Bedbugs are not known to transmit disease to or among people, but that doesn’t make them any less scary. About the size of an apple seed, they eat human blood and usually bite a sleeping host at night. Josh Cassidy / KQED Hide caption
Josh Cassidy / KQED
Josh Cassidy / KQED
Summer is a time of travel and fun. But with every bed a weary traveler falls into after a day of sightseeing, the likelihood of bringing an unwanted bug home increases.
Bedbugs won’t fly, jump or come out of your yard. They crawl very quickly and are great hiding in your luggage when you travel and take a ride to your home or hotel room.
“It would probably be wise to do a quick bed check if you sleep in someone else’s bed,” says Michael Potter, an entomologist at the University of Kentucky who studies bed bugs. His recommendation applies to beds in chic hotel rooms, as well as dormitories and bunk beds in summer camps.
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What does Potter do when traveling? First, he holds his suitcase with a zipper and on a sideboard or metal luggage rack. Bedbugs have a hard time climbing on smooth surfaces such as metal.
Next, he recommends pulling back the sheet at the head of the bed and checking the seams at the top and bottom of the mattress and box spring bed. Contrary to popular belief, bedbugs do not dig into mattresses. They stay on the surface. And after they feed on us, they find a hiding place where they leave telltale brown or yellow droplets of digested blood called fecal stains. If they have already had the opportunity to reproduce, their nest could contain translucent egg shells and young yellowish nymphs.
“They’re more of a nest insect,” says Bill Donahue, entomologist and owner of Sierra Research Laboratories in Modesto, California, where he evaluates treatments for bedbugs and other pests. “There are areas where the bugs will congregate.”
Adult bedbugs are about the size and color of an apple seed. Young beetles, called nymphs, are smaller and yellowish or white. Guided by the carbon dioxide and heat emitted by sleeping people, they quickly crawl over wooden bedposts and sheets to stick their long mouth parts in and drink for about five minutes until they are completely full. They then hide in a nearby nook, like the seam of the mattress or behind a baseboard.
“Heaven forbids you to wake up with itchy red welts during your stay,” says Potter. “Then you want to be incredibly vigilant when you get home.”
Bug Nymphs Josh Cassidy / KQED hide caption
Josh Cassidy / KQED
Protect your home
He suggests putting clothes in the dryer or leaving unpacked suitcases in a hot car, as bed bugs are prone to high temperatures. It takes some people days or even weeks to react to a bedbug bite, so bites are not a good indicator of when you’ve been exposed to them. And while some people can have a severe skin reaction, bedbugs are not known to transmit disease.
Bed bugs were common in the United States until the 1940s. After being nearly wiped out by the spraying of DDT in the 1950s, they have made a comeback worldwide in the past 20 years, aided by the widespread movement of people. According to Potter, they have been found across the country in settings as diverse as schools, dormitories, hospitals, theaters, moving trucks and even funeral homes. And they move on used furniture too.
Residents are more prone to infestation as insects can crawl from one apartment to another. Because bedbugs hide, they are difficult to treat without the help of a professional, and treatments can be expensive.
“If you think you have bed bugs, let your landlord know right away,” says entomologist Andrew Sutherland, the University of California’s pest control advisor in the San Francisco Bay Area. “It is your responsibility to conduct inspections and have a reputable pest control operator deal with the problem.”
Treat with heat
Because bed bugs are prone to heat, heat treatment is “the gold standard,” said Luis Agurto, CEO of Pestec, a pest control company in the San Francisco Bay Area. Pestec sets up large heaters in an infested residence and heats them to 122 degrees Fahrenheit for two hours. Technicians armed with “guns” blow hot air into areas where bed bugs may be hiding.
“We basically make a big fan oven,” explains Agurto.
After heat treatment, Pestec monitors bed bugs for several weeks by placing a hard plastic cup under each bed post. The insects have no problem climbing up the rough outside of these so-called catching cups, but they are caught by the smooth inside surface, which they cannot scale. The company also uses insecticides and vacuum cleaners to clean up the infestation.
Scientists are working hard to expand their eradication toolset. At the University of California, Irvine, biologist and engineer Catherine Loudon, works with several technical laboratories on campus to create synthetic surfaces that can better intercept the insects. It was inspired by the tiny hook hairs that grow from the leaves of some types of beans, such as kidneys and green beans. In nature, these spiky hairs, called trichomes, pierce the feet of aphids and cicadas, which love to feed on them.
Balkan folk wisdom seed science
Loudon got the idea from Potter at the University of Kentucky, who mentioned a folk remedy he had read about. Balkan residents were throwing bean leaves around their beds, Potter said, and in the morning they would find bedbugs on the leaves. It turned out that the beetles’ feet were impaled by the hook hair. Researchers have found that trichomes are just as effective against bed bugs, despite not feeding on leaves.
Loudon’s goal is to mimic the mechanism of a bean leaf to create an inexpensive, portable trap.
“You can think of a strip that acts as a barrier and can be placed practically anywhere: across the portal to a room, behind the headboard, on subway seats, on an airplane,” says Loudon. “You have six legs, so there are six ways to get caught.”
This post and video were produced by Deep Look, a wildlife video series by KQED and PBS Digital Studios that explores “the invisible at the very edge of our visible world.”
Gabriela Quirós from KQED is the coordinating producer of the series. Laura Shields from KQED contributed to the coverage.