Levin: Summer Tick Studies

Aug 30, 2017

Ticks move like zombies; one speed, one direction, a stiff, endless, methodical forward plod… best described as creepy.

Small spiders, on the other hand, the most likely beasts to be confused with ticks are all animation; scurrying and stopping, eight-legged, windup toys that feast on ticks as well as sundry other small things.

Decades ago, I’d remove one or two dog ticks from my collie each summer. Today, both my German shepherds have tested positive for Lyme disease, although both are asymptomatic. And, before I fitted them with repellant collars, I’d tweeze dozens of ticks off them from March to November, and I’d regularly vacuum engorged, Lima bean-shaped ticks off the floor, tiny legs sculling the air puppet-like in one of evolution’s great appendage-torso mismatches.

Lyndon State biologist Alan Giese is a specialist on the blacklegged tick, and when I asked him what accounts for the dramatic increase in both species and populations of ticks in northern New England, he answered unflinchingly, “Climate change.”

According to Giese, there’s been - and continues to be - a worldwide increase in ticks, spreading north, as well as into higher elevations.

With ticks comes disease: Rocky Mountain spotted fever; babesiosis, which has malaria-like symptoms; and Powassan, a virus infection that triggers encephalitis and averages seven reported cases each year, including a recent death in Saratoga. Anaplasmosis, is also transmitted by the bite of an infected blacklegged tick. It’s the second most common tick-borne disease in Vermont, with symptoms including headache, malaise, nausea, and confusion.

Twelve thousand cases of Lyme disease were reported to the Center for Disease Control in nineteen ninety five; that number jumped to forty thousand by twenty fifteen, although some epidemiologists claim the total’s closer to three hundred thousand, with most cases either going unreported or misdiagnosed.

Free range chickens eat lots of ticks; so do 'possums. But in twenty fourteen, biologists from the University of Maryland determined that since an adult male timber rattlesnake eats mostly small rodents and shrews – both principal reservoir hosts of Lyme disease – just one rattlesnake may consume nearly six thousand blacklegged ticks annually, of which an estimated twenty-eight hundred would likely carry Lyme disease.

And because a timber rattlesnake feeds only six to twenty times per summer, I wonder how many ticks a high-strung and perpetually hungry weasel, might remove.