Insecticidal Activities of Compounds from Sweet Flag (Acorus Calamus) against Red Imported Fire Ants Solenopsis invicta (Hymenoptera: Formicidae)

Abstract

Due to public health and environmental issues, alternatives of synthetic pesticides have been researched for a long time. We also evaluated the toxicity and repellency of the sweet flag (Acorus calamus) powder and two bioactive compounds (α-asarone and β-asarone) against workers of the red imported fire ant (RIFA), Solenopsis invicta under laboratory conditions. Sweet flag powder applied at 1 mg/cm2 or more provided 100% ant mortality within 18 hours, and repelled almost 97% of ants within one hour. Β-asarone was the faster acting compound against RIFA compared to α-asarone and sweet flag powders. The LT50 values inclined exponentially with the increase in the application rate of the test items. On the other hand, repellency did not increase with the increase in the application rate of the test items, but did with the increase in exposure time. Based upon the results of this study, α-asarone and β-asarone, as well as sweet flag powders could be another alternative tool to control the RIFA.

Keywords

• Mortality
• repellency
• α-asarone and β-asarone
• toxicity
• LT50