The Lowdown on Lyme Disease

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Yet Lane cautions against feeling too secure, especially if you find yourself in a hardwood forest in northwest California, where Lyme disease is a serious threat. In those forests, as in the Northeast and along damp river corridors across the Midwest, ecological factors appear to favor the prevalence of Lyme disease and the ticks that carry it.

TAKE POSITIVE ACTION

In the life cycle of the Ixodes ticks, leaf litter typical of a forest floor harbors the ticks during all four stages of their lives. In a forested residential area in New Jersey, raking up leaves in March and June reduced tick populations by 72 percent to 100 percent.

But woods need their leaf litter, and if you live near a large tract of forest, raking may be impractical, anyway. In this situation, it's better to maintain broad buffer zones that are mowed regularly, and to dress defensively (keep reading). Although ticks sometimes wander onto the edges of lawns, they are most likely to find you as you walk through tall grass or low shrubbery. Adult ticks crawl out to the tip of a blade or branch and wait for a potential host to happen by, a tick technique called "questing." Weld says nymphal ticks, which are responsible for 90 percent of Lyme disease cases, are found mostly on the ground. So, if you "stay on the path"—which is exactly what you should do when hiking in woods or fields where ticks are likely to be—you won't pick up as many.

How about encouraging natural predators? Unfortunately, ticks don't have many of the domestic variety. Some MOTHER EARTH NEWS readers report that their flocks of poultry, especially guinea fowl, have put big dents in tick populations, which echoes centuries-old folk wisdom (see "Go Ahead, Get Guineas," October/November 2003, and, at MOTHER'S Web site [ http://www.motherearthnews.com ] see "Poultry Pest Patrol Stories" under "Community").

But in the suburbs of the future, the tick's worst enemy may be fungi such as Metarhizium anisopliae and Beauveria bassiana, which are found in soils and leaf litter in the Northeast. These and other fungi weaken and kill black-legged ticks. In the wild, researcher Ostfeld says fewer than 5 percent of female ticks are infected with the Metarhizium fungus. He says he hopes dev eloping a way to produce the fungus so it can be dusted or sprayed will result in a good biocontrol method. If it works, using the fungus would be like using milky spore disease to control grubs in your lawn. Ostfeld says inoculating leaf litter with the fungus in fall, when adult ticks begin questing for hosts, would result in a fairly good reduction in the tick population. (Stay tuned.)

OF MICE AND DEER

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