Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/29/2007
Publication Date: 4/1/2008
Citation: Chen, J., Cantrell, C.L., Duke, S.O., Allen, M.L. 2008. Repellency of Callicarpenal and Intermedeol Against Workers of Imported Fire Ants. Journal of Economic Entomology.101(2):265-271 (2008). Interpretive Summary: The federal government has established restrictions on the interstate movement of plants with soil that may be infested with fire ants. Ball and burlap nurseries are affected by these fire ant quarantine regulations which reduce the spread of imported fire ants into non-infected areas of the country. Fire ant repellent compounds were found in American beautyberry which effectively repelled red imported fire ants, black imported fire ants, and their hybrid. These compounds may prove to be useful in various fire ant repellent formulations.
Technical Abstract: Callicarpenal and intermedeol are two terpenoids isolated from American beautyberry (Callicarpa americana L., Verbenaceae) leaves. The repellency of these two terpenoids against workers of red imported fire ants, Solenopsis invicta Buren, black imported fire ants, Solenopsis richteri Forel, and a hybrid of these two species was evaluated using multiple-choice digging bioassays. A total of six colonies, two colonies from each species and hybrid, were tested. Callicarpenal showed significant repellency at concentration as low as 50.00 ppm against S. invicta and 6.25 ppm against S. richteri and the hybrid. Intermedeol showed significant repellency at 0.75 to1.50 ppm against S. invicta, 6.25 ppm against S. richteri, and 1.50 to 6.25 ppm against the hybrid. Callicarpenal and intermedeol were compared with octanoic acid, a known fire ant repellent, at the 25.00 ppm level using two-choice digging bioassays. Callicarpenal showed significantly greater repellency than octanoic acid against both S. richteri colonies and one hybrid colony; however, there was no significant difference between callicarpenal and octanoic acid for both S. invicta colonies and the other hybrid colony. Intermedeol showed significantly greater repellency than octanoic acid against all colonies of S. invicta, S. richteri and the hybrid colonies.