If Your Family Tree is a Straight Line …

Incest is best – or is at least very acceptable – for bedbugs looking to colonize new areas, according to new research from NC State entomologists Coby Schal, Ed Vargo and Warren Booth.

The research, presented today at the American Society of Tropical Medicine and Hygiene annual meeting in Philadelphia and currently undergoing peer review, shows that bedbugs from apartment buildings were more than just kissing cousins. Individual apartments and indeed entire buildings contained closely related bedbugs; this lack of genetic diversity suggests that infestations start from just one or two introductions of the insect.

“Inbreeding gives bed bugs an advantage in being able to colonize,” Schal said. “A single female that has been mated is able to colonize and start a new infestation. Her progeny and brothers and sisters can then mate with each other, exponentially expanding the population. With many organisms, extensive inbreeding would cause serious mutations that would eventually bring about an end to the population.”

The NC State researchers found the same types of inbreeding in more than 20 separate infestations studied from Maine to Florida – in individual infestations inbreeding seemed to be a powerful influence on population gains.

However, when comparing bedbugs from New Jersey with bedbugs from Florida, populations along the East Coast showed high genetic diversity, suggesting that the bedbugs are coming from many different places – nationally and internationally. When humans travel, they unwittingly pick up bedbug “hitchhikers” and carry them to new places; research suggests travel and changing residences are some of the main drivers behind new bedbug infestations.