Effect of Abiotic Factors on the Molluscicidal Activity of Oleoresin of Zingiber Officinale Against the Snail Lymnaea Acuminata (Report‪)‬

1. INTRODUCTION It has been reported that, oleoresin of Zingiber officinale is a potent molluscicide [1,2]. Fresh water snail Lymnaea acuminata is the intermediate host of liver fluke Fasciola gigantica, causing an endemic fascioliasis in the cattle population of eastern region of the state of Uttar Pradesh in India [3,4]. An effective method to reduce the incidence of fascioliasis is to control the population of vector snails and, thereby, break the life cycle of these flukes [5-8]. Earlier studies have shown that oleoresin of Zingiber officinale has a powerful molluscicidal action on the snail L. acuminate [1,2]. It has also been conclusively shown that acetylcholinesterase (AChE), acid and alkaline phosphatase (ACP and ALP) in the nervous tissue of L. acuminata are very sensitive parameters influenced by molluscicides [7-10]. The aim of the present study was to explore the possibility whether seasonal changes in abiotic factors, viz temperature, pH, dissolved oxygen and carbon dioxide, and conductivity of test water can influence the level of (AChE, ACP and ALP assayed in each month of the year 2006-2007 following exposure to sublethal concentrations (40% and 80%) of 24 h [LC.sub.50] of oleoresin of Z. officinale.