Natural Repellents Tell Mosquitoes to Buzz Off

Before applying leaves to skin, "patch test" yourself for allergic reactions by rubbing some repeatedly on your inner forearm for a day or so; if there's no irritating skin reaction, such as redness, itching or swelling, or other adverse response, then, aye, there's the rub for you.

What doesn't work?

Plants that just sit there, no matter what oils they contain, will not repel mosquitoes, including the scented geranium Pelargonium citrosa , sold as "mosquito plant."

Citronella wristbands have proved highly ineffective.

Permethrin is a synthetic poison that mimics a natural one found in chrysanthemums, and is used in pesticides. It is not for use on the skin but is sprayed on clothing, tents, sleeping bags, etc., where tests show it maintains potency for at least two weeks. Several spray products containing 0.5 percent permethrin are on the market, including Repel Permanone. It is also available in lines of outdoor clothing -- one brand is Buzz Off -- though its effectiveness may not last through as many washings as promised.

The attractant level of individuals is based on a complex interaction of many chemical and visual signals. Because something works for one person or against one type of mosquito, doesn't necessarily mean it will for others. A repellent's efficacy depends on which mosquito species is biting and the age, sex, level of activity, humidity levels, and animal magnetism of the human user.

According to preliminary studies, 85 percent of a person's susceptibility to mosquito bites is genetic. Body chemistry plays a role. Female mosquitoes (the bloodsuckers) target those who produce excess amounts of certain acids, such as uric acid, and people with high concentrations of steroids or cholesterol on their skin (byproducts of the body's processing efficiency, unrelated to cholesterol levels). They're lured by a combination of scent, water vapor, and the warm carbon dioxide expelled during breathing and emitted from skin. When a person pants from exertion, the CO2and lactic acid pouring from sweat glands is irresistible to Ms. Quito, who needs blood to develop fertile eggs. Resist going on a swatting rampage when insects hover. Such movements can double the number of mosquitoes you attract. Also, mosquitoes seem drawn to dark rather than light-colored clothing.

Incense has long been used worldwide to foil mosquitoes. Frankincense, myrrh, artemisia, sweet flag and thyme are effective when burned. Citronella candles repel about 40 percent of mosquitoes, according to scientific studies, but only within a range of a few inches.

Dr. T's Mosquito & Gnat Scat ( http://www.yardiac.com/ , or 800-921-3080) is a kitty litter-like substance infused with biodegradable nontoxic oils (lemon grass, mint, and garlic) that, when applied 12 hours before an area will be occupied by guests, vows to ward off mosquitoes and other flying insects for two to three weeks.

Some people swear by a 99.3% liquid garlic concentrate developed as a safe repellent property spray for farmers and sold as Garlic Barrier and Mosquito Barrier ( http://www.garlicbarrier.com/ , http://www.mosquitobarrier.com/ , 800-424-7990.). This should keep everyone away.