Increasing Efficacy of Eucalyptus Oil as Repellent Against Rattus rattus by Controlled Release Through Encapsulated Wax Blocks

Abstract

Plant based non-lethal repellents are most suitable for rodent control. Present studies were conducted to increase the efficacy of eucalyptus oil as repellent against black rat, Rattus rattus by its controlled release through encapsulated wax blocks. Mature and healthy R. rattus of both sexes were exposed to 5, 10 and 20 % eucalyptus oil encapsulated in wax blocks in laboratory pens in bi-choice tests. Each concentration was applied through three different modes of application i.e. daily, once a week, and every second day per week. Repellent effect of the oil was assessed based on food consumption from treated and untreated sides of a chamber for four days a week. Food consumption was found to be significantly (P ≤ 0.05) low from treatment side as compared to that observed on untreated side at all the three concentrations tested indicating repellent effect of the eucalyptus oil against R. rattus. Percent repellency with eucalyptus oil encapsulated in wax blocks at all the three concentrations was found to be similar. Being the minimum effective concentration, present studies suggest the use of 5 % eucalyptus oil encapsulated in wax blocks as repellent against R. rattus. This method may be used as part of integrated pest management technology for managing rats in enclosed store houses.