Biting bugs can ruin a summer evening in the backyard, but concerns over the long-term use of DEET have left many wary of applying insect repellents that contain this chemical. For those seeking a more natural way to ward off mosquitoes, midges and other pests, several essential oils provide alternatives to DEET-based sprays. These oils are best used where bites are more of a nuisance than a health threat.
In a comparison of 38 essential oils against mosquito bites, clove oil came out on top, providing up to 2 hours of protection against all three mosquito species, as noted in an April 2005 study at Mahidol University in Bangkok, Thailand. Applying undiluted clove oil directly to the skin may cause irritation, but you can find commercial sprays containing concentrations of 10 to 50 percent, or make your own by mixing pure oil into your sunscreen.
Patchouli oil was also among the more effective bug repellents tested in the Mahidol University comparison study. This oil may provide up to 2 hours of complete protection. Although patchouli oil is well tolerated in higher concentrations, the nutty, earthy scent may prove too strong for some. Blending it with sunscreen or a carrier oil such as almond or jojoba oil weakens the scent. Concentrations of 50 (or even 10) percent can still keep the bugs away.
Derived from a plant related to the geranium, this lemon-scented oil has been registered as in insect repellent in the United States since 1948, says the Environmental Protection Agency (EPA). Results with citronella bug sprays vary, however. Insect repellents containing 5 to 10 percent citronella oil may provide anywhere from less than 20 minutes to as much as 5 hours of protection.
This essential oil proved to be one of the top performers in a comparative study of insect repellents published in July 2002 in the New England Journal of Medicine. The two commercial eucalyptus sprays tested kept bugs away from 1 to 3 hours.