Thanks, Holly Gaff. Soon, anyone straining to tweeze off a mid-back tick can find answers to the obvious question: What if humankind just went after the little bloodsuckers with killer robots?
Gaff, who calls herself a mathematical ecoepidemiologist, at Old Dominion University in Norfolk, Va., is one of the few people collecting real field data on the efficacy of tick-slaying robots. This summer, she’s been supervising a field test of a terminator named TickBot deployed to try making mowed grass safe for children. Researchers will start analyzing results in early fall.
Ticks make formidable enemies. “Almost every control measure that has been tried has failed, and has failed miserably,” Gaff says. “We are slowly coming to embrace the fact that you cannot eradicate ticks.” What human ingenuity might do, however, is manage the risks and — dream big! — make ticks irrelevant.
That’s an urgent hope. Data from the Cary Institute of Ecosystem Studies in Millbrook, N.Y., have for two years suggested 2017 will be a high risk one for Lyme disease in the Northeastern United States. Of the various illnesses that North America’s ticks pass along, Lyme is the most common, caused by a squiggle of a parasite called Borrelia burgdorferi. The disease can bring on an eerie red bull’s-eye rash, flulike misery and risks of long-term neurological and joint troubles if not treated early. In 2015, the U.S. Centers for Disease Control and Prevention tallied about 30,000 confirmed cases. Considering gaps in case reporting, some estimates put the number closer to several hundred thousand.
So bring on the robots and other science revenge fantasies. It’s time to rethink humankind’s defenses against ticks. Pesticides and tick checks just aren’t doing the trick.
There may be ways to attack ticks without touching a single molecule of their die-hard little bodies. Ecologists have made progress in tracing what ticks need from the woods and lawns where they lurk. For instance, researchers believe that it was a bumper crop of acorns in 2015 that, through a Rube Goldberg series of consequences, created conditions for a perfect tick storm two years later. Breaking key ecological connections could knock back the tick menace in the future.
Molecular biologists are focusing on tick survival tricks. Researchers are looking for weak spots inside tick guts and trying to take advantage of ticks’ reckless abandon in mating. Biology is proving as important as electronics in the robot line of defense.
Ticks attack
First, a quick intro to ticks.
Unlike mosquitoes, ticks are pure vampires, consuming nothing but blood. Mosquitoes get colloquially called vampires, but blood is just their version of a pregnancy craving, a female-only nutrient gorge to aid reproduction in an adult life of sipping flower nectar.
For most of the troublesome tick species in North America, including the black-legged ticks that spread Lyme, blood is the elixir that lets them transition to the next life stage — from larva to nymph to adult. And after a single meal, an adult female can lay 1,000 or even 15,000 eggs without anything else to eat for the rest of her life. Hard ticks, the Ixodidae family, which includes the black-legged variety, typically have only two or three meals of any kind during the entire two or three years they live.
Soft ticks are gluttons, relatively speaking. Many move into mammal dens for a bedbug lifestyle. These ticks hide and, whenever they get hungry, just crawl over to the resident dinner.
For ticks without live-in prey, many “quest,” as the ambush is called. Ticks climb to some promising spot like the top of a grass blade, raise their front legs and just wait until something brushes by. But there are also ticks that hunt vigorously, even pursuing human prey.
A visit to Dennis Bente at the University of Texas Medical Branch in Galveston is unforgettable, in part because of a video of a Hyalomma tick chasing down one of Bente’s collaborators. The tiny brown creature scurries like a frantic ant in an almost-straight line over bare dirt, onto a boot and finally into a hand reaching down to grab it. This hunter doesn’t live in North America.
Ticks can spread a wide variety of diseases. Despite its name, Rocky Mountain spotted fever, which brings a higher risk of fatality than Lyme, is more common in the central United States and the South than in the Rockies. Other tickborne diseases are lately getting attention: A tick-bitten baby in Connecticut in April became the state’s first reported victim of the rare, but potentially fatal Powassan virus, thought to enter the bloodstream in just 15 minutes after a tick starts feeding. And medical journals are publishing discussions of whether a tick bite might lead to a sudden, deadly allergy to red meat. With a possible threat even to our beloved hamburger, new approaches to fending off ticks can’t come soon enough.
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