Unnatural Selection

“I was so sleep deprived from worrying and from the itching, I was literally going crazy,” recalls Abby of her bout with bedbugs. “The bites were in rows: breakfast, lunch, and dinner. They were terrible bites that itched like nothing before.” Desperate for relief, Abby took to sleeping on an air mattress in the middle of the kitchen floor. She’d hoped the problem was fleas, possibly brought in by the cats—at least fleas are easy to kill. But that wasn’t the problem. It was bedbugs, which, says Abby, are endemic in town. As a physician and director of a local community health center, she ought to know. She’s since seen plenty of bedbug bites and plenty of denial. Abby suspects that, for years, patients with oozy welts caused by bedbugs were misdiagnosed by physicians and nurse practitioners as scabies or flea bites—both easier problems to remedy. The real cause was overlooked for good reason. Like once-common diseases, bedbugs had become part of our history, banished from our homes and apartments decades ago. But now they are back with a vengeance. Pest-management professionals like Orkin and Terminix publish an annual list of top bedbug cities. In 2012, Philadelphia topped the Terminix list, while Chicago topped Orkin’s. Reported infestations have risen dramatically over the last two decades. In their 2013 survey Bugs without Borders, the National Pest Management Association reports that nearly 100 percent of the pest-management companies surveyed had been called upon to deal with the bugs, up a few percentage points from previous years and far more than a decade ago. And there is no end in sight.

On a cold Wednesday evening after a presentation on pollution and evolution at Boston’s Arnold Arboretum, I was asked a question I’ve struggled with ever since I began thinking about toxicants and evolution. I’d just rattled off a list of synthetic chemicals that are now part of our chemical environment: plastics, pesticides, flame retardants, PCBs. Usually after a presentation, the discussion revolves around how we can do better: improve toxicity testing, regulation, and management, or rely on green chemistry to create less harmful chemicals. But this time, perhaps making a bit of mischief, an audience member asked, “If we can’t rein in these chemicals, why bother? Why not let nature take its course? You know, survival of the fittest?”