Soutar et al.
Essential oils as tick repellents on clothing
Exp. Appl. Acarol. 2019, doi.org/10.1007/s10493-019-00422-z
One useful measure to protect against questing ticks is the use of repellents which are applied topically to the skin or to clothing. Most commercially available tick repellents are synthetic molecules like N, N-diethyl-3-methylbezamide (DEET). Alternatively, biologically based repellents, particularly plant-derived essential oils are under investigation. Based on a literature search and various criteria for selection, the following essential oils have been tested: oregano, rosemary, spearmint and thyme. The analyses were carried out in the field by walking in tick-infested habitats by dragging a blanket treated with essential oils or by counting ticks attached to oil-treated trousers. Compared to 20% DEET and ethanol (negative control), spearmint and oregano oil performed comparably. The authors felt that tick counts on trousers may give a better indication of the risk to humans on walking in tick habitats than compared to blanket-dragging alone. A spearmint or oregano oil-based repellent could form an affordable and appealing alternative for people unwilling to use DEET or other synthetic repellents.