Effects of Oleander Leaves (Nerium oleander) against Metabolism, Activity Pattern, and the Leaves Potency as Rice-Field Rat Repellent (Rattus argentiventer)

Nerium oleander is a plant that has historically been known as a poisonous plant in the world. In several studies, all parts of the oleander are toxic and used to control pests. However, studies on the effects of oleander leave against Rattus argentiventer as a major agricultural rodent pest are limited. This research aimed to probe the potency of oleander leaves that extracted in methanol as rice-field rat repellent by T-test analysis using three replications on mature female and male rice-field rats. The experiments involve a choice test (T-maze arena) and no-choice test (metabolic cage) from February until May 2019. The result of the experiment showed that rice-field rats on the T-Maze avoided consuming food and beverage that close to the methanol extract of oleander leaves treatment. Therefore, the treatment in metabolic cage caused metabolic disorder of rice-field rats, which was indicated by the decrease of the average consumption of food by 2.27 g and excretion of feces by 0.67 g, and also the increase of average consumption of beverage by 4.53 ml, excretion of urine by 1.25 ml. Besides, the treatment also caused daily activity patterns disorder of rice-field rats, which was significantly indicated by the increase of the average percentage of time for resting activities by 2.16 % and the decrease of time for locomotion and nesting activities (by 0.92 % and 1.25 % respectively). In conclusion, oleander leaves have the potential to provide a repellent effect on rice-field rats.