Bean leaves may inspire remedy for bedbugs

Microscopic hairs on the leaves of kidney beans may serve as a model for a future remedy for bedbugs, according to findings from a recent study.

In eastern Europe, a centuries-old folk remedy for bedbugs had involved using the leaves of bean plants to trap and then destroy the pests, according to researchers with the University of California, Irvine and the University of Kentucky.

“This purely physical entrapment was related to microscopic hooked hairs (trichomes) on the leaf surfaces,” the study authors noted.

Investigators used videography and scanning electron microscopy to document this trapping mechanism, which resulted in the bedbugs’ feet becoming impaled by the trichomes.

“Struggling, trapped bedbugs are impaled by trichomes on several legs and are unable to free themselves. Only specific, mechanically vulnerable locations on the bug tarsi (feet) are pierced by the trichomes, which are located at effective heights and orientations for bedbug entrapment despite a lack of evolutionary association,” the authors stated.

Using this information, the researchers created microfabricated surfaces that were “indistinguishable in geometry” from the plant’s real leaves. They used polymers containing material properties that are similar to plant cell walls.

“These synthetic surfaces snag the bedbugs temporarily, but do not hinder their locomotion as effectively as real leaves,” authors wrote.

Eventually, synthetic materials could be a nontoxic alternative to pesticides to eliminate bedbugs.

“Modern scientific techniques let us fabricate materials at a microscopic level, with the potential to ‘not let the bedbugs bite’ without pesticides,” lead author Catherine Loudon stated in a news release.

The findings were published online in the Journal of the Royal Society Interface.