Fans of attractive legs will be glad to know that shorts are no longer part of my outdoor wardrobe, although I didn’t do it to hide my knobby knees.
I did it because of ticks.
In the mudroom of my house, I keep a pair of long pants, light-colored and lightweight and infused with permethrin, the most effective tick-killing chemical. Several companies sell such clothing.
Beginning as soon as the snow melted, every time I go out to do chores in the garden or the yard, or just stroll around the woods and fields, I change into those pants and tuck them into my socks.
If a tick grabs onto me as I walk past, the victim-seeking procedure entomologists call “questing,” hopefully it will die before it can crawl up to my waist and make it to my skin.
When I return home, I change back. When the pants get too grubby I wash them, but only once or twice a season to preserve the insecticide as long as I can; the pants aren’t cheap.
All this is a pain in the patoot, as my dad says, but it beats getting Lyme disease. Because the ticks are bad, as you know, and they and their blood-sucking brethren are only going to get worse.
“We should expect it to increase and the diversity of vector-borne disease to continue increasing in the future,” is how Matthew Ayres, a Dartmouth biology professor, put it when we chatted about this depressing topic last week.
I called Ayres, who is chairman of the graduate program in Ecology, Evolution, Ecosystems and Society, following a report from the federal Centers for Disease Control about “vector-borne disease,” meaning human ailments caused by microbes or pathogens transmitted by biting bugs.
The CDC report said cases of disease from mosquito, tick, and flea bites more than tripled throughout the U.S. from 2004 to 2016, with tick-borne diseases doubling.
But it’s not just the number of cases that is growing, CDC said. New diseases keep showing up, carried here by global commerce and travel or by pathogens and vectors expanding their range due to climate change.
The CDC said “seven new tickborne germs can infect people in the U.S.” now, compared to 2004. They include anaplasmosis/ehrlichiosis and babesiosis, which are often carried by the same ticks carrying Lyme, as well as the even scarier powassan virus, which is thankfully still rare here but probably won’t be for long.
“It sounds like a lot, and it is a lot. On the other hand, it’s not very surprising because we’re seeing the same thing happening in other kinds of systems. It’s a predictable consequence of a changing world,” Ayres said.
“In New England, forests are being filled with insects and pathogens that weren’t here 20 to 30 years ago. Agricultural systems all over the world continually experience new distribution, severity, frequency of pests – including fisheries, marine and estuary systems. There are just lots and lots of organisms whose distribution and abundance are changing.”
Okay, fair enough. But surely Ayres could counter this gloomy report with news that we will be saved by medicine (vaccines!) or biotech (gene drive and CRISPR will render bugs harmless!) or technology (I once wrote about a prototype tick-killing outdoor Roomba).
“I doubt it,” he said. To put it bluntly, we should realize that going outdoors in New England will carry this risk now and probably forever.
The one technical change that is likely to help, he said, is gathering more information and giving it to more people, more quickly.
“We could do so much better at monitoring the abundance and disease-carrying frequency of, for example, deer ticks in New Hampshire,” Ayres said.
Ayres has an undergraduate student gathering data on tick numbers in different environments to help develop such quantification.
With ticks, the risk changes based on the season – they’re hungrier right after winter, when babies (nymphs) are growing, and again in fall as they prepare for the next winter – and also based on hour-by-hour weather.
Ticks are flat with a high surface-to-volume ratio; as a result they desiccate easily. When it’s hot and dry they tend to hide from the sun, which makes it less likely they’ll grab us as we walk by. So if the morning is going to be sunny and dry, and it will cloud up in the afternoon, hiking in the morning is better in terms of ticks.
Making that sort of decision is part of what we’re all going to have to do in a changing worlds of vector-borne disease.
“More information is good because people don’t necessarily know. There are simple precautions that one can take that greatly reduce the risks,” Ayres said.
Long pants are part of it. Long sleeves, too, to keep away mosquitoes. A secondary benefit: They protect you from poison ivy, which has become more widespread as winters warm and slightly more toxic as carbon increases in the atmosphere, as well as protecting your from sunburn.
Wearing long clothing in summer might be yucky, but it means I can use less even-more-yucky sunscreen and bug spray.
I’m sure you already to search yourself for ticks after being outside, although it’s easier if you’re pale skinned and have a partner to check your back.
This has some limits: Deer ticks are small and their nymphs are tiny, almost impossible to spot. But keep trying.
There are also some ways to reduce the chance that ticks are in your yard:
You can hire companies to spray your yard, although be careful: This is bad for bees and other pollinators. The good companies usually limit it to “barrier spray” procedure, where the woods or tall-grass fields meet your lawn, creating a chemical barrier to keep ticks from getting closer.
You can buy or build some “tick boxes” or “tick tubes,” filled with permethrin-infused material that kills ticks on the mice that get attracted to the box. Mice are the most common way that ticks get carried around our yards.
You can even buy some chickens or guinea hens, which eat ticks, and let them roam. Be warned, however: guinea hens are a vocal nuisance and chickens are more work than you might think.
As I said, none of these are perfect. You will still need to search yourself and dress appropriately, and accept that this is part of the new reality.
We’re living in a different world these days, but we can’t let it keep us from the joys of enjoying the New England outdoors. Even if it means nobody gets to admire my knees.
(David Brooks can be reached at 369-3313 or dbrooks@cmonitor.com or on Twitter @GraniteGeek.)
