Bioactivity of two extracts from <i>Alpinia officinarum</i> rhizome against <i>Tribolium castaneum</i> (Herbst) adults

Abstract

The bioactivities of two solvent plant extracts prepared from Alpinia officinarum Hance rhizome, a traditional Chinese herbal plant were investigated against Tribolium castaneum (Herbst) adults in the laboratory. The rhizome extracts were prepared by n-hexane and methylene chloride extraction. Both extracts had significant repellent activity against T. castaneum adults with over 89% at class V at the dosage of 0.10 μl/cm,sup>2 and above after 24 h exposure. The repellent activity significantly increased with increased exposure dosage. Both extracts also had strong fumigant activity against T. castaneum adults with over 80.0% mortality at the highest dosage tested of 80 μl/l air after 48 h of exposure. Mortality was dose dependent for both extracts. Regardless of extraction method A. officinarum rhizome extracts were demonstrated to have bioactivity against T. castaneum adults. These results suggest that the A. officinarum rhizome extracts have potential for integrated pest management programs of T. castaneum population.

Key words: Alpinia officinarum rhizome extract, Tribolium castaneum (Herbst), fumigant activity, repellent activity, plant extract.