Bedbugs — even reading about them tends to make people itch, and it seems like they are everywhere. While most people are focused on getting rid of them, some researchers are asking how they spread in the first place. Answering this question, says Scientific American's Katherine Harmon, may lead to ways of controlling how they spread. Researchers at North Carolina State University used genetics to trace bedbug lineages, both in the US as a whole and in individual apartment buildings, Harmon says. At the American Society of Tropical Medicine and Hygiene's annual meeting in Philadelphia this week, NC State's Coby Schal said the investigation is forensic in nature.
"Schal and others have analyzed bugs collected up and down the US east coast — and across the country to see whether the vermin have emerged from a few foreign entries, from local animal populations or whether they are repeatedly imported from abroad and then spread throughout the country," Harmon says. "In more finite searches of regional apartment buildings, the researchers also found some dark secrets about bedbug pairing practices that help to explain how they can infest an area so quickly."
The researchers' survey found that the bugs have a lot of genetic variation, suggesting they've come over to the US is several waves, and may be continuing to do so, Harmon adds. But the bugs also show a high rate of inbreeding when it comes to individual apartment buildings. While in most organisms such inbreeding leads to genetic defects that weaken a population, this method of reproduction seems to be perfectly safe for bedbugs, the researchers have found.