There was a time when parents putting children to bed would tell them to "sleep tight and don't let the bedbugs bite." While that little rhyme was simply a cute phrase to kids growing up in the middle of the last century, these days it could well be taken as a serious warning. According to one 2011 survey, one in five Americans has either had a bedbug infestation in their home or knows someone who's come in contact with the critters in a hotel room or their homes, and every continent except Antarctica has experienced a resurgence during the past two decades. Combine that with the fact that bedbugs are becoming more and more resistant to insecticides meant to destroy them, and you can see how serious the issue is becoming.
Fortunately scientists have just taken a key step in stopping the bitty blood suckers in their tracks – they've decoded the entire bedbug genome.
Researchers at the American Museum of Natural History and Weill Cornell Medicine took DNA and RNA from both living and preserved bedbugs. They retrieved samples from a bedbug population first collected in 1973 (and since maintained by the museum), as well as from more than 1,400 locations in New York City, including every subway station.
What they found was that gene expression changes after a bedbug has its first blood meal. Some of the genetic mutations the bedbugs undergo allows them to develop resistance to insecticides by creating a better internal detoxification system or by forming a thicker skin.
Knowing this, attacking the bugs during their nymph stage, before they first drink blood, could be smart strategy for stopping them in their bloody little tracks.
The researchers also studied the genetic makeup of the bedbug's microbiome –basically, the bugs that live on the bugs. They found genes related to over 400 types of bacteria, some of which help the bedbugs reproduce and grow. Developing antibiotics that destroy these helpful bedbug bacteria could also be another way to squash the spread of the critters.
The work of the researchers, which was published in Nature Communications on February 2, comes on the heels of another study published last month, which stated that bedbugs have become more than 30,000 times more resistant to certain insecticides over the years. So seeking out the means to destroy them with novel methods is now more critical than ever.
The data obtained from different locations can also be used to improve our understanding of how bedbug infestations spread throughout cities.
"Bedbugs all but vanished from human lives in the 1940s because of the widespread use of DDT, but unfortunately, overuse contributed to resistance issues quite soon after that in bedbugs and other insect pests," said Louis Sorkin, an author on the paper and a senior scientific assistant in the museum's Division of Invertebrate Zoology. "Today, a very high percentage of bedbugs have genetic mutations that make them resistant to the insecticides that were commonly used to battle these urban pests. This makes the control of bedbugs extremely labor-intensive."
Hopefully, now that we know what makes the bedbugs tick, we can find out ways to short-circuit their biological clocks or at least strip them of the bacteria that helps them thrive. Till then … don't let the bedbugs bite.