Evaluation of four commercial natural products for repellency and toxicity against the lone star tick, Amblyomma americanum (Acari: Ixodidae)

Authors: Machtinger, Erika; Li, Andrew

Submitted to: Experimental and Applied Acarology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/1/2017
Publication Date: 11/22/2017
Citation: Machtinger, E.T., Li, A.Y. 2017. Evaluation of four commercial natural products for repellency and toxicity against the lone star tick, Amblyomma americanum (Acari: Ixodidae). Experimental and Applied Acarology. 73:451-460.

Interpretive Summary: Lone star ticks are important pests that can transfer pathogens that can cause disease in humans and animals. These ticks are common, aggressive, and expanding in distribution over the United States. There are public concerns over the safety of common repellents like DEET, so it is necessary to investigate more naturally derived compounds as potential repellents against lone star ticks. In this study, several commercially available formulas of essentials oils and other botanical extracts were tested for their ability to repel and kill nymphs and adult lone star ticks. These results were compared to DEET and permethrin. Two of the products, Wondercide and Essentria IC3 were as effective as DEET at all concentrations. These four products may offer a natural way to repel lone star ticks, but more testing is needed to evaluate application rates and need for reapplication of products to maintain effectiveness.

Technical Abstract: Lone star ticks are aggressive ectoparasites of domestic and wild animals, as well as humans. These ticks can transmit many pathogens that cause disease including Erhlichia and tularemia. Common compounds used for personal protection and area sprays are N-diethyl-3-methyl benzamide (DEET) and permethrin, but public concern over personal and environmental safety require the development of new, safer products. In the current study, four commercially available products (Wondercide, Essentria IC3, Vet’s Best, and Mosquito Barrier) were tested for both repellent and toxic effects against lone star tick nymphs and adults. Overall, all four products were more effective against nymphs than adults. Wondercide and Essentria IC3 were as toxic to nymphs as permethrin at concentrations of 3.13% and higher and as repellent as DEET at all concentrations. Nymphs were also repelled by Mosquito Barrier and Vet’s Best, but these products had about half or less of the repellent effects of Wondercide and Essentria IC3 at most of the concentrations. Adult ticks were repelled similarly by all products at all tested concentrations, but at lower levels than nymphs. Toxicity of the four tested products on adults was similar at concentrations of 12.5% and below, less than half of what was observed with permethrin with declining effectiveness as concentrations decreased. Overall, these four products may offer a natural way to repel lone star ticks, but further field testing is needed to determine rates of application and residual activity.