By Dan Rahn
University of Georgia
"Tick numbers are highest from March through September, but there is no month when ticks aren't active in Clarke County," said Nancy Hinkle, an entomologist with the University of Georgia College of Agricultural and Environmental Sciences.
Hinkle recently completed a study of the tick population in a single Clarke County, Ga., site. She visited the site once a month and collected ticks that attached to a drag cloth, a standard tick collection method.
In the three-year survey, the lone star tick was the most commonly found, with 59 percent of the total. American dog ticks made up 37 percent. The only other ticks were rare, with Gulf Coast ticks accounting for 2.5 percent and black-legged ticks only 1 percent.
Numbers vary
"That population is fairly typical of the Athens area," said Lance Durden, an assistant professor of biology at Georgia Southern University. "If you go down into the barrier islands, you'd find a much higher prevalence of black-legged ticks."Black-legged ticks, or deer ticks, can carry Lyme disease, Hinkle said. And Hinkle found just four black-legged ticks in three years in Clarke County. But the good news there isn't so bright farther south.
"We could probably go out right now in Bulloch County and find 50 to 100," Durden said in mid-February. "And we'd find even more closer to the coast."
Black-legged ticks live throughout Georgia. "But they're much more common along the coast," Durden said. "And they're almost absent in the mountains."
Mountain don't
They're more likely to thrive where the humidity is higher, he said. "I know it can be humid in the mountains," he said. "But we don't see the black-legged tick very much there."Weather affects the proportions of tick species, too. Lone star tick numbers rise during warmer weather, Durden said. Adult black-legged tick numbers climb in colder weather.
Georgia has one or two species of soft ticks, which live in bat roosts or animal burrows, and perhaps 20 species of hard ticks. "There may be one or two others we don't know about," Durden said. Of the hard ticks, most are found only on wildlife.
The four species Hinkle found in her study are all "questing" hard ticks. They climb up on plants and use the hooks on the tips of their legs to hook onto animals (or humans) passing by. Then they dig in, feeding on the host's blood.
Hinkle and Durden both say ticks can do that year-round because they "hunker down" in the leaf litter to survive Georgia's brief freezes. As each day warms up, they climb back up for more questing.
Just your luck
People are chance hosts for ticks, Hinkle said. The ticks quest for wildlife, but sometimes people pass by, too. If all of the people disappeared, she said, "the ticks would still be just fine."Low black-legged tick numbers in any area don't mean the ticks there can't make you sick. American dog ticks can carry Rocky Mountain spotted fever. Lone star ticks and black-legged ticks both can carry human ehrlichiosis, a family of sometimes deadly tick-borne diseases with a range of flu-like symptoms.
If you develop a rash or unexplained flu-like symptoms, Hinkle said, advise your physician of any recent tick exposure.
In general, she said, ticks have to be attached to their host for at least 24 hours to successfully transmit disease organisms. "So daily 'tick checks' are the most effective means of protecting yourself and your pets from tick-borne diseases," she said.
Is it more important to be careful of ticks in certain areas?
"Well, anywhere you go, you'll find ticks," Durden said. "There are even ticks in the oceans, on sea snakes."
(Dan Rahn is a news editor with the University of Georgia College of Agricultural and Environmental Sciences.)
