By Gwyneth Dickey Zakaib
The battle between humans and bed bugs may have its origins in prehistoric times, but in recent years it has reached a fever pitch thanks to an apparent resurgence of the tiny bloodsuckers in North America, Europe, Australia and East Asia. Now public officials are looking to genetics to turn the tables on an ancient and persistent foe.
Bed bug experts highlighted their progress this week at the second National Bed Bug Summit , held on 1-2 February in Washington, DC. The US government convened the summit, which included participants from various agencies as well as academic and pest-control industry specialists, to discuss progress since the last summit two years ago and propose possible solutions to the bed bug epidemic.
“The idea is to come up with a national agenda … to reduce the burden of bed bugs in communities,” said Colby Schal, an entomologist from North Carolina State University who presented at the meeting. “It’s essentially becoming a global problem.”
Genetics was in the spotlight at the meeting because of its potential to trace the spread of bed bugs, reveal how they develop insecticide resistance and point the way to controlling them in the future. For example, using pieces of the bedbug genome as molecular markers, researchers have determined that bed bugs found along the US East Coast are very diverse, having likely been introduced to the region multiple times from other points around the globe. Yet, within populations, genetic diversity is low, meaning an entire infestation can arise from one pregnant female. Such markers have been used to track how bed bugs spread within a single apartment building.
Genetics can also help figure out how bed bugs thwart human efforts to poison them. A recent paper by researchers at Ohio State University suggests insecticide-resistant bed bugs produce higher levels of a toxin-neutralizing enzyme. Such enzymes could be targets for future pesticides. The same paper shows that almost 45% of bed bug proteins (deduced from mRNA analysis) are unique among insects. Distinctive proteins may be further potential targets for insecticides aimed specifically at bed bugs.
“This is a huge array of genes and gene products that have the potential to be used in pest control,” said Schal, who highlighted the paper in his talk.
Other researchers are exploring chemicals that could be used in bait-and-kill strategies. Things like bed bug pheromones and fragrant human aromas could be used to detect, disperse or attract bed bugs.
While the summit is evidence of continued focus on the bed bug problem, it doesn’t mean researchers are close to a solution. They desperately need more resources to move forward with bed bug studies, Schal says. A complete bed bug genome would be especially helpful to identify more pesticide targets, he says. Right now, pesticides target only a few sites, primarily in the nervous system. He and his colleagues are currently drafting a proposal to NIH to fund the sequence of the full bed bug genome. An online site to consolidate relevant literature would also be useful, Schal adds.
“It’s extremely urgent,” Schal says. “The bed bug situation doesn’t look like it will get better anytime soon and I certainly think it will get much worse in the next few years.”
Photo Credit: Janice Haney Carr