Insecticidal effect from waste extract of two local spices plant on the rice weevil

Abstract

In an attempt to found natural and cheaper methods for the control of rice weevil, waste extract from two local spices plant were evaluated. Ethanol extracts (mix of leaf and stem parts) of Zingiber zerumbet and Amomum cardamomum were tested on rice weevil for their insecticidal effect. The rice weevil was treated under four different exposure times (0, 1, 2, and 3 hours) and then maintained for 3 weeks in the rice storage. The difference in weight loss of rice (WL) was assumed as feed consumption, and it was an indicator of the insecticidal effect. Percentage of WL were analyzed using ANOVA. The results showed that exposure time was significant to WL on both extracts (LSD test; ? < 0.05). The insecticidal effect with the lowest WL of rice occurred in a 3-hour treatment. The percentage WL in A. cardamomum is lower than those in the Z. Zerumbet. In conclusion, both plants' waste extract decreased the feeding activity on the rice weevil, but the waste extract of A. cardamomum is more effective than Z. zerumbet. This study demonstrates that a waste extract of A. Cardamomum has potency as an insecticide for rice weefil, when appropriate formulation and application methods have been developed.