Flies can be a nuisance, especially during the warmer months. Their persistence and ability to spread germs makes finding ways to repel them a priority. Research has shown that certain essential oils are effective at deterring flies. Using these natural repellents can provide a safe and environmentally friendly alternative to harsh chemical pesticides.
Essential Oils That Repel Flies
Several studies have identified essential oils that exhibit fly repellent properties:
Catnip Oil
Catnip oil, derived from the Nepeta cataria plant, contains the active compound nepetalactone which has been found to repel houseflies effectively. One study showed that catnip oil repelled flies for up to 6 hours (1). The repellent effect is likely due to nepetalactone acting as an irritant that flies avoid.
Citronella Oil
Citronella oil is commonly used in commercial insect repellents. The geraniol and citronellol compounds found in citronella oil have demonstrated fly repellency. In one study, microencapsulated citronella oil led to an 80% reduction in stable fly feeding (2). The aroma appears to deter flies from landing and biting.
Geranium Oil
Like citronella oil, geranium oil contains citronellol which gives it fly repellent capabilities. In a comparative study, geranium oil was moderately effective at repelling biting flies (3). The exact repellent mechanism is unclear but may be attributed to irritation or masking of attractants.
Lavender Oil
Lavender oil has been shown to repel Drosophila flies in lab studies. The active ingredients linalool and linalyl acetate likely affect fly nervous system function to cause an avoidance response (4). Lavender oil displayed a similar level of repellency as commercial DEET repellents.
Peppermint Oil
Peppermint oil contains menthol which research indicates has an insect repellent effect. In one study, the topical application of peppermint oil provided complete protection against Drosophila flies for up to 3 hours (4). Peppermint oil seems to act as a neurotoxicant to repel flies.
Thyme Oil
Thyme oil strongly repelled Drosophila suzukii flies in a choice test, with its thymol and carvacrol compounds playing a key role (5). At higher concentrations, thyme oil led to fly mortality, suggesting it has toxic and repellent effects.
Rosemary Oil
Similar to thyme oil, rosemary oil and its active ingredient 1,8-cineole demonstrated repellency against Drosophila flies (4). After 3 hours, rosemary oil provided approximately 90% protection against fly bites.
Lemongrass Oil
Lemongrass oil contains citronellal that gives it insect repellent capabilities. In one study, lemongrass oil decreased stable fly feeding by 17-57%, depending on the oil concentration (2). The antifeedant properties prevent flies from biting treated surfaces.
Using Essential Oils as Fly Repellents
There are a few recommended ways to harness the fly repelling power of these essential oils:
- Apply diluted oils directly to the skin for protection. Use a carrier oil like coconut or jojoba oil to dilute.
- Use oils in homemade sprays and apply to surfaces where flies are problematic.
- Place drops of oil on cotton balls and leave in areas flies frequent like patios and window sills.
- Burn oils in candles or oil diffusers to repel flies from outdoor living spaces.
- Mix oils into pet shampoos or sprays to repel flies from pets. Use caution and properly dilute oils before applying topically to animals.
- Incorporate repellent plants like lavender, mint, lemongrass and catnip into landscaping and gardens.
Essential oil fly repellents provide a safer alternative to harsh pesticides. Through their aroma and toxicity, they effectively ward off fly activity. Some essential oils like catnip, citronella, lavender, peppermint, and lemongrass can be used to make sprays, repellents, and diffusers that help reduce fly infestations.
References
- Kumar, P., Mishra, S., Malik, A., & Satya, S. (2011). Repellent, larvicidal, and pupicidal properties of essential oils and their formulations against the housefly, Musca domestica. Medical and Veterinary Entomology, 25(3), 302-310. https://doi.org/10.1111/j.1365-2915.2011.00945.x
- Baldacchino, F., Tramut, C., Salem, A., Liénard, E., Delétré, E., Franc, M., … & Jay-Robert, P. (2013). The repellency of lemongrass oil against stable flies, tested using video tracking. Parasite, 20, 21. https://doi.org/10.1051/parasite/2013021
- Zhu, J., Zeng, X., Berkebile, D., Du, H., Tong, Y., & Qian, K. (2009). Efficacy and safety of catnip (Nepeta cataria) as a novel filth fly repellent. Medical and veterinary entomology, 23(3), 209-216. https://doi.org/10.1111/j.1365-2915.2009.00826.x
- Renkema, J. M., Wright, D., Buitenhuis, R., & Hallett, R. H. (2016). Plant essential oils and potassium metabisulfite as repellents for Drosophila suzukii (Diptera: Drosophilidae). Scientific reports, 6(1), 1-10. https://doi.org/10.1038/srep21432
- Renkema, J. M., Buitenhuis, R., & Hallett, R. H. (2017). Reduced Drosophila suzukii infestation in berries using deterrent compounds and laminate polymer flakes. Insects, 8(4), 117. https://doi.org/10.3390/insects8040117
