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The Frontlines Of The War On Bedbugs

Rick Santangelo and Virna Saenz, researchers from NC State, search for bedbugs in an infested mattress. Photo: Rose Hoban

Bedbugs are back and they're popping up everywhere. Major cities in the US and Europe are reporting new infestations. Exterminators and scientists are scrambling to control them. Scientists from North Carolina State University are part of that fight. Rose Hoban of North Carolina Public Radio reports from the front lines of the bedbug wars. A few years ago, Stephen Rider noticed he was getting red, raised, itchy bug bites on his arms. At the beginning, it just seemed like a mosquito bite, or two. And then," he says, "they don't go away and then you start having more and more. At first I thought it was chiggers or sand ants or something." After a few weeks, Rider figured it out. He'd moved into a furnished apartment in a student housing complex in Chapel Hill a few weeks before. Either a previous tenant or a neighbor had brought the critters in. They made their home in Rider's apartment - and his mattress, where they have easy, daily access to a human they can feed on. "It's kind of icky," he admits. "But on the other hand, the only time that they bite is when you're sleeping, and they're actually very good at making it so that you don't feel it, and they are not a disease vector. That being said, I did sleep on an air mattress in the living room." After washing all his clothes and wrapping his mattress in an impermeable bag, Rider moved to an apartment complex down the street. He hasn't had a problem since. But plenty of other people in North Carolina have, as bedbugs make a resurgence. The pest control company, Orkin, says calls for bedbug infestations in the Triangle jumped 35 percent in each of the last two years. Bug Collection Rick Santangelo, an urban entomologist from North Carolina State, is collecting bedbug samples in a Raleigh apartment building. Santangelo says some folks in the building had bedbugs, and had gotten treatment. "We are now going back to adjacent apartments to check the adjacent apartments to find out if they've also got infestations. If they do, we can do genetic analysis to determine whether it's the same population are different population." Accompanying Santangelo was doctoral student Virna Saenz. She's analyzing the genetic of bedbugs. The pair proceed to take apart the bed of a man who declined to have his name used. In the seams of the mattress, there they are. Some of the small brown bugs are obviously engorged with blood, as well as some of the immature bedbugs, called instars. It only takes 30 days for the instars to go through the nymph stage to full grown adult. In the next apartment we visit, we get on our hands and knees to chase them under an infested couch. "A lot of eggs, babies, and all sizes," Saenz says. A baby, or instar, is biting her hand. "They take a blood meal. And they don't molt until they feed on blood, so they need blood to grow." Saenz collects several vials of live bedbugs to take back to the lab at NC State. There, the plan is to grind them up and compare their DNA. If all the DNA in the bugs from this building is the same, it means the infestation probably spread outward from one focal point in the building. If the DNA is different, then the bedbugs were probably introduced at different times by different carriers. " We want to do a genetic map of all bedbug populations, how they spread from city to city," Saenz says. There's other information to be gleaned from the bedbug DNA, like how the critters are becoming resistant to many pesticides. Pesticides used now against bedbugs are less toxic than older chemicals, such as DDT. But they're also less potent. " There's strong selective pressure," Santangelo says. "So, if you're killing off all of the susceptible individuals you're left with those that have the genetics to resist the pesticide. Those breed and produce more that are resistant and the cycle continues, so you are increasing resistance the more pesticides you use." Santangelo says that's why it's not a good idea to be a do-it-yourselfer when it comes to eliminating bedbugs, lest you leave the hardy ones behind to reproduce. He says there's really no good one-size-fits-all treatment to get rid of bedbugs. And that means, more people will probably get familiar with them in coming years.