Natural fungus show promise as effective biopesticide for bed bug control
Biopesticides -- naturally occurring microorganisms -- might provide effective bed bug control, a team of Penn State entomologists has suggested.
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.
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. They are relatively easy to produce in a lab and stable, so you can use them much like chemical pesticides," said Jenkins.
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.
This result is important because bed bugs live in hard-to-reach places.
Jenkins' team reported their results in the most recent issue of the Journal of Invertebrate Pathology.