"And don't let the bed bugs bite" is no longer a harmless adage. In reality today, these bloodthirsty bugs infest thousands of homes. According to a team of Penn State entomologists, biopesticides -- naturally occurring microorganisms -- might provide an answer 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 in those insects throughout North America and Europe. Compounding the problem are concerns about the safety of using traditional chemicals in the domestic environment.
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. bassianaacts through contact with its insect host.
"They are natural diseases that exist in the environment," said 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," said 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," said 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. bassianais 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," said 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," said Jenkins. "We're working on the next step, and we have more funding to support these studies."
Penn State: http://live.psu.edu
This press release was posted to serve as a topic for discussion. Please comment below. We try our best to only post press releases that are associated with peer reviewed scientific literature. Critical discussions of the research are appreciated. If you need help finding a link to the original article, please contact us on twitter or via e-mail.
Five Disneyland workers have been diagnosed with illness
The first batch of a vaccine against Ebola is on its way to Liberia and trials are expected to start soon.
A drug that protected mice three days after exposure to radiation could buy more time for survivors of a nuclear disaster
Unexpectedly high levels of the cancer-causing chemical were found in an analysis of the vapor from e-cigarettes, researchers say.
When mosquitoes suck blood from people with malaria, they are more likely to develop an infection if their victim is taking antibiotics
Efforts to prevent suicide, such as those championed by Nick Clegg, must take into account some apparently paradoxical differences between men and women
Scientists are studying how hemp might be used in the electronic, medical and manufacturing industries. Because the plant's been illegal for decades, it's been difficult to do research on its uses.
They leave doctors puzzled in their wake as they migrate and settle to feed on the body they're invading; a classic parasite, but this one can get into your head.
The first world war helped spread TB round the world, but it was the collapse of the Soviet Union that enabled the multidrug-resistant form to take off
A recent survey suggests that 71% of people think that the world is going to the dogs. Are things actually that bad, or is it a psychological trick of the mind?