Mosquitoes are common outdoor nuisances, and many seek natural ways to deter them. Lavender, with its pleasant fragrance, is often considered a potential solution. Understanding the science behind lavender’s interaction with mosquitoes provides clarity on its effectiveness.
Lavender’s Scent Compounds
Lavender’s distinct aroma comes from a complex mixture of volatile organic compounds (VOCs) produced by the plant. The primary components responsible for its scent are linalool and linalyl acetate. Linalool is a terpene alcohol, contributing floral and sweet notes. Linalyl acetate, an ester formed from linalool, also contributes a sweet, floral, and fruity aroma, enhancing its characteristic pleasant scent. These compounds, along with others like (E)-beta-Ocimene, terpinen-4-ol, and camphor (in smaller quantities for Lavandula angustifolia), are key to its aromatic profile.
How Mosquitoes Find Us
Mosquitoes possess a sophisticated sensory system that enables them to locate hosts. Their host-seeking behavior is a multi-step process involving different cues. Mosquitoes initially detect carbon dioxide (CO2) from exhaled breath, which acts as a long-range attractant from 10 meters or more away.
As they approach, other cues become important. They are drawn to chemicals emitted from human skin, such as lactic acid, uric acid, and ammonia, which are produced by skin bacteria interacting with sweat. Body heat and humidity also serve as close-range attractants. Visual information aids their landing behavior.
Lavender’s Effect on Mosquitoes
Scientific studies on lavender’s effectiveness as a mosquito repellent show mixed results, with its potency varying from mild to moderate. Research suggests that lavender’s repellent properties are primarily due to compounds like linalool, which can disrupt a mosquito’s sensitive olfactory organs, making it harder for them to locate a host. A 2009 study found lavender oil had a 93% repellent rate against mosquitoes indoors, but a lower rate of around 53% outdoors, suggesting environmental factors influence its efficacy.
Another study in 2019 noted an 80% repellent rate for lavender essential oil for up to eight hours. However, some research indicates that while lavender provides initial repellency, its effect can decrease over time, especially when compared to synthetic repellents like DEET. The concentration of the essential oil and the specific species of lavender, such as Lavandula angustifolia, can also influence the results. Its repellent effect is often considered mild and short-lived.
Using Lavender Around Mosquitoes
For those using lavender as a mosquito deterrent, it should not be relied upon as a primary control method. Planting lavender in gardens, particularly near seating areas or entryways, can provide a localized deterrent effect due to the scent released from the plants. Varieties known for strong fragrance, such as English lavender (Lavandula angustifolia), may be more effective. Brushing against the plants can release more of their fragrant oils.
Lavender essential oil can be applied topically to the skin, but it must be diluted with a carrier oil, such as coconut or jojoba oil, to avoid skin irritation. A common recommendation is 1-2 drops of lavender oil per ounce of carrier oil, or a 5-10% dilution for a stronger repellent. Homemade sprays can also be made by mixing lavender essential oil with water or witch hazel, and can be applied to clothing or outdoor areas. Always perform a patch test before widespread application, and avoid sensitive areas like eyes and mucous membranes.