Bed bugs are notoriously tough to exterminate—many populations have already evolved resistance to common insecticides. But they do have a non-chemical enemy: kidney bean leaves.
The leaves' microscopic hairs pierce the bugs' feet, trapping them after just a few six-legged steps. It's a traditional anti-bed bug measure in the Balkans [See Michael F. Potter, The History of Bed Bug Management, in American Entomologist]. And tests have shown the leaves to be remarkably effective, but only when freshly picked—meaning it's not the most practical tactic for city dwellers.
So researchers tried a synthetic alternative. They created molds of the leaves, and cast 158 replicas using various plant-like polymers. The synthetic leaf surfaces looked identical to the real leaves, each sporting tens of thousands of sharp, hooked hairs. But they didn't impale or trap bed bugs in the lab—they just snagged them momentarily, delaying their march toward blood. Those results appear in the Journal of the Royal Society Interface. [Megan W. Szyndler et al., Entrapment of bed bugs by leaf trichomes inspires microfabrication of biomimetic surfaces for pest control]
The researchers are still hunting for the bean leaves' secret. If they discover it, they say it could be a nifty way to treat infestations without pesticides. As long as the thought of all those bloodsuckers trapped and squirming under your bed won't bug you all night.
[The above text is a transcript of this podcast.]