New technology based on old Balkan bed bug remedy

by nobugsonme on April 10, 2013 · 18 comments


UCI image of bed bug on kidney bean leafBedbug on bean leaf (left); bedbug leg trapped by tiny, hairlike trichomes on leaf surface (right)

Image credit: M. Szyndler and C. Loudon / UC Irvine

Researchers have investigated an old Balkan bed bug remedy, finding that kidney bean leaves can impale and trap bed bugs.  The scientists, Catherine Loudon, Robert Corn, and Megan Szyndler of The University of California-Irvine and Michael Potter and Kenneth Haynes of the University of Kentucky, are now working on synthetic materials which can do the same thing.

A University of California Irvine press release notes,

Their work was motivated by a centuries-old remedy for bedbugs used in Bulgaria, Serbia and other southeast European countries. Kidney bean leaves were strewn on the floor next to beds and seemed to ensnare the blood-seeking parasites on their nightly forays. The bug-encrusted greenery was burned the next morning to exterminate the insects.

Through painstaking detective work, the scientists discovered that the creatures are trapped within seconds of stepping on a leaf, their legs impaled by microscopic hooked hairs known botanically as trichomes.

Using the bean leaves as templates, the researchers have microfabricated materials that closely resemble them geometrically. The synthetic surfaces snag the bedbugs temporarily but do not yet stop them as effectively as real leaves, Loudon said, suggesting that crucial mechanics of the trichomes still need to be determined.

Theoretically, bean leaves could be used for pest control, but they dry out and don’t last very long. They also can’t easily be applied to locations other than a floor. Synthetic materials could provide a nontoxic alternative.

The study, “Entrapment of bed bugs by leaf trichomes inspires microfabrication of biomimetic surfaces” has been published in the latest issue of the  Journal of the Royal Society Interface (abstract).

How did the record of the folk bed bug remedy travel to modern researchers?

According to the New York Times,

This folk remedy from the Balkans was never entirely forgotten. A German entomologist wrote about it in 1927, a scientist at the United States Department of Agriculture mentioned it in a paper in 1943, and it can be found in Web searches about bedbugs and bean plants.

The New York Times also describes how the researchers uncovered the beautiful workings of the kidney bean leaves:

The first task was to determine exactly how the hooks — the technical name is trichomes — worked. The process was viewed through an electron microscope, Dr. Loudon said. “The foot comes down onto the surface, but as it’s lifting up, it’s catching on these hooks,” she said. “The point is pointing down. So all of their legs get impaled.”

“And as soon as one leg gets caught,” she added, “they are rapidly moving legs around and try to get away on the surface. That’s when they get multiply impaled.”

The team is now working on synthetic material to mimic the way the leaves work.  Brooke Borel has an interesting study in Popular Science of the mechanics of the kidney bean leaf “traps”.

It remains to be seen whether or how this technology will change bed bug treatment protocols.  (Of course, it’s been patented and has already been optioned by an as-yet-unnamed company.)

An obvious use which comes to mind is a form of bed isolation — where bed bugs had to climb over a synthetic bean leaf-like material in order to get to sleeping humans.

I have to say, the Balkan cure is a lot more promising than the Ancient Hungarian Bed Bug Curse.

Here’s a video showing a bed bug getting impaled and entrapped on the kidney bean leaf (because if we know our readers, we know they really like to see bed bugs get impaled, on anything):


Update (4/15): the article “Entrapment of bed bugs by leaf trichomes inspires microfabrication
of biomimetic surfaces” is currently available for free (full-text) via the journal’s website.

1 Ci Lecto April 10, 2013 at 9:27 am

A trap like this looks promising, but in a way, it’s not that different from a glue trap or a climb up (though it offers a lot more flexibility in placement). It also raises the question of “alarm pheromones”, that bed bugs allegedly give off when in distress. Experts cite “alarm pheromones” as a reason glue traps may not be a good idea (and why passives or the non-injurious “climb-ups” are a better approach). Will trapped bed bugs warn off their cohorts by shooting off alarm pheromones.

2 Ci Lecto April 10, 2013 at 9:33 am

Anyone recall the last time Popular Science heralded a “bed bug breakthrough”?

3 Brooke Borel April 10, 2013 at 12:54 pm

Hi Ci Lecto,

Brooke Borel here, author of both the bean leaf story and the bed bug sniffer story. For the record on the latter piece: I am well aware of the problems that both consumers and professionals have had with that product, and I have been actively working for about a year and a half to sort it out. You’ll note that Popular Science added an update to the story last September (see the end of the online version:, which went up within days of learning of specific tests that suggested the product doesn’t work. I have been waiting for the newest version of the sniffer for independent testing since March 2012. Until I get it, and if I get it, there is not much else I can do other than to point you to the last update on the article.

I’d hesitate to put the bean leaf work in the same category, since it is basic research and was peer-reviewed.


4 nobugsonme April 10, 2013 at 1:32 pm

Hi Brooke,
Good to see you here. Thanks for responding to Ci’s comments!

About the Goggin device,

Ci Lecto asked some good questions in the original PopSci post about the device here:

He wrote, in part,

Was this award given for a device that was convincingly demonstrated to expert judges to work? Or, is Popular Science going on the inventor’s statement? Or, is the award for “concept”?

A lot of us shared this concern that Popular Science was apparently giving an award without verifying the product did as it claimed.

The update is appreciated but given the “wild west” mentality that pervades the bed bug product industry, most of us are very skeptical about product claims and would never assume a product works until it has gone through rigorous testing, or has at least been used by lots of consumers and PMPs.

As for the study of kidney bean leaves, the results of the study are of course reliable. What products this may lead to, or their value, is still up in the air.

Having a reliable material for isolating a bed may have some value, but isolating the bed is controversial for the reasons Ci states and others. Some experts note it may cause bed bugs to spread to other areas, making them hard to treat.

That said, I’m of the opinion that the more information and options we have, the better, so in that sense, this could lead to helpful tools. It certainly can’t hurt.

5 nobugsonme April 10, 2013 at 2:40 pm

Canuck also drew our attention here to the Fiber Trap, another patented technology which mimics a spider web:

(I didn’t watch the entire video — a few minutes gives you the basic idea. If it doesn’t load, watch it here.)

Note this press release claims Fiber Trap has been tested by the Materials Science & Engineering Lab at SUNY Stony Brook University but there does not appear to be a peer-reviewed research study and it’s not clear if any entomologists have been involved with the design or testing. None is listed on the Fiber Trap company’s management page.

6 Brooke Borel April 10, 2013 at 3:15 pm

I can’t comment on Popular Science’s selection process. I’m not directly employed by them– I am a freelancer who writes for them, and I was not part of the Invention Awards selection team. But, it’s my understanding that there is a new vetting system in place for stories like this. And, of course, any time a story I’ve written says something that turns out not to be accurate, I will follow up on it. In this case, the reports trickled in slowly (directly to me, anyway), and it has thus taken a long time to clear up. My hope is to actually get the unit and have it tested and write up the results.

You also have to understand that once a story is published–even stories that are well intended but turn out to be wrong–there is not much you can do other than print a correction. You can’t take the story down, because you can’t erase the record like that. It’s out there already. Did that story make me wary of writing about specific products? Yes. Have I turned down several email, Twitter and other requests to write about other people’s products because of it? Absolutely.

As for the bean leaves, my story doesn’t say that the imitation leaves will definitely turn into a viable product. A lot of attempts at biomimicry fail, because we just aren’t able to replicate the original well enough. And, truthfully, I’m more interested in how the researchers used modern technologies to explore a very old remedy.

7 Brooke Borel April 10, 2013 at 3:24 pm

Also, one last thought: You also have to understand that, as a writer, I get all kinds of crank emails, comments, and letters from all kinds of people. Some insult my writing, some say I’m wrong when I’m right, others point out times I’m wrong when I’m wrong, some are long manifestos single-spaced and double-sided that come in the mail and reference dark matter and Jesus in the same sentence (yes, really). It takes awhile to sort out which are real and which are crazy, as well as which I should respond to and which I should ignore. So, I do take the comments about the sniffer seriously, and I am trying to follow up on it, but for these reasons: it took awhile.

8 TAOT April 10, 2013 at 3:37 pm

Brooke, I was in journalism major. My sophmore year, feedback was I was too nice and too sensitive to be a journalist. You have a hard job, and it’s really appreciated that you commented here.

9 Ci Lecto April 11, 2013 at 7:55 am


I’m thrilled to see you participating in this discussion, giving us a peek behind the curtain of the work you do…and that you’re continuing to write about bed bugs.

All the best,


10 BBStalker April 11, 2013 at 12:03 pm

I read this article in the NY Times the other day. My first thought is why don’t we just use the bean leaves instead of trying to create synthetic material that mimics it?

11 nobugsonme April 11, 2013 at 4:22 pm

Hi Brooke,

No, I do appreciate how difficult it is and I understand. And I get a certain amount of those kinds of emails too — though on a much smaller scale, I’m sure.

As Cilecto said, it’s great to have you participating here.

12 nobugsonme April 11, 2013 at 4:26 pm

BBStalker, this is explained in the article above. I cited the press release from UC-I:

“Theoretically, bean leaves could be used for pest control, but they dry out and don’t last very long. They also can’t easily be applied to locations other than a floor. Synthetic materials could provide a nontoxic alternative.”

They don’t last long and there may be ways of implementing a synthetic technology where heaps of leaves would not work well.

I am envisioning an encasement or Tyvek suit made with such a material, for use during bed bug treatment. The former idea isn’t ready for prime time (I mean, what do you DO after your encasement becomes covered in impaled bed bug carcasses?) The latter idea might not be too, too crazy. People with bed bugs have slept in stranger things.

13 Doug Summers MS April 12, 2013 at 9:28 pm

Here is a link to the bean plant story in Huff Post…

The 2nd slideshow at the bottom of the article has an interesting collection of short videos about bed bug related topics… Lou is featured in some of them

14 nobugsonme April 16, 2013 at 1:17 am

Update (4/15): the article “Entrapment of bed bugs by leaf trichomes inspires microfabrication of biomimetic surfaces” is currently available for free (full-text) via the journal’s website.

15 SandersC April 18, 2013 at 12:21 pm

Some folks are trying to sell these leaves at and
People have pointed out their limitations, but still think it might be interesting

16 nobugsonme April 18, 2013 at 10:47 pm

Yes, SandersC, coincidentally, I heard yesterday by email from someone behind He writes that he will begin selling fresh kidney bean leaves if 1000 people express interest in the product.

The thing is, this is a barrier method. If you have bed bugs already, they are probably harboring in, on, or near the bed. If they’re in it or on it, they won’t need to cross kidney bean leaves in order to get to you, and this solution won’t work.

If they’re not on the bed, then you will need to maintain a constant supply of fresh kidney bean leaves in order to keep them from the bed. (They can of course approach you in other places you sit or lie down.) You’ll have to remove dried leaves (and impaled bed bugs) regularly and replace them with new.

As such, this may not be an ideal solution, even if it ends up being less expensive and more convenient than bed bug treatment (which I’m not sure will be the case).

17 DancingBug Eaaagh May 11, 2013 at 5:28 pm

After your TyVek bug-stickin’ suit
gets full of stuck bu-ugs just a stickin’ and stuck and stinkin’,
you could send it to the people asking for healthy bugs by mail order!

I can see it now.
(Sorry, I’m being flippant.)

18 nobugsonme May 11, 2013 at 10:45 pm


Once impaled, they might not count as “healthy” anymore.

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