Gardeners may not have heard much about ‘deer ticks’ lately, but an expert will tell the Woody Plant Conference on July 18 that the ticks are increasing their range in Pennsylvania. Also on the agenda for the conference at Scott Arboretum is Roy Lancaster, author of 'Travels in China – A Plantsman's Paradise.'

No News Isn’t Necessarily Good News When It Comes to Lyme Disease

By Denise Cowie

www.GreaterPhiladelphiaGardens.org

Ilene Sternberg has a pretty large garden in West Chester. She also has a couple of increasingly arthritic knees that make it difficult for her to get up and down as easily as she once did to weed and perform other gardening chores.

But, she jokes, if an army can travel on its stomach, she can certainly garden on hers. And she does, tossing a cushion from outdoor furniture onto the ground and draping herself across it so she can get up close and personal with her plants.

All this is necessary because she shares her garden – reluctantly – with some hungry suburban deer, despite having no woods around her property. “I live in a typical suburban development with lots of open space where the deer and the buffalo roam,” she says.

With the deer have come the so-called deer ticks – more accurately blacklegged ticks – and with the ticks comes the potential for Lyme disease.

For the fourth time in the last eight years or so, Sternberg is on antibiotic treatment for Lyme disease. And the infection, she says, “exacerbates all the arthritic symptoms, which I have in my hands, hips, and feet, as well as the knees.”

Several of her gardening friends are in the same boat, being treated for second or third bouts with Lyme.

That’s not abnormal, according to Steve Jacobs, who has been involved with urban/public health entomology for more than 30 years, and has been the urban extension entomologist for the Penn State Department of Entomology for the last two decades.

“People can get repeated infections,” says Jacobs, who’ll talk about “Lyme Disease in Pennsylvania” at the annual Woody Plants Conference at Scott Arboretum of Swarthmore College on July 18. Not only is there no vaccine to immunize people against the disease, but no immunity develops in those who have contracted it.

Jacobs is among a handful of high-profile speakers who will address the day-long conference on topics ranging from Creating Landscapes with Roses and Trees and Shrubs of Distinction to preparing for a plant collecting expedition. Internationally acclaimed plantsman and author Roy Lancaster will also share reflections on his life of travel to see plants in the wild and in cultivation.

Jacobs’ talk will focus not on plants but on the outdoor environment where plantsmen spend much of their time. Not that gardeners are any more at risk of getting bitten by deer ticks than anyone else who spends time outdoors, of course.

“It is believed that the majority of people who get Lyme disease get it in their back yards,” says Jacobs.

In 1990, Jacobs received a cooperative agreement from the Centers for Disease Control to survey the ticks of Pennsylvania and to produce Lyme disease educational materials for the healthcare community and the general public.

Among his findings is that the tick responsible for Lyme disease is increasing its range in Pennsylvania.

“We are starting to see them just about everywhere in the state, and where we have seen them, they are increasing [in numbers],” says Jacobs. “They are coming on strong.”

Blacklegged ticks infest deer, various species of mice, and other rodents, including chipmunks. Although you’re most likely to encounter the ticks in the woods, you may find them in pockets almost anywhere – in rural areas, in the suburbs, or even in urban areas where there are parks.

The trend over the last 20 years has been for more reported cases of the disease, with an average 4,000 cases a year documented in Pennsylvania over the last five years, Jacobs says. Yet the problem rarely makes the news anymore.

That’s not a good thing. People need to be reminded about tick-borne diseases for their own safety, and a little publicity could persuade politicians to fund research in this area.

Although the Lyme problem is increasing, there are some things that can be done to help combat it – though not by individual homeowners, says Jacobs. Large-scale efforts could involve anything from controlling the deer and rodent populations to applying chemicals to the habitat.

So what can individuals do? Use a repellent containing DEET if you’re going to be in a potentially tick-infested area, says Jacobs. “Spray your clothing and shoes, but follow the label instructions – that’s our mantra here. Some fabrics don’t like to be sprayed with DEET products that contain alcohol.”

Wear light-colored clothing outdoors so it will be easier to spot the dark ticks, and check carefully for ticks before you go back inside. Check your pets, too, especially dogs, which can get serious cases of Lyme disease.

Jacobs doesn’t have much faith in the often-suggested idea of covering every inch of skin and pulling your socks up over your pant-legs when you go outdoors: “If you stretch your socks out over your pants, there are fairly large holes in the knit that the ticks could get through.”

And don’t think that only pinhead-size ticks transmit Lyme. The blacklegged tick has four stages – egg, larval, nymphal and adult – and each stage is approximately twice the size of that preceding it, says Jacobs. The adult blacklegged tick is only slightly smaller than a so-called dog tick, he says, “so this idea that it is tiny is dangerous. If you get any kind of a tick on you, you should have it identified, unless you are absolutely sure of the identity.”

The peak period for tick activity is usually the first couple of weeks in June. That’s when the nymphs are out, and a lot of people are out in the woods or their gardens. Most Lyme disease cases occur from May through July, Jacobs says.

But you’re not entirely safe, even in winter.

Jacobs cites research that has shown that deer ticks can be active at temperatures as low as 28 degrees Fahrenheit, as long as there is no snow on the ground.

“People don’t think they can do that in the winter,” he says, “but if there is no snow, adult-stage ticks will come out of that leaf litter in the forest.”