- Associated Press - Wednesday, December 7, 2011

PITTSBURGH (AP) - Bedbugs aren’t just sleeping with you. They’re sleeping with each other.

Researchers now say that the creepy bugs have a special genetic gift: withstanding incest.

It turns out that unlike most creatures, bedbugs are able to inbreed with close relatives and still produce generally healthy offspring. That means that if just a few bedbugs survive in a building after treatment, they repopulate quickly.

Coby Schal and Ed Vargo are entomologists at North Carolina State University, and they presented preliminary research on genetic diversity in bedbug populations on Tuesday in Philadelphia, at the annual meeting of the American Society of Tropical Medicine and Hygiene.

“We kept discovering the same thing. Within a given apartment, or even a given building, there was extremely low genetic diversity,” said Schal. “In most cases there’s just a single female that founded the population.”

Schal said that was a surprise, since an animal or insect population with limited diversity will usually build up and then crash, because genetic defects tend to magnify with inbreeding.

“But somehow bedbugs are able to able to withstand the effects of inbreeding, and do quite well,” he said.

The new research is important, said Zachary Adelman, an entomologist at Virginia Tech University who wasn’t part of the North Carolina State team.

“No one had looked at these things,” he said of the genetic makeup of bedbugs. “It’s pretty exciting.”

And pretty depressing.

The researchers also found that while the community within a building tends to be similar, there are many different strains of bedbugs throughout the East Coast, suggesting that new colonies also get introduced through foreign travel or commerce.

“That means they’re coming into the country from lots of different places,” which means that the bedbug problem isn’t going to stop anytime soon, said Adelman.

The findings may also help explain another part of the bedbug boom.

Bedbugs _ and other insects _ develop resistance to insecticides. Schal said that if a treatment kills anything less than 100 percent of the bugs, the survivors will not only repopulate, but pass on the resistance they’ve developed to future generations.

“The insecticides really need to be robust” to do the job, Schal said.

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