc. It is commonly known as Dudhi.

    Keywords: Euphorbia hirta, Lymnaea acuminata, Indoplanorbis exustus, molluscicides, different solvents, Labeo rohita