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Submitted to: Advances in Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 11/9/2015 Publication Date: 1/26/2016 Citation: Chen, J. 2016. Toxicity and efficacy of two emulsifiable concentrates of 2-tridecanone against red imported fire ants. Advances in Entomology. 4(1):37-46. Interpretive Summary: The red imported fire ant is a significant pest affecting humans, wildlife, crops, and livestock. Synthetic insecticides are commonly used in fire ant management. Due to the ever increasing concern to the negative impact of synthetic insecticides on human health and environment, the use of more toxicologically and environmentally benign chemicals is becoming highly desirable. Chemicals from natural products are believed to be more desirable insecticides than conventional synthetic insecticides, due to their rapid environmental biodegradable and low toxicity to non-target organisms. 2-tridecanone is a common constitute of ant defensive secretion. Although 2-tridecanone was proven to be toxic to S. invicta, utilization of this naturally occurring compound in fire ant management has received little attention. In this study, toxicity and efficacy of two 2-tridecanone formulations were assessed. Both showed significant efficacy against fire ants. They may be promising alternatives to current insecticide products for fire ant mound drench. Technical Abstract: BACKGROUND: 2-tridecanone is a major constitute of defensive secretion in tawny crazy ants, Nylanderia fulva that is the only ant species reported to be able to displace red imported fire ants, Solenopsis invicta in the field. 2-tridecanone was proven to be toxic to S. invicta. Although 2-tridecanone is commercially available, utilization of this naturally occurring compound in fire ant management has received little attention. In this study, toxicity and efficacy of two 2-tridecanone formulations were assessed against S. invicta. RESULTS: Two emulsifiable concentrates were prepared using 2-tridecanone as active ingredient, vegetable oil as solvent and polyoxyethylene tridecyl ether as a surfactant. Piperonyl butoxide (PBO) was used as a synergist in one formulation. Both formulations showed significant toxicity in laboratory bioassays. In a field trial, at application rate of 5.28 mL/L and 14 days after mound drench treatment, 100% control was achieved for formulation with PBO and 90% control for the formulation without PBO. CONCLUSION: Both formulations had significant efficacy against S. invicta. Due to the low mammalian toxicity of 2-tridecanone, no involvement of hazardous organic solvents, no phytotoxicity at applied concentrations, and relatively low cost, both formulations are promising alternatives to commercial insecticide products for fire ant mound drench. The outstanding efficacy of both formulations observed in this study warrants further research on their efficacy against other pest insects. |
