Here's some bad news for anyone who lives by the credo the only good bedbug is a dead bedbug: The nocturnal bloodsuckers that infest homes, hotel rooms, and even movie theaters are getting harder to kill. In a study in the Journal of Medical Entomology, researchers say that bedbugs collected from Cincinnati and Michigan—where a man recently lit himself on fire in his quest to vanquish the pests—showed "dramatic levels of resistance" to the most commonly used insecticide in the world, the BBC reports. Lead researcher Alvaro Romero of New Mexico State University says the results don't necessarily mean that bedbugs worldwide are resistant to neonicotinoid insecticides, but they suggest that using chemicals to control bedbugs is a losing strategy in the long run. "It's a very complex problem," Romero says. "We need to incorporate other alternatives."
Those include heat and vapor treatments, and enclosing mattresses in bed bug encasements, he says. In the experiment, researchers compared bedbugs that came from homes treated with neonics to bedbugs from a colony with no such exposure. It took just 0.3 nanograms of insecticide to kill half the insects in the latter group, but 10,000 nanograms were required for the other. Simply put: "People are spending a lot of money on products that aren't working," says researcher Troy Anderson at Phys.org. A separate study found that bedbugs that take a "blood meal" after an insecticide treatment are more likely to survive at least long enough to reproduce—a factor for which laboratory testing of insecticides fails to account, according to a post at Eureka Alert. "Many of the insecticides labeled for bedbug control may not be as effective as claimed, because of the inadequate testing method," a researcher says. (At least bedbugs won't give you Lyme disease, unlike these ticks that now infest half of US counties.)