Natural Mosquito Repellent

Organic Mosquito Repellents

Javedan Siddiqui

The most common mosquito and bug repellant is DEET, found in products like OFF, Cutter, and 3M. As effective as DEET may be, it is also a dangerous chemical for humans, especially children. DEET has been shown to cause brain-cell death and trigger behavioral changes indicative of neurological damage in rats after frequent or prolonged use.

Fortunately, there are several safe, natural alternatives to DEET repellants. A few years ago, Avon’s Skin-So-Soft bath oil received media attention when consumers reported its mosquito repellent effect. Following consumer reports, studies were done to determine why the bath oil was warding off these pests. They found that Skin-So-Soft bath oil has a minimal repellent effect, 10 times less effective than 12.5% DEET. These studies concluded that the repellent effect may be due to the bath oil’s fragrance or other components of its formulation. Avon never marketed the bath oil as an insect repellent, but instead came out with Avon Skin-So-Soft Bug Guard with insect repellent IR3535 (3-[N-butyl-N-acetyl]-aminopropionic acid). A synthetic available exclusively through the Avon Corporation, IR3535 is labeled for use against mosquitoes, ticks, body lice, and biting flies. This synthetic was used in Europe for 20 years before it was registered by the EPA in 1999. Studies have shown this repellent to be effective for 4-6 hours, but 10-100 times less effective than DEET.

Another natural alternative to DEET is lemon eucalyptus. Registered with the EPA, and recommended by the CDC, lemon eucalyptus was shown in studies to be one of the most effective natural mosquito repellents. In a 2002 study in the New England Journal of Medicine, lemon eucalyptus found in Repel Lemon Eucalyptus Repellent provided 120.1 minutes of mosquito protection, more than a repellent with a low concentration of DEET. Another study by the US Department of Agriculture compared four synthetic mosquito repellents and eight natural mosquito repellents and found that Repel Lemon Eucalyptus was the most effective repellent. Consumer Reports has also found lemon eucalyptus to be the best non-DEET repellent, with the only criticism from some consumers being the odor.

The same NEJM study and USDA study that looked at lemon eucalyptus also studied the efficacy of geranium oil and soybean oil, both found in the product Bite Blocker. The NEJM study found that soybean oil-based repellents were effective at protecting from mosquito bites for about 1.5 hours; and the geranium oil alone gave very short-term protection, with a maximum of 20 minutes. So the soybean oil in Bite Blocker is the most active ingredient, providing the most protection. The USDA study ranked Bite Blocker number two, after Repel, but more effective than low concentrations of DEET.

An interesting repellent that is not available on the market, but that you can actually grow in your yard, is catnip. In a study done by the Iowa State University Department of Entomology, researchers found that small doses of catnip essential oil is 10 times more effective at repelling mosquitoes than larger doses of DEET. There is no patent on catnip as a mosquito repellent, so you will not find any commercial products with catnip as the active ingredient, but you can make your own repellent at home! The species of catnip that contains the mosquito repellent compounds is the perennial herb Nepata cataria. Below are two recipes from Ann Lovejoy of the Seattle PI newspaper:

CATNIP MOSQUITO SPRITZ

· 2 cups catnip, stemmed

· 3-4 cups mild rice vinegar

· Rinse herbs, roll lightly with a rolling pin, then place them in a clean quart jar and cover with vinegar. Seal jar and store in a dark cupboard for two weeks.

· Shake jar lightly every day or so for two weeks. Strain into a clean jar, seal and refrigerate for up to 6 months unused.

· To use, spritz on exposed skin and around outdoor dining area.

CATNIP AND ROSEMARY MOSQUITO CHASING OIL

· 2 cups catnip, stemmed

· 1 cup rosemary, cut in 6-inch sprigs

· 2 cups grapeseed oil or any light body-care oil

· Roll herbs lightly with a rolling pin and pack into a clean jar. Cover with oil, seal jar and place in a cool, dark cupboard for two weeks.

· Shake jar lightly every day or so for two weeks. Strain into a clean jar, seal and refrigerate for up to 8 months unused.

· To use, rub on exposed skin.

Another popular mosquito repellent for outdoor seating areas is citronella candles. Citronella oil is derived from dried cultivated grasses. At the University of Guelph, they assessed the effectiveness of 3% citronella candles and 5% citronella incense in protecting against mosquito bites. The study found that subjects who were positioned near the candles had 42.3% less bites, and those near the citronella incense had 24.2% fewer bites, than those who were near neither. Since the citronella candles have limited effectiveness, they are used best in conjunction with other repellents. Citronella oil is also available in sprays and lotions, but some people may have skin sensitivities to the oil.

There are several other natural and botanical compounds that are being studied for their repellent effects – fennel oil, thyme oil, clove oil, celery extract, neem oil, vitamin B1, and garlic. The effectiveness of these substances is still unknown. However, if you are looking for a natural alternative to DEET, products like Avon Skin-So-Soft Bug Guard, Repel, and Bite Blocker will provide the best protection without risk of detrimental side effects and bodily damage.

Other tips to avoid insect bites:

· Wear light-colored, loose clothes and avoid scented products when outdoors, especially from dusk to dawn, which is the peak feeding time for mosquitoes.

· Remove areas of standing water near your house as they can be breeding areas for mosquitoes.

· Wear closed shoes and a hat to avoid ticks. Tuck pants into socks, and wear long sleeves.

· Inspect your body after exploring wooded or grassy areas.

Sources:

Adler, Tina. “Mauling Mosquitoes Naturally.” Science News. 27 April 1996. 148 (17): 270-274. Accessed 26 June 2011 at http://sciencenews.org/pages/pdfs/data/1996/149-17/14917-12.pdf

Barnard Donald R et al. "Laboratory evaluation of mosquito repellents against Aedes albopictus, Culex nigripalpus, and Ochierotatus triseriatus (Diptera: Culicidae)." Journal of Medical Entomology. 41.4 (2004): 749-57.

Consumer Reports. "Insect repellents: Which keep bugs at bay?" Consumer Reports. June 2006. 19 June 2006 <http://www.consumerreports.org/cro/health-fitness/beauty-personal-care/insect-repellents-606/overview/index.htm>

Fradin Mark S et al. "Comparative efficacy of insect repellents against mosquito bites." New England Journal of Medicine. 347.1 (2002)13-8.

Hendrick, Bill. “6 Insect Repellents Get High Marks.” WebMD Health News. 25 May 2010. Accessed 26 June 2011 at http://www.webmd.com/skin-problems-and-treatments/news/20100525/6-insect-repellents-get-high-marks

Lindsay L. Robbin et al. "Evaluation of the efficacy of 3% citronella candles and 5% citronella incense for protection against field populations of Aedes mosquitoes." Journal of the American Mosquito Control Association. 12.2 (1996):293-4.

Lovejoy, Ann. “Grow your own mosquito repellent.” Seattle PI. 9 October 2002. Accessed 26 June 2011 at http://www.seattlepi.com/default/article/Grow-your-own-mosquito-repellent-1097992.php#ixzz1MjHn3N1q

Ogg, Barb Ph.D. “What’s the Scoop on Insect Repellents?” University of Nebraska-Lincoln Extension. August 2008. Accessed 26 June 2011 at http://lancaster.unl.edu/pest/resources/InsectRepel.shtml

Trongtokit Y et al. "Comparative repellency of 38 essential oils against mosquito bites." Phytotherapy Research. 19.4 (2005):303-9.

Wong, Cathy. “Natural Mosquito Repellents.” About.com Alternative Medicine. 23 June 2006. Accessed 26 June 2011 at http://altmedicine.about.com/od/aznaturalremedyindex/a/mosquito.htm