When it comes to outdoor activities, few pests are as persistently bothersome as the mosquito. Their buzzing can interrupt your enjoyment of nature and their bites will leave you uncomfortable for days to come (to say nothing of the diseases they may carry). For years, the most common solution to an overabundance of mosquitoes was to wear a DEET-based spray. But due to their smell and their tendency to cause dermal irritation, DEET-based bug sprays have begun to fall out of favor.
With DEET out of the equation, some curious outdoor adventurers have begun to experiment with natural methods of mosquito prevention. This includes turning to plant-based and essential oil-based mosquito deterrents described in folk medicine for generations. Some of these natural mosquito prevention solutions hold real promise, while others are simply unable to measure up to DEET’s standard of effectiveness.
Tea tree oil, lemon eucalyptus oil, and cedar oil are three of the tree-based essential oils commonly prescribed for their supposed mosquito blocking capabilities. But do these essential oils really work when it comes to keeping mosquitos at bay? While anecdotal accounts speak positively of all three options, only hard scientific evidence can tell the entire tale of which tree-based essential oil is effective at deterring mosquitoes.
Tea Tree Oil – Does It Work?
Our Conclusion: Maybe
Where It Comes From
Tea tree oil (also known as melaleuca oil) is, as its name suggests, a primary derivative of the tea tree, Melaleuca alternifolia. Known for its pine-like needles and delicate white foliage, the tree can be found natively growing in swampy and stream-adjacent regions of western Australia.
In order to obtain tea tree oil (a categorical essential oil), the tea tree’s leaves are harvested, crushed, and concentrated. The resulting semi-translucent oil is then used for a variety of folk medicinal uses, including providing antimicrobial, antibacterial, and antifungal properties when applied topically. This has led some to assume that tea tree oil can be used to efficiently deter mosquitos from the user’s presence.
A Scientific Primer on Effectiveness
As it stands, research backing up folk medicinal claims of tea tree oil’s antimicrobial, antibacterial, and antifungal properties are yet unproven (in terms of conclusive and replicable evidence). The Mayo Clinic does not currently recommend tea tree oil for these uses, primarily because of lingering questions regarding a safe concentration level for the substance (1).
However, a small body of research has developed around the use of tea tree oil for mosquito prevention purposes. While tea tree oil has not been specifically tested (in the lab or in the field) on mosquitos, preliminary research indicates a worthwhile correlation between the oil’s presence and toxicity to insects.
This can be seen in one key study from 2016 when a team of researchers was able to isolate the active ingredient in tea tree oil that could be credited with its supposed insecticide and repellent qualities. This particular compound was shown to be toxic to some insect species, despite its generally low concentrations in natural tea tree oil samples (2).
Our Thoughts
Based on current research into the topic, tea tree may be effective at deterring mosquitos. However, a full endorsement is not possible due to the lack of evidence supporting this essential oil’s effectiveness in block mosquitos in particular.
This low volume of use-specific evidence relating to tea tree oil has also left the open question of the material’s safety. While tea tree oil has been found to safe for external use (save for occasional skin irritation), it is fully toxic to humans if ingested (1).
To learn more about tea tree oil, its uses, and the research surrounding its effectiveness as a mosquito deterrent, click here.
Lemon Eucalyptus Oil – Does It Work?
Our Conclusion: Yes
Where It Comes From
Lemon eucalyptus oil derives from Corymbia citriodora, commonly known as the lemon-scented gum tree. This smooth, pale white tree is natively found in Australia and can be identified easily due to the strong, citrus-like scent of its leaves. This scent has lead lemon-scented gum tree leaves to be harvested regularly and refined into lemon eucalyptus oil, which itself is used in a variety of perfumery products.
Folk medicine in Australia has long attributed mosquito repellant properties to both the lemon-scented gum tree and its lemon eucalyptus oil derivatives. Even after the introduction of manufactured DEET, Australians have remained firm in their belief that lemon eucalyptus oil is more effective (and far better smelling) than DEET-based bug sprays.
A Scientific Primer on Effectiveness
Out of all tree-based essential mosquito repellants (and indeed, all natural mosquito repellants in general), lemon eucalyptus oil carries the most expansive and conclusive body of evidence in its favor. This volume of evidence has led to the wide adoption of lemon eucalyptus oil for not just homemade solutions, but also commercially-available mosquito repellant products.
A 2011 meta-analytical study’s findings make up the core of modern understandings surrounding lemon eucalyptus’ effectiveness. One field study from Bolivia, for example, found that a 30% PMD topical application of lemon eucalyptus oil was ~97% effective at blocking mosquitos for 4 hours. A similar field study from Tasmania found that a 50% PMD topical application of lemon eucalyptus oil could provide a 100% efficiency rating for up to 7 hours (3).
These results (as well as others in a laboratory setting) have driven follow-up studies in the active ingredients found in lemon eucalyptus oil. Currently, a compound known as PMD (short for para-menthane 3, 8 diol) is believed to provide lemon eucalyptus oil’s chemical composition with its insecticidal properties (3).
Despite this degree of foundational research, commercially-available lemon eucalyptus oil products (such as sprays) are not certified by the US EPA for its ability to deter mosquitos (as compared to DEET). However, independent testing of the products in comparison to one another continues to extoll this essential oil’s capabilities as a natural alternative to DEET-based sprays.
Our Thoughts
There’s no reason to talk around the truth: as it stands, lemon eucalyptus oil is the most effective tree-based essential solution for deterring mosquitos (based upon evidence-based sources). Laboratory and field test have confirmed that this essential oil’s active ingredients are able to engage with and distract the olfactory receptors of many mosquito species, allowing it to provide broad protection over a time period comparable to DEET-based sprays.
Also, compared to many other natural mosquito deterrent methods, lemon eucalyptus oil is easy to obtain and easy to apply without undesirable side effects. Many prominent mosquito spray manufacturers have begun producing lemon eucalyptus oil-based sprays, which are available at most outdoor retailers. These sprays always carry a lemony-fresh scent, making it ideal for use with young family members.
To learn more about lemon eucalyptus oil, its uses, and the research surrounding its effectiveness as a mosquito deterrent, click here.
Cedar Oil – Does It Work?
Our Conclusion: No
Where It Comes From
Unlike most other tree-based essential oils, cedar oil actually derives from a variety of sources. To be specific, cedar oil (also sold as “cedarwood oil”) can be procured through the harvesting and distillation of oils found in the leaves (and occasionally, the bark) of a wide variety of conifer trees (which includes most common pine and cypress trees). This broad base of source foliage has made cedar oil regularly available, with conifer trees found in a variety of geographical climates.
After its creation, cedar oil is used in a variety of industrial and consumer products, including perfumery and food preservation. Cedar oil itself is often a rich gold color due to the large volume of cedrol found in its chemical composition. While it hasn’t been isolated, some believe that this compound is responsible for cedar oil’s supposed insecticidal properties.
A Scientific Primer on Effectiveness
Cedar oil’s insecticidal properties, while anecdotally derived from folk medical sources in India, have not been proven through a conclusive body of research. Even several large-scale meta-analytical reviews of literature relating to natural mosquito deterrent methods are silent when it comes to testing cedar oil, leading to the belief that its value in this domain is negligible at best.
While the current body of research lacks information on the oil’s effectiveness, one peer-edited study was able to conclude that cedar oil could be hazardous when applied in concentrations over 1% (3). As such, cedar oil’s safety (when applied dermally in its undeluded form) is considered inadvisable.
Our Thoughts
Based upon its minimal degree of researched effectiveness and potentially hazardous nature, cedar oil cannot be conclusively dubbed an effective method of naturally deterring mosquitos. Until further testing can be performed to prove that this method is more able to deter mosquitos or is less hazardous to humans at productive concentrations, cedar oil should be avoided for this use.
Instead, those seeking an effective natural mosquito deterrent method should consider another viable option, such as lemon eucalyptus oil (described above, along with evidence backing its effectiveness). To learn more about cedar oil, its uses, and the research surrounding its effectiveness as a mosquito deterrent, click here.
The Best Tree-Based Essential Oil for Mosquito Prevention
Though there are several options in the tree-based essential oil market when it comes to deterring mosquitos, few other options can compare to the proven track record of lemon eucalyptus oil. This essential oil’s unique chemical composition enables it to mask a wearer’s scent from the acute olfactory organs of mosquitos, making them effectively invisible to their blood-sucking proboscises.
At the same time, lemon eucalyptus oil-based mosquito prevention methods don’t suffer from the consistency faults that make DEET-based sprays so bothersome. Commercially-available lemon eucalyptus spray, for example, does not leave behind a sticky or oily residue when applied. It does, however, leave behind a desirable citrusy scent, allowing users to apply this bug deterrent without fear of also deterring their guests and companions.
Also, as noted, lemon eucalyptus oil-based mosquito deterrent mediums are widely available for purchase, both in brick-and-mortar stores and online. This broad availability in a prepared form is ideal for individuals who want to find a viable natural mosquito repellant solution without the need to grow a certain type of plant or refine a certain type of leaf by hand.
Are Essential Oils Worth Trying for Mosquito Control?
At the end of the day, some skeptical observers are quick to question whether or not essential oils are worth using for mosquito control, especially when compared to the proven effects of DEET-based sprays. Simply put, essential oil-based mosquito abatement methods hold a great deal of potential when it comes to protecting those who cannot access or use DEET-based sprays from some of the most debilitating diseases.
In the industrial world, DEET-based mosquito deterrent methods have become widely available, making it cheap and easy for the average citizen to protect themselves from the bothersome bites of mosquitoes. However, in regions where mosquito-borne disease is endemic, DEET-based sprays can be difficult to obtain, making it necessary to turn to geographically-available natural alternatives.
Ongoing research into this domain has been focused on finding viable DEET alternatives that might better serve the needs of these affected populations. Mosquitos in these regions are well-known for carrying debilitating diseases such as malaria, West Nile virus, yellow fever, and dengue fever (among others) (4). As such, it is crucial that more viable mosquito repellant options be developed in order to prevent the continuous propagation of these diseases.
Along the same lines, some individuals either cannot or choose not to wear DEET-based sprays due to an undesirable side effect. For example, builders who work with their hands will often forgo bug sprays (as well as oily sunscreens) in order to retain a full and safe grip on their tools and materials. Along the same lines, a segment of the population may choose to forgo DEET sprays due to a latent allergic reaction triggered by the harsh substance’s presence on their skin.
Regardless of the reason, essential oil-based alternatives to DEET-based mosquito sprays are not only worth researching further, but also worth your consideration next time you select a method of bug abatement for yourself or your family. While there’s no denying that many natural mosquito repellants fall short of expectations or lack research to support their effectiveness, those few viable options – such as lemon eucalyptus oil – may hold the secret to the future of mosquito bite prevention around the world.
Sources
1 – Mayo Clinic Staff. Tea tree oil. Mayo Clinic
2 – Mohamad Adib Bin Edris et al. Insect Repellent Properties of Melaleuca alternifolia. 7 Aug. 2016. DOI: 10.18639/RABM.2016.02.293742
3 – Marta Ferreira Maia and Sarah J Moore. Plant-based insect repellents: a review of their efficacy, development and testing. Published online 2011 Mar 15. doi: 10.1186/1475-2875-10-S1-S11
4 – The United Nations World Health Organization. Mosquito-borne diseases.
Other Forms of Mosquito Repellents
Check out our analyses of the claims behind other forms of mosquito repellents: