“…One such option is biological control (Gormally, 1987(Gormally, , 1988McDonnell & Gormally, 2003). Since then, numerous studies world-wide have investigated their biological control potential of snail hosts of trematode diseases of humans and livestock (Chock et al, 1961;Bhuangprakone & Areekul, 1973;Barraclough, 1983;Beaver, 1989;Maharaj et al, 1992;Appleton et al, 1993;Gbedjissi et al, 2003). Since then, numerous studies world-wide have investigated their biological control potential of snail hosts of trematode diseases of humans and livestock (Chock et al, 1961;Bhuangprakone & Areekul, 1973;Barraclough, 1983;Beaver, 1989;Maharaj et al, 1992;Appleton et al, 1993;Gbedjissi et al, 2003).…”