THE NATURAL D.I.Y. APPROACH TO REPELLENTS
In addition to eating, or not eating, certain things, using plants around the house, and the tips mentioned in Part 1, you can also make your own topical repellent.
CAUTION: Essential oils should NEVER be put on the skin directly. They are always diluted in a carrier oil such as almond oil. The recipe is usually 3 to 5 drops of essential oil in 1 ounce of carrier oil. Essential oils aren’t regulated by the Food and Drug Administration (FDA) so it’s possible to buy a faulty product! Always buy from a reputable source. If you are going to be traveling in an area where mosquitoes are known to carry diseases such as malaria, yellow fever, or the Zika virus, doctors advise a chemical mosquito repellent to reduce the odds of contracting a dangerous illness. It’s also possible to have an allergic reaction from the active ingredients in essential oils. Before you use any new product, spot-test the product on a small section of your skin and wait an hour or two to make sure that hives or burning sensations do not occur.
1. LEMON EUCALYPTUS OIL: Used since the 1940s, lemon eucalyptus oil is one of the more well-known natural repellents. The Centers for Disease Control and Prevention (CDC) have approved eucalyptus oil as an effective ingredient in mosquito repellent. A recent study showed that a mixture of 32 percent lemon eucalyptus oil provided more than 95 percent protection against mosquitoes for three hours. You can create your own mixture with 1 part lemon eucalyptus oil to 10 parts sunflower oil or witch hazel. Researchers from the University of Florida caution against using the mixture on children under 3 years of age.
2. LAVENDER OIL: Crushed lavender flowers produce a fragrance and oil that can repel mosquitoes. An animal study on hairless mice found lavender oil to be effective at repelling adult mosquitoes. Lavender has analgesic, anti-fungal, and antiseptic qualities. This means that in addition to preventing mosquito bites, it can calm and soothe the skin. You can grow lavender in an outdoor garden or in indoor planters. Crush the flowers and apply the oil to bite-sensitive areas of the body, such as your ankles and arms. Also drop some lavender oil on a clean cloth and rub it onto the skin.
3. CINNAMON OIL: Cinnamon is more than just a great topper to applesauce or oatmeal. According to a study conducted in Taiwan, cinnamon oil can kill off mosquito eggs. It can also act as a repellent against adult mosquitoes, most notably the Asian tiger mosquito. To make a diluted 1 percent solution, mix 1/4 teaspoon (or 24 drops) of oil for every 4 ounces of water. You can spray the fluid onto your skin or clothing, around your home, and onto upholstery or plants. Be careful when applying cinnamon oil, as a concentrated dose can irritate your skin.
4. THYME OIL: When it comes to repelling malarial mosquitoes, thyme oil is one of the best at providing protection. In one animal study, 5 percent thyme oil applied to the skin of hairless mice provided a 91 percent protection rate. You may also want to throw thyme leaves into a campfire. Research shows that burning thyme leaves offers 85 percent protection for 60 to 90 minutes. For a homemade brew, combine 4 drops of thyme oil to every teaspoon of base oil, such as olive or jojoba oil. For a spray, mix 5 drops of thyme oil with 2 ounces of water.
5. GREEK CATNIP OIL: Nepeta parnassica, a member of the mint family related to catnip, can ward off mosquitoes. The white and pink flowers grow up to 18 inches, but it’s the extract and oil from the bruised leaves that’s the most valuable. One study found that oil from the plant could repel mosquitoes effectively for two to three hours. Researchers at Iowa State University also found catnip to be 10 times more effective than DEET at repelling mosquitoes.
6. SOYBEAN OIL: According to the University of Florida Medical Entomology Laboratory, soybean-based products like Bite Blocker for Kids (2 percent soybean oil) could provide long-lasting protection from mosquitoes. In addition to soybean oil, you can also add a little lemongrass oil to your home mixture. The combination has been tested to guard against different species of mosquitoes.
7. CITRONELLA OIL: Citronella is a common natural and effective essential oil that works against mosquitoes. Made from a mix of herbs, it’s an ingredient in many mosquito repellents. When outdoors, citronella candles can provide up to 50 percent extra protection. Research says that the formulation of citronella is important to how effective it is. When the product is formulated correctly it’s as effective as DEET, and can protect you for up to about two hours. If the formula isn’t right, citronella can evaporate in about 30-60 minutes and leave you unprotected (the Java type of citronella is about twice as good as the Ceylon type).
8. TEA TREE OIL: Tea tree oil, or melaleuca oil, is a popular essential oil from Australia. This oil is known for its antiseptic, antimicrobial, and anti-inflammatory properties. But recent studies also suggest that tea tree oil may be an effective insect repellent. Field testing shows that repellents containing tea tree oil are effective against mosquitoes, bush flies, and biting midges.
9. GERANIOL: Geraniol is a type of alcohol used as a fragrance or flavor. It’s from plant oils like citronella, lemongrass, and rose. As an ingredient in mosquito repellent, it’s known to be effective for two to four hours, depending on the species. Keep away from your eyes and try to avoid use if you have sensitive skin. Geraniol may cause eye and skin irritation.
10. NEEM OIL: CAUTION; Although neem oil is advertised as a natural alternative, there are mixed results about its effectiveness. A recent study about the effectiveness of neem oil in Ethiopia found that it offered more than 70 percent protection for three hours. Neem oil is not approved as a topical repellent because it can cause skin irritation. It’s still best to use DEET when traveling to a country that’s high-risk for mosquito-borne diseases. To repel mosquitoes with neem oil, dilute 50 to 100 milliliters of neem oil in water, oil, or lotion. It’s also important to choose extra virgin, cold-pressed neem oil.
CITRONELLA vs LEMMONGRASS [Pictured: Left Lemongrass. Right, citronella grass] (This is what happens when you have too much time on your hands!)
A loyal reader of mine (different forum) asked what the difference is between citronella and lemon grass, here's the answer:
Ever since Don Sterling asked if I could give a list of wild plants used to repel mosquitoes, it not only sparked a small series of informative posts (Thanks, Don, I think), it also sparked a number of ADDITIONAL questions on the subject (again, thanks a LOT!… DON!!). 😉 The two top questions were; What’s the difference between lemongrass and citronella? And, how do you make your own repellent?
LEMONGRASS AND CITRONELLA COMPARED
Lemongrass and citronella are cousins. They are both dark green, grow in “clumps”, are used for teas and various culinary purposes, and as essential oils, they are both processed in the same manner and may be used as a type of pesticide/repellent. This is where they start to differ…
Lemongrass is a tropical herb plant that grows to between 3 to 6 feet tall, has a strong lemony scent and beige base stems. It is used in helping with some digestive problems and is often used in the cosmetic industry for the manufacture of perfumes, soaps and deodorants. Citronella grasses are a pelargonium species (in the geranium family) that grow to about 6.5 to 8 feet tall, have a citrusy-citronella scent and have reddish base stems. It is used as an antiseptic/antifungal and is often used in candles, potpourri, lotions and other products to help ward off insects. But between the two, citronella grasses are superior as a mosquito repellent.
Citronella species look like a geranium, but do not have the pretty flowers geraniums are known for. The leaves are slightly rougher than regular geraniums and when you rub the leaf it smells like citronella, otherwise it looks like a geranium. There are four types of citronella grass (that I know of) but the two main types used for the production of citronella oil are Ceylon (Cymbopogon nardus) and Java (Cymbopogon winterianus). Citronella oil is considered a biopesticide (biochemical), is EPA registered as an insect repellent/feeding depressant and as an animal repellent with a non-toxic mode of action. The principal chemical constituents of citronella oil are citronellol and geraniol, and are antiseptics (hence their use in household disinfectants and soaps). Citronellol is what makes it effective as a mosquito repellent. There is about TWICE as much citronellol in the Java type as the Ceylon type making it preferred, however, that also makes the Java type more toxic (category III = slightly toxic) compared to the Ceylon type (category IV = practically non-toxic).
CAUTION: For external use ONLY! Avoid contact with eyes. Discontinue if irritation or rash appears. Use on children under 6 months of age ONLY with the advice of a physician, here are reports of poisoning in children, one toddler died after swallowing insect repellent that contained citronella oil. Do NOT use essential oils by themselves!! Citronella oil seems safe for most people in the small amounts normally found in foods however, it might cause skin allergies in some people. It’s UNSAFE to inhale citronella oil, lung damage has been reported. Not enough is known about the use of citronella oil during pregnancy and breast-feeding. Stay on the safe side and avoid use.
There is INSUFFICIENT scientific data in use for worm infestations, fluid retention, spasms, etc. Citronella oil is volatile/unstable, meaning it will evaporate readily, which is why you need a stabilizing, carrier oil/mix, so in mosquito-infested areas, you WILL need to reapply! (you may want to use a citronella candle or two and/or a smoky fire on the trail). How often you need to reapply depends mostly on the mix used in making the application and the application type. Lotions are longer lasting than sprays, but generally, protection will last anywhere from about 30 minutes for soaps to about 3 hours for lotions. As to “recipes”, it can be as simple as 15 drops lavender oil, 10 drops citronella oil, 5 drops lemon oil (mix, put in a spray bottle, fill the rest with water. Shake and spray away from eyes) or something more complicated like the following:
HOMEMADE CITRONELLA SPRAY
1/2 cup distilled water, warmed up a bit
1/8 teaspoon Epsom salt
1/2 cup witch hazel 10 drops citronella essential oil
10 drops lemon eucalyptus essential oil
10 drops lemongrass essential oil
5 drops tea tree essential oil
5 drops cedar wood essential oil
DIRECTIONS: Pour the water into an 8oz (250ml) dark glass or P.E.T. plastic spray bottle. Add the Epsom salt and shake until the salt is dissolved. (The salt emulsifies the essential oils and the water so it's not as big a deal if you forget to shake the bottle before using your bug repellent.) Pour in the witch hazel. Add the essential oils. That's it! Simple! To use, just spritz onto the bits you want the bugs to avoid. Don't spray it into your eyes or mouth because it will sting and also taste bad.
HOMEMADE CITRONELLA LOTION
2 to 2 1/2 tblsp.(8-10g) emulsifying wax (depending on how thick you want it)
1/2 teaspoon (2g) stearic acid (a plant-based stabilizer)
1/3 cup (75ml) grapeseed oil
1/2 cup (125ml) distilled water or lavender floral water 1 teaspoon (5ml) vitamin E
10 drops grapefruit seed extract (natural preservative)
10 drops citronella essential oil
10 drops lemon eucalyptus essential oil
10 drops lemongrass essential oil
DIRECTIONS: Stir together the oil, emulsifying wax and stearic acid in the top part of a double boiler, warming slowly over a low heat until the wax is completely melted. Remove from heat and pour in the Vitamin E. In a separate pot on the stove, gently warm the water/hydrosol just until lukewarm. Slowly pour the water/hydrosol into the oil, stirring constantly with a wire whisk until the mixture is thick, cream-colored and smooth. Let cool slightly. Stir in the essential oils and the grapefruit seed extract. Pour the homemade bug repellent lotion into a clean, sterilized 8oz (250ml) dark glass or P.E.T. plastic bottle and allow it to cool before putting the lid on. Shake the bottle occasionally as the lotion cools to prevent the ingredients from separating. Store in a cool, dark place.