Every gardener has his or her own way of dealing with the swarms of mosquitoes, gnats, blackflies, and other assorted menaces that get in the way of having a perfect day of gardening. In this special section, we’ve reviewed some of the methods gardeners use to outsmart these pesky creatures. Also, for those readers who live in deer tick country, we’ve included an update on the vaccine that is now available for preventing Lyme disease.

As a full-time gardener growing and selling thousands of heirloom vegetable varieties in Tulsa, Oklahoma, Derrell Merrell spends the majority of each day outdoors. But you won’t find any bug bites on this gardener’s arms or legs, for Merrell just loves garlic. In fact, he loves it so much that he eats three or four raw garlic cloves every day when he sits down to lunch. “The bugs don’t come near me,” he says, adding with a laugh, “but then, nobody else does either.” If you don’t like the taste, Merrell suggests rubbing a garlic clove on the brim of your hat and around your collar and cuffs. “I guess it’s a question of whether the cure is worse than the bite,” he says. “But it does help keep the bugs away.”

Don Barton, of Scurry, Texas, has a slightly sweeter-smelling method of protection against gnats. “Over the last couple of years, our springs have been very hot and wet,” he explains, “so the gnats have been particularly bad.” But you won’t see Barton swatting at those pesky little insects while working the garden he tends with his wife, Judy. His secret? Vanilla extract. Using an old perfume spray bottle, Barton sprays vanilla extract “all over, but especially the tops of my ears where they really like to eat.”

Barton, who works for a local utility company as a purchasing agent, says that his bug repellent has caught on. “A lot of the guys at work borrow it from me,” he says. “It works for us.” Of course, if you spray vanilla extract on yourself, be prepared to have cravings for fresh-baked goods. “My wife says I smell like a big chocolate chip cookie,” he laughs. But no matter what he smells like, Barton is glad to be rid of the gnats. The smell is just the icing on the cake, so to speak.

AHS member Carol Howe, a garden writer living in Rockland, Maine, has discovered an innovative method of protecting herself from the blackflies that call New England home. Howe once worked in a Vermont nursery—“real blackfly country,” she says. “People would come into the nursery in spring asking, ‘Where are the petunias?’ while waving their arms to slap the flies away.” This mad flailing of arms was commonly referred to as “the May salute.” But Howe and her coworkers found that when they wore light-colored clothing, the flies stayed away. “There must be some scientific reason for it,” she says, “but the blackflies just don’t seem to pay attention to you if you’re wearing light clothing.”

So the next time you find yourself in the pharmacy reading the small print on the latest commercial bug repellent, check out your spice rack or even your own closet for an alternative. Who knows? You just may find your idea printed in the pages of The American Gardener.

Christina M. Scott is assistant editor of The American Gardener.

E.B. White probably did not consider a Charlotte the Mosquito character to befriend Wilbur the Famous Pig. Nor has there ever been a mosquito super-hero to save Gotham City or Metropolis. This lack of positive popular culture images of mosquitoes may stem from the fact that, for humans, mosquitoes are annoying, disruptive, and potentially deadly. We have been fighting the plagues of these virus carriers for centuries, and in some areas of the tropics they are still the leading cause of public health problems. Hundreds of years ago Chinese and European peasants burned mugwort (Artemisia vulgaris) to drive away hordes of mosquitoes; this method is still practiced in parts of China today. In many areas of the southern United States, mosquito-control units regularly spray insecticides such as malathion and permethrin throughout neighborhoods during summer to keep these buzzers at bay.

Spraying programs may reduce mosquito populations in areas where the insects are particularly bothersome, but they do not offer complete control and they cause a number of environmental problems of their own. In 1997, for example, thousands of rockfish and other aquatic life were killed on Maryland’s Eastern Shore after permethrin was sprayed near a pond.

Repellents applied to the skin are a more targeted means of protection than resorting to burning herbs or spraying insecticides indiscriminately. However, many repellents have unwanted side effects as well. Problems caused by toxic products can be avoided, or at least minimized, by using natural-based products, instead. But buyer beware: Even natural substances hold potential dangers for users.

Deet

The active ingredient of most popular forms of insect repellent on the market today is diethyl toluamide, commonly known as DEET. Found in such products as Cutter’s and Off!, DEET offers effective, long-lasting protection from mosquitoes and other biting or stinging insects. Aside from fending off a host of pests,“the biggest advantage of DEET is that it keeps working even after it has dried, which is the major drawback to other forms of repellents,” explains Andrew Spielman, professor of tropical public health at Harvard University.

But this popular means of pest control is not without drawbacks. According to a 1986 study published in the Journal of Toxicology and Environmental Health, when DEET products are applied to the skin as much as 56 percent of the dose is absorbed through the skin and up to 17 percent can enter the bloodstream, causing symptoms such as muscle cramping, confusion, and insomnia. Other studies have also indicated that, in severe cases, allergies, dermatitis, and even seizures can result from regular use of products containing high concentrations of DEET.

While it is possible to apply DEET to clothing rather than directly on the skin, be aware that as much as five to 20 times the regular dose needs to be applied to clothes to achieve the same protection as treated bare skin.

Special care must be taken when applying DEET products to young children. Experts point out that children’s lower body weights make them more vulnerable to the potentially dangerous effects of DEET. For this reason, the American Academy of Pediatrics recommends that children should not be exposed to any product with more than a 10 percent concentration.

Citronella

A less-toxic alternative to DEET is citronella oil, a common active ingredient in many natural insect repellents. Distilled from Cymbopogon nardus, a perennial grass native to southern India, Sri Lanka, and widely naturalized throughout Asia, citronella oil is a light yellow, aromatic oil that has been used for centuries to repel insects. Citronella is found in a variety of forms, from creams and sprays to candles and even citronella-treated wristbands. Perhaps the best-known citronella-based products are manufactured by Avon. The company’s Skin-So-Soft line contains insect-repelling products that have consistently stood up to researchers’ efficacy tests. Avon’s product line is generally less potent than DEET-based repellents, but its pleasant odor and safety allows users to reapply it frequently if needed. Furthermore, many of the Skin-So-Soft products are combined with sunscreen.

Just because a product contains citronella, however, does not guarantee that it is an effective mosquito repellent. Some citronella-based sprays and lotions such as Buzz Away and Green Ban have been shown ineffective in a recent study published by the Journal of Medical Entomology. Citronella candles and incense have yielded mixed results: Research indicates that to provide true protection from mosquitoes, you would need to burn so many candles that the smoke and odor would be nearly intolerable.

Finally, many plants that contain citronella oils, such as lemon grass (Cymbopogon citratus) and Pelargonium citrosum ‘Van Leenii’—although advertised as repelling mosquitoes through the constant release of citronella fragrance into the air—have also proved less than effective. This is because citronella’s efficacy as a repellent is dependent on the volatilization of the essential oil into the air. Volatilization requires the heating or crushing and burning of leaves, and its effectiveness varies greatly according to environmental conditions. Unless you want to continuously crush pelargonium leaves in your fingers as you sit on your porch, seek out better repellents.

Neem

Deemed the “Ideal Mosquito Repellent” by the Bio-Integral Resource Center (BIRC)—a non-profit organization that evaluates and publicizes the latest information on less-toxic pest management—one natural repellent that has received high praise is oil from the neem tree (Azadirachta indica), a broad-leafed tree native to India that contains natural pesticides. In India, where at least two million cases of malaria are reported each year, neem oil is rapidly becoming the repellent of choice. There, the oil is mixed with kerosene and burned in lamps; the resulting smoke proves nearly 100 percent effective at keeping the deadly insects at bay.

In the United States and elsewhere, you are most likely to find neem in the form of a mosquito-repellent cream or spray, such as NeemAura Naturals Herbal Outdoor Spray from The Original Neem Company (see source box, above). Researchers concur that just two percent of neem oil in a base of coconut oil is effective for up to 12 hours against many types of mosquitoes. Although reportedly less-than-pleasant-smelling, neem oil is longer lasting and more effective than many popular chemical repellents on several mosquito species.

Other Choices

Another bug repellent and sunscreen combination worth trying is the soybean oil-based product Bite Blocker, although some people find the scent unappealing.

BIRC also recommends using soaps formulated from alkylcylcopentanones or phenylalkanols, or trying the arthritis cream Ben Gay.

If you find applying lotions, oils, and ointments to your skin less than appealing, The Doctor’s Book of Home Remedies, published by Prevention magazine, suggests two dietary supplements that can help repel mosquitoes. Taking the B vitamin thiamine chloride may repel mosquitoes and other insects as it is excreted through the skin. This remedy is not for everyone, however; in some cases hives and rashes result. Another alternative is taking a daily dose of at least 60 milligrams of zinc. Be aware that it takes about a month to build up enough zinc in your system to discourage insects. Take supplements such as these only after consulting your doctor.

Whatever method you choose to repel mosquitoes, it is important to remember that even natural repellents have inherent dangers, notes Don Barnard, research leader of the Mosquito and Fly Research Unit of the USDA’s Agricultural Research Service in Gainesville, Florida. “Many natural repellents need high applications to be effective, and many natural oils in repellent products can cause burning, irritation, and even dermatitis,” he explains. “Because it’s natural does not mean it is completely safe.”

Mosquitoes are not the only insects that trouble gardeners. Biting midges, fleas, and blackflies are just a few of the many pests that can ruin a day outdoors. Here are some less-toxic solutions to these and other nasty nuisances.

Flies

Biting flies can be a menace to anyone who spends time outdoors. And like mosquitoes, they can quickly move from being a simple nuisance to being downright dangerous. Blackflies, for example, will leave a painful welt on their unlucky victims, but their bites can also cause allergic responses that range from more prominent skin irritations to severe systematic illnesses that require hospitalization.

Though nothing has proven 100 percent effective in repelling biting flies—even DEET fails to protect against many species—some of the natural products already mentioned can help. According to The Complete Guide to Pest Control, by George W. Ware, Avon’s Skin-So-Soft products again come to the rescue against blackflies and stable flies. And citronella oil, also a useful stable-fly repeller, may be useful against other kinds of biting flies.

Some varieties of biting flies do not respond to repellents. If avoiding them is not a possibility, put on loose-fitting clothing, followed by small amounts of repellents containing DEET.

Biting Midges

Biting midges (Culicoides spp.) are tiny, blood-sucking insects often referred to as “no-see-ums.” Despite their small size—these insects are a mere 1/25 to 1/8 inch long—they are capable of leaving a painful welt on the skin when they bite. Difficult to actually repel, the best method of avoiding their bite is to apply products such as Skin-So-Soft or Johnson’s Baby Oil to the skin. The mineral oil in these products prevents midges from biting by trapping them like a saber-toothed tiger in a tar pit.

Mosquito Species

With more than 150 different varieties of mosquitoes in the United States alone, humans are lucky not to be the only dish on the mosquito menu; some species prefer birds, frogs, or even plants to humans. The most annoying mosquitoes for gardeners are those in the genus Aedes. These mosquitoes—with a few exceptions—tend to attack during daylight hours, mostly during the peak gardening times of dawn and dusk.

Aedes vexan is prevalent throughout the country during all daytime hours in August, especially after heavy rains. Approaching their unsuspecting prey from below, they attack while gardeners bend over tending to summer plantings. The coastal mosquito (A. solicitans), also known as the New Jersey mosquito, breeds in brackish waters and prefers to wait until nightfall to dive-bomb unsuspecting prey from above. Snow melt mosquitoes, also known as A. excrution—for good reason—are troublesome in spring to gardeners who reside near rivers. Some Aedes species, such as A. coquilettedia, reside in cattail marshes throughout the United States and emerge during midday in midsummer. Other genera, such as Anopheles and Culex, are nocturnal species that prefer to emerge at dusk to search for blood, a time when most gardeners have retired from their chores for the day. Following the old dictum, “Know thy enemy,” find out which species are most prevalent in your area and when they come out to attack, and you will be better prepared to avoid them.

One way to help keep your home and garden mosquito free is to create an environment that discourages mosquitoes from breeding on the premises. Mosquito eggs need still water and high levels of humidity to develop and survive. Common areas around your home that collect water and provide suitable conditions for mosquitoes to breed include rain barrels, buckets, old cans, and drainage lines from rain gutters. The insides of old tires, pet water dishes, the bottoms of planters, and pools that form around water spigots are other favorite breeding grounds. Even water that collects around shrubs, in cavities in tree trunks, under ivy patches, and in mulch provides enough moisture for mosquitoes. Because these insects do not migrate far from where there is available moisture, eliminating moisture build-up in these areas will go a long way toward reducing mosquito visitations to your garden.

For bird baths, collecting pools, ponds, and other small water features around the home, some insecticide companies offer bacteria-releasing repellent rings that kill mosquito larvae without endangering wildlife, pets, or people. Another safe control method for ponds is to stock it with goldfish or mosquito fish (Gambusia affinis). (See box on page 13 for sources.) Be sure your pond is secure during times of high water levels to prevent accidental escape of these fish into local waters; these fierce competitors can threaten the survival of native aquatic species. To protect the fish from neighborhood cats or wandering wildlife, submerge sections of clay pipes in the pond to offer safe shelter. —M.C.M.

Mark C. Mollan is communications assistant at the American Horticultural Society.

AVON, (800) FOR AVON. (Skin-So-Soft products)

Consep, Inc., 213 SW Columbia Street, Bend OR 97702-1013. (800) 367-8727. (Bite Blocker)

Gardener’s Supply Company, 128 Intervale Road, Burlington, VT 05401. (800) 955-3370. www.gardeners.com. (Bug repellent wristband)

The Original Neem Company, 2711 N.W. 6th Street, Suite B, Gainesville, FL 32609. (877) 890-6336. www.neemaura.com (Mosquito-eating Fish)

Natural Pest Controls, 8864 Little Creek Drive, Orangevale, CA 95662. (916) 726-0855.

Richmond Fisheries, 8609 Clark Road, Richmond, IL 60071 (815) 675-6545.

Resources

Bio-Integral Resource Center (birc) publishes Common Sense Pest Control Quarterly, IPM Practioner, and a yearly Directory of Least-Toxic Pest Control Products. For membership informaton, write BIRC, P.O. Box 7414, Berkeley, CA 94707, or call (510) 524-2567.

Common Sense Pest Control by William Olkowski, Sheila Daar, and Helga Olkowski. Taunton Press, Newton, Connecticut, 1991.

Glossary of Plant-Derived Insect Deterrents by Martin Jacobson. CRC Press, Boca Raton, Florida, 1990.

Handbook of Plants with Pest-Control Properties by Michael Grainge and Saleem Ahmed. John Wiley & Sons, New York, 1988.

Herb Research Foundation, 1007 Pearl Street, Suite 200, Boulder, CO 80302. (303) 449-2265. www.herbs.org.

Despite increased public knowledge about Lyme disease, the disease continues to spread (see American Horticulturist, November 1994). Currently, Lyme disease is the most commonly diagnosed vector-borne disease in the United States. Between 1982 and 1996, more than 99,000 cases were reported to the Centers for Disease Control and Prevention (CDC). The number of reported cases is still increasing each year: from 8,257 in 1993 to more than 16,000 in 1996—the last year for which complete statistics are available.

But there’s a new weapon for those in areas where the disease is most prevalent. In December, the Food and Drug Administration (FDA) approved the first vaccine to aid in the prevention of Lyme disease. Developed by Philadelphia-based SmithKline Beecham Pharmaceuticals, the vaccine is being marketed under the name LYMErix. Individuals receive three doses of the vaccine: An initial dose is followed by a second dose one month later, and a third dose 12 months after the initial dose. Studies are underway to determine whether full protection can be achieved with accelerated dosing.

The vaccine works by stimulating specific antibodies directed against Borrelia burgdorferi, the microorganism carried by the black-legged or deer tick (Ixodes scapularis) and the western black-legged tick (I. pacificus) that cause the disease. Researchers hypothesize that when infected ticks feed on humans who have been vaccinated with LYMErix, the vaccine-induced antibodies are taken up by the tick and interact with the B. burgdorferi in the midgut of the tick, thereby preventing transmission of the organism.

A two-year clinical trial involving nearly 11,000 people between 15 and 70 years old, conducted in the Northeast and Wisconsin—areas where Lyme disease is most common—indicate that the vaccine is safe and effective against the transmission of the bacterium. Vaccine efficacy against Lyme disease was 50 percent after two doses, and 78 percent after three doses. The second and third doses—at which point peak immunity is achieved—were administered several weeks prior to the onset of the B. burgdorferi-transmission season in the local geographic area. Researchers note that timing the vaccine injections to be optimally effective during peak tick activity—usually May through June—is critical.

Although LYMErix shows great promise in preventing many cases of Lyme disease, researchers are quick to emphasize that it is not a cure or a treatment for the disease. “It’s important for people to understand that the vaccine is not one hundred percent effective,” says Tom Forschner, executive director of the Lyme Disease Foundation in Hartford, Connecticut. “Nor will it prevent other diseases spread by ticks, such as ehrlichiosis and Rocky Mountain spotted fever.”

As with any new drug, many questions still need to be answered. It is not known how long protection against Lyme disease lasts after vaccination; most likely, boosters will be necessary on an annual basis, much like a yearly flu shot. And the effects on pregnant women, people with autoimmune diseases, and children have not yet been determined. Studies on the vaccine’s efficacy and safety on children under the age of 15 are currently underway.

The decision to use the vaccine should be made after discussing your particular risk factors with your doctor. “I wouldn’t advise everyone to run out and get the vaccine if they don’t need it,” says Forschner. Downsides to the vaccine include cost and possible minor side effects. In addition to doctors’ office visit fees, each of the three shots will cost about $70. Some patients experience minor side effects, including soreness at the injection site, redness and swelling, and flulike symptoms.

The CDC’s Advisory Committee on Immunization Practices recommends that only persons at high risk for B. burgdorferi infection be considered for vaccination: These are people who “reside, work, or recreate in areas of high or moderate risk during Lyme disease transmission season” and who “engage in activities that result in frequent or prolonged exposure to tick infested habitat.”

Whether or not you decide to try the vaccine, it is still important to follow simple precautions to reduce the risk of contracting the tick-borne disease. Forschner notes that for gardeners—especially those in wooded areas—one of the best methods of avoidance is to trim back the vegetation that grows along the border of your lawn or garden and the woods, where ticks are often found. And because deer are the principal maintenance hosts for adult black-legged ticks, keeping those hungry deer at bay is even more important than just for the protection of your favorite plants.

Other tips for protecting yourself include wearing light-colored clothing so you can spot ticks more easily, pulling back long hair and wearing a hat, and tucking pants into socks and shirts into pants so ticks can’t crawl under your clothing. Experts also recommend spraying a product containing DEET on your clothing before going outdoors. Be sure to read product directions carefully before using such repellents, especially on children. After being in a tick habitat, remove your clothes promptly and thoroughly inspect your body for ticks. If you find one, don’t panic; research shows that transmission of B. burgdorferi does not occur until the tick has been attached for 24 to 36 hours. Simply remove the tick carefully with a pair of tweezers, grasping it as close to the mouth parts as possible.

And remember that although most cases have been reported in the Northeast, upper Midwest, and Pacific coast states, Lyme disease can be a problem in nearly every part of the country. According to Forschner, the disease can show up where it’s least expected. “There are pockets of Lyme disease outbreaks in Texas, for example, even though Texas is not known as a high risk area,” he explains. “These pockets may have more cases than New Jersey, which is well known for the disease.” For this reason, it’s important to stay on top of local conditions by consulting your county’s health department.

Christina M. Scott is assistant editor of The American Gardener.

Information about the Lyme disease vaccine can be found on SmithKline Beecham’s LYMErix homepage at www.lymerix.com or by calling (888) LYMERIX.

American Lyme Disease Foundation, inc. 293 Route 100, Somers, NY 10589. (914) 277-6970; www.aldf.com.

Center for Disease Control and Prevention, Division of Vector-Borne Infectious Diseases, 1300 Rampart Road, Colorado State University Foothills Research Campus, P.O. Box 2097, Fort Collins, CO 80522. www.cdc.gov/ncidod/dvbid/dvbid.htm

Lyme Disease Foundation, Inc. One Financial Plaza, 18th Floor, Hartford, CT 06103; (860) 525-2000; 24-hour hotline: (800) 886-LYME. www.lyme.org.

We’d would like to know how you keep bugs at bay in your own garden. Send your stories to Bugs at Bay, The American Gardener, 7931 East Boulevard Drive, Alexandria, VA 22308, or e-mail them to us at editor@ahs.org. We’ll publish the three best anecdotes in a future issue and the writers will receive a gift bag of assorted natural insect repellents.