How do you kill bedbugs without having to sleep in a bed full of pesticides at night? Impale the tiny buggers!
For centuries, eastern Europeans, before the widespread application of pesticides such as DDT, would scatter the leaves from kidney bean plants around their beds as traps. In the morning the leaves would be covered with red dots, where the microscopic hairs on the leaves would have hooked the legs of a bedbug, stopping the creature in its munching little tracks.
The folklore remedy would then have you burn the bug-encrusted greenery and reapply until the problem is gone. And while leaves on the floor is fine, sleeping with them in bed may result in an itch-factor that could be just as uncomfortable as the bites from the bugs.
Now that bedbugs have become resistant to pesticides — and other remedies such as freezing, extreme heating, and vacuuming are either expensive or unreliable — the old methods are being put to the scientific test under an electron microscope.
Bedbug locomotion specialist Catherine Loudon of the University of California, Irvine, is working with a team of entomologists to develop a synthetic mimic of the bean plant leaves. The hairs, known botanically as trichomes, on the leaves attack the bugs’ legs at their weakest points.
“The areas where they appear to be pierceable,” Loudon told the New York Times, “are not the legs themselves. It’s where they bend, where it’s thin. That’s where they get pierced.”
The team published their study of microfabricated materials that resemble the geometry of the hooking leaf hairs today in The Journal of the Royal Society Interface. But still, “the synthetic surfaces snag the bedbugs temporarily but do not yet stop them as effectively as real leaves,” they reported in a press release.
“Nature is a hard act to follow, but the benefits could be enormous,” reported co-author Michael Potter of the University of Kentucky. With the synthetic materials the bugs can walk 39 steps with only a momentary shake of the leg when snagged (view video here). The actual leaves not only snag put pierce the bug joints after only six steps (view video here).
The team plans to continue their efforts to make a better replacement to what nature currently provides. As they wrote in their study, “With bedbug populations skyrocketing throughout the world and resistance to pesticides widespread, bio-inspired microfabrication techniques have the potential to harness the bedbug-entrapping power of natural leaf surfaces.”
IMAGE: Bedbug (left) on bean leaf; and (right) a bedbug leg trapped by tiny, hairlike trichomes on a the leaf’s surface. (Megan Szyndler and Catherine Loudon / UC Irvine)