Citronellol: The Effective Mosquito Repellent Hidden Amongst Citronella Plants
Citronellol, a component of citronella oil, is a potent natural compound with significant mosquito repellent properties. Derived from the leaves and stems of different species of Cymbopogon lemongrass, citronella oil has been used extensively for its perfumery and insect repellent benefits.
Understanding Citronellol
Citronella oil is obtained from the leaves and stems of various Cymbopogon lemongrass species. Commonly used perfumery chemicals like citronellal and geraniol, as well as citronellol, are extracted from this oil. Citronellol, in particular, is one of the key components that contribute to its effectiveness as a natural mosquito repellent.
The Citronella Mosquito Plant Myth
The Citrosa plant, often marketed as a “mosquito plant,” is a species of Pelargonium citrosum that is supposed to repel mosquitoes due to its continuous release of citronella scent. However, research has repeatedly shown that this claim is unsubstantiated. A Journal of the Mosquito Control Association study in 1996 found no significant difference in mosquito landing between citrosa-treated and nontreated subjects.
The Composition of Citronella Oil
The composition of citronella oil is crucial to its effectiveness. While many citronella oil products contain citronellol and geraniol, the Citrosa plant lacks citronellal. This discrepancy explains why the Citrosa plant fails to provide mosquito repellent benefits. Research also indicates that the essential oil components from the Citrosa plant are 95% identical to commercial rose geranium, further debunking its efficacy as a mosquito repellent.
Effective Citronella Grass Species
Fortunately, there are two other species of Cymbopogon that are indeed effective in repelling mosquitoes: Cymbopogon nardus and Cymbopogon winterianus. These grasses are known to contain all three primary components of citronella oil: citronellol, citronellal, and geraniol. When grown in home gardens, these plants can effectively ward off insects such as whiteflies. They also produce commercial citronella oil, which is widely used in candles, soaps, and natural insect repellent sprays.
Citronella Oil as a Mosquito Repellent
Commercial citronella oil, extracted from the aforementioned species, is classified by the Environmental Protection Agency (EPA) as a bio-pesticide, making it a safe and effective repellent. Research has shown that citronella oil, when combined with vanillin, can provide up to three hours of protection against mosquitoes. However, studies have also reported conflicting efficacy, especially when used in consumer products like candles and incense.
Practical Tips for Using Citronella
While citronella oil is a natural and effective mosquito repellent, its effectiveness varies. To maximize its benefits, it is recommended to use it liberally and reapply often, especially in areas with high mosquito activity. Products containing citronella oil should be sprayed on the skin or exposed areas to maintain effective protection.
Conclusion
While the Citrosa plant may be a beautiful ornamental plant, it does not provide mosquito repellent benefits. Effective citronella species and the oil they produce can be effective, but their efficacy can vary based on the specific product. Understanding the composition of citronella oil and the differences between the different species is crucial to making informed choices for natural mosquito repellent solutions.