Some memes never die, as long as there are bloggers to keep them alive. Each summer, the first faint hum of a mosquito at the window screen reminds some right-wing think-tanker to blame the Environmental Protection Agency for banning DDT (and calls forth a response from the left, blaming global warming). In fact, DDT is still being used, mostly in Africa and Asia, to control malaria, something even some environmentalists have reluctantly endorsed. But it remains a touchstone in the never-ending struggle over government regulation—one of the first and most visible instances of a chemical banned over its long-term environmental effects. For environmentalists it is a symbol of success, and for industry apologists, a shameful example of shoddy sentimentalism influencing policy. A slick Web site called Rachel Was Wrong—run by the libertarian-oriented Competitive Enterprise Institute—exists entirely to dispute the founding document of modern environmentalism, Rachel Carson’s Silent Spring. So it was probably inevitable that the latest plague to be visited on innocent Americans’ hides—bedbugs—would be enlisted in the campaign to bring back DDT.
This represents an unusually pure example of right-wing ideology, because it is almost completely divorced from any real-world considerations of either environmentalism or entomology. There is virtually no demand, including from the pest-control industry, to bring back DDT to use against bedbugs, and widespread agreement that, environmental concerns aside, it wouldn’t work.
DDT “devastated” bedbug populations when it was introduced in the 1940s, says Richard Cooper, technical director for Cooper Pest Solutions and a widely quoted authority on bedbug control. Mattresses were soaked in it, wallpaper came pre-treated with it. It also killed boll weevils, which fed on cotton buds and flowers (by far, the majority of DDT was applied to cotton fields), and, incidentally, it killed bald eagles and numerous other species of birds, the phenomenon that gave Carson her title. In the laboratory, DDT can cause cancer in animals; its effect on human beings has long been debated, but since it accumulates up the food chain, and stays in the body for years, the consensus among public-health experts was that it was better to act before effects showed up in the population. But long before the United States banned most uses of it in 1972, DDT had lost its effectiveness against bedbugs—which, like many fast-breeding insects, are extremely adept at evolving resistance to pesticides. “Bloggers talk about bringing back DDT,” says Bob Rosenberg, director of government affairs for the National Pest Management Association, “but we had stopped using it even before 1972.”
Nor is there any reason to think it would work better today; according to Jody Gangloff-Kaufmann, an urban entomologist at Cornell, among a wide variety of pesticides tested against bedbugs within the last two years, DDT performed the worst. In the 1960s and 1970s, most of the bedbugs that had survived the onslaught of DDT were wiped out by malathion, until it, too, stopped working, and the same thing happened with a class of chemicals called pyrethroids. Diazinon was effective against the remaining population, but it was banned for indoor use in 2002; it’s not clear how effective it would be today. “What we’d like is something that you can spray on the floor and two months later a bug will pick up a lethal dose from walking across it,” says Dini Miller, a Virginia Tech entomologist and one of a very few academic experts on bedbugs. “It doesn’t exist. Most of the things we have now, you almost have to spray directly on the bug to do anything to him. Or hit him with the can.”
The one thing that demonstrably does work is a pesticide called propoxur, but in 2007, when the EPA asked the manufacturer for more safety data—which would have cost millions of dollars to compile—it was pulled from the residential market instead. The main safety concerns involve young children; it is still registered for nonhousehold uses. Last year the state of Ohio petitioned EPA for an emergency exemption from the ban. In a letter to Gov. Ted Strickland this spring, EPA administrator Lisa Jackson said the request “presents an unacceptable risk to children who might be exposed to propoxur,” but an EPA spokesman says the agency is still “evaluating whether propoxur could be approved for emergency use with additional restrictions to ensure children are not exposed to the pesticide residues after applications.”
So leaving DDT out of it, you could, if you choose, blame overzealous regulators for allowing bedbugs to creep back into American mattresses—although as a political matter, you face the awkward fact that several of the key decisions, in 2002 and 2007, were taken under the auspices of the famously antiregulatory Bush administration. But it’s beside the point at best, says Cooper, who, like most pest-control experts, thinks there’s no single cause for the bugs’ resurgence. Biological resistance, complacency (especially in the hotel industry), changes in pest-control practices favoring baiting over spraying, and an increase in international travel all played a role, but for whatever reasons, the problem is with us now, and likely to remain. The EPA is considering, and has promised to expedite, new pesticide registrations for bedbugs, but these are all existing chemicals already being used for something else, sometimes in different combinations or concentrations. There are no new chemicals in the pipeline, and, as Miller points out, companies looking at a 10-year testing and approval process costing as much as $200 million aren’t lining up to produce one. The big profits in pesticides are in crops and lawns, and research money, such as it is, mostly goes to mosquitoes. Bedbugs suffer—or, from their point of view, benefit—from the fact that they are merely household pests and don’t transmit disease. Miller, in jest, says she sometimes wishes they did.
But bedbugs can be tormenting to people afflicted with them, and people sometimes do extreme things to get rid of them—such as setting off dozens of insect bombs in a room, which can be quite effective if the house blows up as a result. The one thing we can be certain won’t work is bringing back DDT—and for that, at least, the bald eagle can be grateful.