Introduction:

    Earlier observations indicates that the aqueous extracts of leaf and bark of Euphorbia hirta plant (Family: Euphorbiaceae) have potent molluscicidal activity against freshwater vector snails Lymnaea acuminata and Indoplanorbis exustus (Singh et al., 2003; Singh et al., 2004; Singh et al., 2005 and Singh et al., 2010), but the doses of aqueous extract were so high. So its extraction is necessary for developing new and effective herbal molluscicides. Both the snails are intermediate host of liver-flukes Fasciola hepatica and Fasciola gigantica, which cause endemic fascioliasis in the cattle and livestock of Northern part of India (Hyman, 1970 and Singh and Agarwal, 1981).
    The use of plant products as molluscicide is a simple, easily biodegradable, inexpensive and appropriate technology for focal of snail vector (Kinghorn and Evans, 1975; Kloos and Mccullough, 1987; Marston and Hostettmann, 1985; Singh et al., 1996; Yadav and Singh, 2001; Singh et al., 2004; Singh et al., 2005; Azare et al., 2007; Plan et al., 2008; El-Sherbini et al., 2009 and El-Kamali et al., 2010). Furthermore, investigation of plants used in traditional medicine or recorded in ethno-pharmacological literature provides a ready means of increasing the diversity of available molluscicides and simplifying the choice of selective, ecologically safe snail killing compounds (Fransworth et al., 1987). Euphorbia hirta plant is a common medicinal plant of India, which is used in variety of diseases i.e. cough, asthma, colic, dysentery, genitor urinary diseases (Chopra et al., 1969; Nadkarni, 1976; Kapoor and Mitra, 1979; Jain, 1996; Bhatnagar et al., 2000 and Patel et al., 2009). It is commonly known as Dudhi.
    In the present investigation, molluscicidal activity of different solvent extracts of leaf and bark of Euphorbia hirta plant has been tested against two freshwater vector snails Lymnaea acuminata and Indoplanorbis exustus. Twenty four hour snail LC90 of all the 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.