Natural Bug Repellents

With summer here and we spend more time outdoors most of us want to protect ourselves with  natural bug repellents instead of using something like DEET.

There are natural insect repellents that are generally considered much safer than synthetic ones. Most of these repellents are derived from oils in plants. Most notable are essential oils—plant oils that are obtained by distillation and have the characteristic fragrance of the plant from which they are extracted.

Some of these oils produce strong odors that are offensive to mosquitoes and other insects and prevent them from landing and biting. Oils reported to possess insect-repellent properties include: clove; citronella; eucalyptus; lemon eucalyptus; cinnamon; castor; rosemary; lemongrass; cedar; peppermint; geranium; thyme; and neem.

Clove Oil: Clove oil has a long history of use in dentistry as a topical anesthetic and antiseptic. The oil is applied directly to the gums to ease toothaches, reduce inflammation, and kill infection. Clove oil has very potent antibacterial, antiviral, and antifungal properties, which makes it useful as a disinfectant and antiseptic, it is also an effective insecticide and repellent.

In an attempt to discover the most potent natural insect repellents, researchers in Thailand tested thirty-eight essential oils with reported repellent properties. The investigators tested the oils at three different concentrations under laboratory conditions using human subjects.

The tested oils were applied at 10 percent, 50 percent, and 100 percent concentrations. Most of the oils could not match the long-term effectiveness of DEET. The most effective oils evaluated in the study were citronella, patchouli, clove, and a Thai herb called makaen (Zanthoxylum limonella). At a concentration of 100 percent, these four oils provided two hours of complete repellency. Clove oil gave the longest complete protection, up to four hours, against the three mosquito species tested.

In a follow-up study, the researchers tested the mosquito-repellent properties of gel products containing either 20 percent clove oil or a mixture of 10 percent clove oil and 10 percent makaen oil. The oil mixture showed complete protection for four hours and an efficacy of 95.7 percent after five hours.

The 20 percent clove oil provided full protection for four hours and 86.8 percent repellency after five hours. In comparison, a DEET-containing product showed similar protection for up to four hours but dropped to 82.7 percent repellency after five hours. Each of these three products gave full protection for the first four hours, with the two essential oil products outperforming the DEET product afterwards.