Study summary
Bioactivity of cedarwood oil and cedrol against arthropod pests
Eller FJ, Vander Meer RK, Behle RW, Flor-Weiler LB, Palmquist DE
Read the original paper- Study type
- Lab
- Year
- 2014
- Species tested
- Fire ants; Ixodes scapularis nymphs
- Published in
- Environmental Entomology 43(3):762-766
- Evidence strength
- Limited evidence
How it was tested
CO2-extracted cedarwood oil was tested for repelling ants in barrier and outdoor bioassays, and cedrol was tested for killing blacklegged-tick nymphs across a dose series.
Summary
A pest-control screen of cedarwood oil (from eastern redcedar) as an ant repellent and its component cedrol as a tick toxicant. It did not test mosquitoes or human skin at all, so its relevance to a skin repellent is indirect.
Key findings
Cedarwood oil significantly repelled ants, including red imported fire ants, keeping them from a food source, and cedrol killed tick nymphs in a dose-dependent way, reaching 100% mortality at the highest dose tested (6.3 mg/ml). No mosquitoes were tested and nothing was applied to skin, so this speaks to cedar's tick-killing chemistry, not to bite protection.
Limitations
No mosquitoes, no human skin, and no protection-time data; the tick result is contact toxicity that kills ticks rather than repelling them off skin.