Levin: Living Among Blacklegged Ticks

Jul 26, 2017

Sitting on my desk at home is a small vial of alcohol containing three pickled, blacklegged tick nymphs, each no bigger than the period at the end of a typed sentence… three tiny alarming arachnids.

They were given to me by Alan Giese, a specialist who previously studied owls and later the genetic diversity of fish, but switched to blacklegged ticks seven years ago when Lyndon State College hired him as an associate professor of biology.

Blacklegged ticks – also called deer ticks - host and transmit a number of serious microbial diseases, including Lyme disease, anaplasmosis, and babesiosis. And they thrive in the mixed woods of our region.

It’s disconcerting to say the least, to realize that Vermont and New Hampshire have one of the highest rates of Lyme disease per capita in the country, but if we truly understand the tick biology, some of that fear is alleviated, thus reserving the worst of our primal and irrational fears for snakes, sharks, and spiders.

On a recent July morning, I joined Giese for some fieldwork in a public recreation area that borders both the popular Union Village Dam and Thetford Academy.

I already knew that mother ticks do not pass disease into their eggs; Larva are born clean and only later pick up Lyme disease from feeding on the infected blood of white-footed mice and chipmunks; but only the nymphs pass the disease directly to us.

I learned from Giese that spraying pesticides around the yard may have the unintended consequence of killing spiders, a principal predator of the blacklegged tick. Then ground-feeding birds like robins and hermit thrushes unknowingly carry ticks into your property long before the spiders recover.

Desiccation also kills blacklegged ticks, which is why they avoid pine forests and on sweltering summer days retreat under moist woodland leaf litter by midday. On wet or overcast days, however, they may be active all day. Blacklegged ticks rarely turn up on lawns and uncut meadows – which is home to the bigger, thicker dog tick.

The most reassuring news was that Giese has never suffer bouts of Lyme disease… NONE. He’s never even been bitten. He always carries a change of clothes in his truck and then cooks his field clothes in the car-carrier or at home in the drier for ten minutes. A rough washcloth removes embedded nymphs, which swirl down the drain like so many flecks of dirt.