Spray-on fungus could kill bed bugs

PENN STATE (US) — Rather than harsh chemicals, the answer to a bed bug infestation may be a fungus, say entomologists.

“And don’t let the bed bugs bite” isn’t just a harmless adagethese bloodthirsty bugs infest thousands of homes. According to a team of Penn State entomologists, biopesticides –naturally occurring microorganisms—might provide a solution to this pest problem.

Bed bugs need blood meals for growth and development throughout their life cycle. Increased travel, widespread insecticide resistance, and changes in management practices have caused a resurgence of the insects throughout North America and Europe. Compounding the problem are concerns about the safety of using traditional chemicals in the domestic environment.

A bed bug with Beauveria bassiana sporulating on its cadaver. (Credit: Penn State/Flickr)

According to Nina Jenkins, senior research associate in entomology, preliminary bioassays on the effects of Beauveria bassiana—a natural fungus that causes disease in insects—on bed bug control have been performed, and the results are encouraging. She and her colleagues report their results in the most recent issue of the Journal of Invertebrate Pathology.

Jenkins, working with Alexis Barbarin, a former Penn State postgraduate student now at the University of Pennsylvania, Edwin Rajotte, professor of entomology, and Matthew Thomas, professor of entomology, looked at how B. bassiana acts through contact with its insect host.

“They are natural diseases that exist in the environment,” says Jenkins. “They are relatively easy to produce in a lab and stable, so you can use them much like chemical pesticides.”

In the study, the researchers used an airbrush sprayer to apply spore formulations to paper and cotton jersey, a common bed sheet material. Then control surfaces, again paper and cotton jersey, were sprayed with blank oil only. The surfaces were allowed to dry at room temperature overnight.

Three groups of 10 bed bugs were then exposed to one of the two surfaces for one hour. Afterward, they were placed on clean filter paper in a petri dish and monitored.

The researchers found that all of the bed bugs exposed to the biopesticide became infected and died within five days.

Also, there were no prominent differences in susceptibility by feeding status, sex, strain, or life stage. Most importantly, the infected bed bugs carried the biopesticide back to their hiding places, infecting those that did not go out in search of blood.

“We exposed half of a population of bed bugs to a spray residue for one hour and then allowed them to go into a harborage with unexposed individuals,” says Jenkins. “The fungal spores were transferred from the exposed bug to their unexposed companions, and we observed almost a hundred percent infection. So they don’t even need to be directly exposed, and that’s something chemicals cannot do.”

This result is important because bed bugs live in hard-to-reach places.

“Bed bugs tend to be cryptic, and they’ll hide in the tiniest crevices,” says Jenkins. “They don’t just live in your bed. They hide behind light switches and power sockets and in between the cracks of the baseboard and underneath your carpet.”

The speed of mortality with B. bassiana is as fast as Jenkins has seen in any application, but it doesn’t even need to be that fast.

“If you are trying to protect a farmer’s field, he wants the insects that are eating his crop dead immediately,” says Jenkins. “Obviously, if you have bed bugs in your house, you don’t want them there for any longer than you have to, but what you really want to know is if they’ve all gone at the end of the treatment, and I think that’s something that this technology could offer.”

Next, the researchers will test the effectiveness of brief exposure times and look at entire populations where natural harborages are established. Then they will begin field work.

“It’s exciting, and it definitely works,” says Jenkins. “We’re working on the next step, and we have more funding to support these studies.”

Source: Penn State

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  1. michele

    before using ton of insecticide in your home think that bedbugs are NOT connected to any disease. Yes, they eat your blood but a drop can feed hundreds, if not thousand, of them and you can lose one or two drops at all!!This fungus is safe for us? We don’t really know!Bedbugs can adapt to this fungus? Sure!

  2. lowkey

    OK, we now no that Beauveria bassiana is the answer, and that’s good. Where do you sell it, how do you use it? Is it on the market?

  3. Richard

    Was doing some research on this myself. It looks as if there are no commercial products targeted towards bed bugs. Almost all the products i have seen are for Agricultral purposes. There are sprays and powers. I’m sure these would work but have no clue if they would cause other problems because they may have other ingredients for other purposes. Been dealing with this problem for a while. These things are hard to get rid of. Hoping someone will come out with a product using this soon. Oh and for the poster above, they may not cause any real harm, when a child wakes up with bumps all over them what are you going to tell them. You really can’t tell them there are little bugs crawling over them at night biting them. So here’s hoping for a product soon.

  4. James Norris

    I hate bed bug problems and I didn’t even know a bed bug spray existed. I think it would be awesome to get a hold of that. I need it.

  5. kimbee

    michele – you must be one of the lucky people that doesn’t have a reaction to bed bug bites! I got bitten on holiday all down one side of my body and man were those bites itchy! It was worse than the chicken pox when I was a kid. No way that I could live with them.

  6. Len

    Chlorine Dioxide can also kill bed bugs and is currently being studied and developed for that purpose, among others. It leaves no harmful residue but the room/home/space must be vacant durring treatment. It needs to be applied as both a liquid form and gaseous form overnight to be truely effective.

  7. David Z

    Len, I’ve actually had experiences with Chlorine Dioxide. The problem is I’ve heard mixed results. Hopefully someone out there can get THE Definitive solution!

  8. Palm Coast Pest Control

    Interesting Post. hopefully soon it can be implemented at max throughout the pest control world. David as far as I know there have not been mixed results

  9. Vett Vett

    Just use Bounce Dryer sheets. gets them out your house and life. Who knew? Bed bugs are hideous. My son and I were going crazy from being eaten. Bites were all over our bodies, until a friend told me about bounce dryer sheets. Put them all over the house. I mean all over. Including your car, purse, and pockets when you leave home. Watch it work.

    Got the 411 on bed bugs

  10. pest control Bromley

    You are doing the very nice job guys by your efforts people will get much knowledge on the latest things well.

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