How Did Bed Bugs Come To The United States
They’re Back: A Bed Bug History
These cities are all plagued by a massive resurgence of Cimex lectularius, the speck-sized insect that loves to infiltrate the mattresses–and haunt the dreams–of its human hosts. In the last decade, bed bug calls to exterminators have nearly tripled, according to a survey by the National Pest Management Association and the University of Kentucky. Experts have also noticed that the pests, which are usually associated with residential areas, are venturing into new terrain, cropping up in stores, movie theaters, offices and other public spaces.
This is not the first time America has seen an unwelcome surge in one of its peskiest populations. “Probably, most ships of the 17th century and before harbored bed bugs, and the colonists and their belongings brought them to America,” said Robert Snetsinger, a professor emeritus of entomology at Penn State University. But because the bed bug family comprises many species, he added, we don’t know whether it was Cimex lectularius or one of its many cousins that hitched a ride across the Atlantic. According to Lou Sorkin, an insect expert at the American Museum of Natural History, there is no record of a Native American word for bed bugs, yet another indication of their colonial origins.
On the other hand, ample evidence from other parts of the world suggests that humans have been battling the critters for millennia. In the 1990s, archaeologists found fossilized bed bugs while excavating a 3,550-year-old site in Egypt. They appear in several plays by the ancient Greek writer Aristophanes, who died in 386 B.C., and in the Jewish Talmud, among countless other literary sources. Though generally considered as much of a nuisance in ancient times as today, they were sometimes prized for their supposed medicinal properties: The Roman philosopher Pliny wrote in 77 A.D. that bed bugs could heal snakebites, ear infections and other ailments.
Ever the opportunists, bed bugs thrived in the New World, particularly after the advent of the railroad. In the days before cars and airplanes, many salesmen and other business travelers would stay in rundown hotels near train stations that essentially became “distribution centers for the spread of bed bugs to homes,” said Snetsinger.
As the bed bug population proliferated, so did methods for eradicating the bloodsucking creatures. Early techniques included smoking them out with peat fires, sterilizing furniture with boiling water and scattering plant ash. In the1920s, cyanide fumigation for bed bug management resulted in numerous human deaths, according to Snetsinger, author of “The Ratcatcher’s Child: The History of the Pest Control Industry.” And then, in the 1940s, along came DDT, a pesticide used to kill typhus and malaria carriers during World War II, which proved so effective against bed bugs that their numbers dwindled for almost 30 years.
That golden era for America’s mattresses came to a halt, however, when the Environmental Protection Agency outlawed the chemical for its health and environmental effects. Other insecticides that had helped quell the bed bug epidemic, including chlordane and diazinon, were banned for similar reasons in the 1980s.
Since then, the bed bug population has made a worldwide comeback, nourished in part by a marked increase in international travel. But New Yorkers, Philadelphians and all those who obsessively inspect the seams of their pillowcases can take solace in one important fact: Unlike many of the pests that have run rampant throughout history—from the rats that unleashed the Black Plague on 14th-century Europe to the mosquitoes that continue to infect millions with malaria each year—bed bugs are more annoying than hazardous.
“There have been no studies that positively demonstrate that our common bed bug, Cimex lectularius, transmits disease to people,” said Sorkin. “There have been various disease organisms isolated from bed bugs, but these organisms are not viable and have not been transferred between hosts by the bed bug.”
Return of the bed bug
Evolution and luck have been aiding this bloodsucking parasite’s global spread
Bed bug resting on the fur of one of its animal hosts — a bat.
Gilles San Martin /Flickr (CC BY-SA 2.0)
May 15, 2015 at 6:15 am
If you haven’t met a bed bug, count yourself lucky. These bloodsucking insects have been staging a dramatic comeback in recent years. They can be found in hotel rooms, airplanes, clothing stores and, occasionally, movie theaters. Accidentally bring one or more of these lentil-sized bugs home and your family could have trouble evicting them.
The wingless bugs are reddish-brown, oval-shaped and have six legs. Some people think bed bugs smell musty. Others compare their scent to rotting fruit or pencil shavings.
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Bed bugs live on blood. They usually eat every few days or week, but they don’t need to eat that often to survive. The tiny bugs can go months without a meal. After such an unwanted fast, or even any time they haven’t recently fed, their bodies will be flat. And that helps them hide in little cracks near a bed. But once a bed bug has gorged on a meal — usually human blood, and usually while you are asleep — it plumps up like a miniature balloon. Then it returns to hiding in wait of its next meal.
Cluster of bed-bug bite marks. Magalle L’Abbé/ Flickr (CC BY-NC 2.0) In the past 15 years or so, the bed bug, orCimex lectularius(SY-meks LEK-choo-LAR-ee-uhs), has become common all over the United States, Australia, Europe and parts of Asia. Its comeback has surprised many people because until recently, the pest had been rare for some 60 years in these parts of the world. During that time, some people didn’t even know the bed bug existed. They thought it was a made-up creature from the nursery rhyme:Good night, sleep tight, don’t let the bed bugs bite.
But despite its modern infamy, this pest has been around for a long, long time — hundreds of thousands of years. The earliest bed bugs probably lived in caves, feeding on bats. Those caves may have been in the Middle East, but no one knows for sure. When early humans or their relatives started spending time in such caves, the bugs may have started biting them instead of the bats.
Today, some bed bugs still live with bats in caves, churches and attics in Eastern Europe, says Ondřej Balvín. As an entomologist, he studies insects. In 2012, Balvín and his colleagues at Charles University in Prague, Czech Republic, studied DNA from bed bugs. They compared DNA from the bugs that still feed on bats to the DNA of bed bugs that feed on people. This helped show how long ago bed bugs switched to dining on us.
Scientists know how often DNA typically changes over time, ormutates.The scientists then applied that knowledge to the changes they saw in the DNA of bed bugs slurping human blood versus bat blood. These data suggested bed bugs began living with — and feeding on — our early relatives some 245,000 years ago. More research must be done to confirm that number. But if it’s right, it means the bed bug may predate modern humans.
Out of the caves
However long ago that was, the pest followed our ancestors as they moved out of caves. Bed bugs also are good at hitchhiking. Today, for example, they can hide away in suitcases or bags to move from one home to another. Back in the caves, the same thing likely happened. Only then, the bugs probably latched onto our ancestor’s furs or whatever else they wore or carried.
Hungry bug scouting the best place to dine. ugg/ Univ. of Georgia/ Flickr (CC BY-NC 2.0) As people started living in villages, towns and cities, bed bugs did too. When people invented boats and other ways to travel, some bed bugs would have stowed away in them. Before long, these immigrant insects were a part of human communities the world over. Eventually, bed bugs migrated to America on the same boats that brought human settlers.
The parasites were a common pest in the United States and elsewhere until the late 1940s. That is not long after people started using a powerful new insect killer: DDT.
This bug killer could rid people of all sorts of unwanted pests, including flies and mosquitoes. Americans and people elsewhere sprayed DDT all over their homes. There was even wallpaper that had DDT inside it. The poison probably didn’t wipe out all of the bed bugs. But it did kill enough of them to make the bugs rare.
Until, that is, they found a way to bounce back.
The big comeback
Today, exterminators in all 50 U.S. states are treating bed bug infestations. Spotting new outbreaks also has been increasing rapidly. In the early 2000s, one survey found that only 25 percent of exterminators had been called out to treat bed bugs. By 2011, 99 percent had done so. A similar trend has played out across the globe. One study, for instance, found that by 2006, Australians were battling 46 times as many bed bug infestations as they had just six years earlier.
4 reasons not to ignore signs of bed bugs
How did bed bugs become so common after almost disappearing? Experts think there may be many reasons working together.
“I really do think it was arrogance on our part to think that we had stopped a biological system,” says Dini Miller. “Really, I’m kind of surprised we didn’t have this resurgence earlier.” Miller is a bed bug expert at Virginia Polytechnic Institute and State University. Best known as Virginia Tech, its located in Blacksburg.
One big part of the bed bug picture is the ability of these pests to adapt to their environment. This is known as evolution.
Bed headboard treated with diatomaceous earth to control a bed bug infestation. New York State IPM Prog. at Cornell Univ./ Flickr (CC BY-NC 2.0)
An organism’s genes are always developing random changes, calledmutations. If one of those chance mutations makes a bed bug better able to survive DDT, that bug will live. When it reproduces, its offspring also may carry this now-beneficial gene.
Over time, DDT killed off the sensitive bugs. This left behind more and more of the bugs with that new genetic tolerance to the poison. Eventually, DDT had little or no effect on most bed bugs in heavily treated communities.
Americans stopped using DDT in the 1970s. That’s when evidence began to show the chemical was hurting birds and other valued wildlife. But in some other countries, DDT is still allowed for some uses (such as fighting the mosquitoes that carry malaria). Scientists think that pockets of DDT-resistant bed bugs survived in these countries even when the bugs no longer were common in the United States.
Bed bugs: The ultimate carry-ons
There’s another reason bed bugs have been emerging as a growing problem. They’ve been on the move. Big time.
Starting in the 1980s, people started traveling by airplane more often because new rules made it cheaper and easier to fly. As the price of tickets dropped, more people could afford to travel long distances. It also became easier to fly even between very remote countries.
Experts now think that as people throughout the world started moving more, they began carrying DDT-resistant bed bugs with them. No one is sure exactly where, however, those resistant bugs came from.
Warren Booth is an entomologist at the University of Tulsa in Oklahoma. He is among researchers who think the bugs likely came from one region of the world (although they don’t yet know where). Other scientists aren’t so sure. For instance, Michael Potter of the University of Kentucky in Lexington, thinks resistant bugs may have migrated from many regions at once.
Another advantage for the bugs: More people live in cities than ever before. Because city dwellers tend to live close together — such as in apartment buildings — bed bugs don’t have to move far to find new hosts.
Other features of modern life also may have played a role in the bed bugs’ spread. People who travel spend time in a lot of environments that are friendly to bed bugs. In minutes, a planeload of people from one city will unload and a new group will take their seats. Hours after one hotel guest checks out, a new guest may check into the same room. And then there are all of those people who buy used furniture or rescue it from some discard pile on the street.
Through all of these ways, people have been making it easier for the bed bugs to find new hosts on which to dine.
As these pests have spread, they’ve also proven harder to kill. One big reason is that few insecticides that are effective at killing bed bugs also are considered safe enough to use in our bedrooms.
Pyrethroids (Py-REETH-roids) are one class of chemicals that can be used there. Unfortunately, they kill bed bugs in a way very similar to how DDT works. So all of the bed bugs that can stand up to DDT also tend to be immune to the effects of pyrethroids.
Scientists feed bed bugs (on purpose)
Like Potter, Subba Palli is an entomologist at the University of Kentucky. In 2012, he and a team of scientists found that some bed bugs also have special versions of molecules called enzymes that help them break down insecticides. That tends to make the chemicals less deadly. His team reported its findings inPLOS ONE.
The next year, in 2013, researchers at Virginia Tech found evidence that some bed bugs may be evolving thicker shells, known as exoskeletons. This could make it harder for the poisons to get in and do their damage. Dini Miller, Reina Koganemaru and their team reported the finding inPesticide Biochemistry and Physiology.
“It’s pretty fascinating to think about how these have all evolved,” says Booth at Tulsa. While it’s proven good for the bugs, “it’s not good for those that have infestations in their homes.”
Since entomologists figured out how to raise bed bugs in the lab, they have begun learning all kinds of information about the insects’ behavior. They also are probing new ways to control the bugs. That’s the good news. The not-so-good news: It will take a lot more work before that research turns up new and improved bed-bug killers that are ready for prime time.
For example, scientists have long known that bed bugs, like many insects, talk to each other through chemicals called pheromones. One type — aggregation pheromones — help bed bugs find their way back to their hiding places after they bite you. These chemicals show up in bed bug poop. These signaling chemicals attach to sensors in the bed bugs’ antennae. As the insects get closer to their hiding place, the pheromones get stronger and stronger.
A mix of bed bug eggs and fecal droppings (dark blotches). Harold Harlan/AFPMB/ Flickr (CC BY-NC-ND 2.0) Last year, Joelle Olson and a team of other entomologists from the University of Minnesota in St. Paul cut the antennae off of bed bugs. They wanted to see if it changed the bugs’ ability to sense those homing signals. But cutting the tips off didn’t seem to matter much. When the scientists instead removed the pedicel — a part of these antennae closer to the head — the bed bugs now got lost. They couldn’t find their way home.
The researchers looked at a bed bug pedicel under a powerful microscope and found it had tiny smooth structures with little holes. These may be olfactory organs, the bed-bug equivalent of our nose.
In the lab, researchers have identified some of the chemicals that make up the pheromones that bed bugs find so alluring. They are now trying to develop traps that use these pheromones to coax the pests to their death. Gerhard Gries heads one team in Canada working on this at Simon Fraser University in Burnaby, British Columbia. Last December, his team published a paper inAngewandte Chemiedescribing six of the chemicals that make up the aggregation pheromones.Five of the chemicals attract the bugs to their hideouts. The sixth makes the bugs want to stay there (at least until they get hungry again). A bed-bug trap employing these baits might cost only pennies, the scientists say.
Eek! What if you get bed bugs?
Still, such bug traps won’t clear an infestation — unless the pests actually climb into them. And not all bugs will enter a trap, even one perfumed with pheromones. Some bugs might instead prefer the smell of their original homes. Because of this, scientists also are probing new ways to kill bed bugs without using pyrethroids and other commercial chemicals.
Today, it costs up to $256 million to create each new pest-killing chemical, according to CropLife America. It’s a group that represents companies that make pesticides. It also takes almost 10 years of research testing to bring each new bug killer to market.
That’s why researchers at Pennsylvania State University in State College are excited about a fungus calledBeauveria bassiana(Bo-VAIR-ee-ah BASS-ee-AH-nuh). It occurs naturally in soils all over the world. It also kills insects. The fungus’ dusty white reproductive cells, called spores, stick to the outside of an insect. As the spores grow, they enter the insect’s body. Eventually, the spores bloom and clog the bug’s internal organs, killing it.
A dead bed bug infested with the fungus Beauveria bassiana. The spores of this fungus are under investigation as a possible pest-control treatment. Penn State Univ. In 2012, Penn State entomologists tested the fungus on different types of bed bugs. Within three to six days, each insect was dead.
But even with all this exciting new research, the pest isn’t likely to disappear entirely, notes Stephen Doggett. He’s a medical entomologist at Westmead Hospital in Sydney, Australia. It takes a long time for scientific research to get tested and retested. Only after that can it be turned into a product that you can buy in the store. Another problem: Bed bugs are really hard to kill with any single method. Use just one and a species is likely to develop mutations that make it immune. That’s why exterminators usually have to use many different approaches at once.
Concludes Doggett: “Unfortunately bed bugs are going to be around with us for a long time, as no magical control solutions are on the near horizon.”
Brooke Borel is the author ofInfested, a new book on bed bugs.
(for more about Power Words, clickhere)
antenna(plural: antennae) A pair of long and then sensory organs located on the head of arthropods, including bed bugs and other insects.
bed bugA parasitic insect that feeds exclusively on blood. The common bed bug,Cimex lectularius, sucks human blood and is mainly active at night. The insect’s bite can cause skin rashes and welts that sometimes look like a mosquito bite, but different people react in different ways.
bloom(in microbiology) The rapid and largely uncontrolled growth of a species, such as algae in waterways enriched with nutrients.
DDT(short for dichlorodiphenyltrichloroethane) This toxic chemical was for a time widely used as an insect-killing agent. It proved so effective that Swiss chemist Paul Müller received the 1948 Nobel Prize (for physiology or medicine) just eight years after establishing the chemical’s incredible effectiveness in killing bugs. But many developed countries, including the United States, eventually banned its use for its poisoning of non-targeted wildlife, such as birds.
DNA(short for deoxyribonucleic acid) A long, double-stranded and spiral-shaped molecule inside most living cells that carries genetic instructions. In all living things, from plants and animals to microbes, these instructions tell cells which molecules to make.
entomologyThe scientific study of insects. One who does this is anentomologist.
enzymesMolecules made by living things to speed up chemical reactions.
evolutionA process by which species undergo changes over time, usually through genetic variation and natural selection. These changes usually result in a new type of organism better suited for its environment than the earlier type. The newer type is not necessarily more “advanced,” just better adapted to the conditions in which it developed.
exoskeletonAn external system that supports the bodies of certain animals, including insects, crustaceans, and mollusks. In insects, the exoskeleton is made of a hard material called chitin.
gene(adj. genetic)A segment of DNA that codes, or holds instructions, for producing a protein. Offspring inherit genes from their parents. Genes influence how an organism looks and behaves.
genomeThe complete set of genes or genetic material in a cell or an organism. The study of this genetic inheritance housed within cells is known asgenomics.
infestTo create a parasitic community, such as when wasps infest the porch of an abandoned house. Such a community of pests is known as an infestation.
insectA type of arthropod that as an adult will have six segmented legs and three body parts: a head, thorax and abdomen. There are hundreds of thousands of insects, which include bees, beetles, flies and moths.
insecticideA poison applied to kill insects.
olfaction(adj. olfactory) The sense of smell.
organ(in biology) Various parts of an organism that perform one or more particular functions. For instance, an ovary is an organ that makes eggs, the brain is an organ that interprets nerve signals and a plant’s roots are organs that take in nutrients and moisture.
pedicelA slender stalk or stalk-like part. It normally occurs at the base of something, such as a flower, where it will be attaching to the stem.
pheromoneA molecule or specific mix of molecules that makes other members of the same species change their behavior or development.Pheromones drift through the air and send messages to other animals, saying such things as “danger” or “I’m looking for a mate.”
pyrethroidsA modern family of chemicals that are used to kill insects. It is a human-made version of a naturally insecticide that is made from crush chrysanthemum flowers.
speciesA group of similar organisms capable of producing offspring that can survive and reproduce.
sporeA tiny, typically single-celled body that is formed by certain bacteria in response to bad conditions. Or it can be the single-celled reproductive stage of a fungus (functioning much like a seed) that is released and spread by wind or water. Most are protected against drying out or heat and can remain viable for long periods, until conditions are right for their growth.
How to Find Bed Bugs
If you have a bed bug infestation, it is best to find it early, before the infestation becomes established or spreads. Treating a minor infestation, while an inconvenience, is far less costly and easier than treating the same infestation after it becomes more widespread.
However, low-level infestations are also much more challenging to find and correctly identify. Other insects, such as carpet beetles, can be easily mistaken for bed bugs. If you misidentify a bed bug infestation, it gives the bugs more time to spread to other areas of the house or hitchhike a ride to someone else’s house to start a new infestation. Learn about identifying bed bugs.
Bites on the skin are a poor indicator of a bed bug infestation. Bed bug bites can look like bites from other insects (such as mosquitoes or chiggers), rashes (such as eczema or fungal infections), or even hives. Some people do not react to bed bug bites at all.
Looking for Signs of Bed Bugs
A more accurate way to identify a possible infestation is to look for physical signs of bed bugs. When cleaning, changing bedding, or staying away from home, look for:
- Rusty or reddish stains on bed sheets or mattresses caused by bed bugs being crushed.
- Dark spots (about this size: •), which are bed bug excrement and may bleed on the fabric like a marker would.
- Eggs and eggshells, which are tiny (about 1mm) and pale yellow skins that nymphs shed as they grow larger.
- Live bed bugs.
Where Bed Bugs Hide
When not feeding, bed bugs hide in a variety of places. Around the bed, they can be found near the piping, seams and tags of the mattress and box spring, and in cracks on the bed frame and headboard.
If the room is heavily infested, you may find bed bugs:
- In the seams of chairs and couches, between cushions, in the folds of curtains.
- In drawer joints.
- In electrical receptacles and appliances.
- Under loose wall paper and wall hangings.
- At the junction where the wall and the ceiling meet.
- Even in the head of a screw.
Bed Bugs FAQs
What are bed bugs?
Bed bugs (Cimex lectularius) are small, flat, parasitic insects that feed solely on the blood of people and animals while they sleep. Bed bugs are reddish-brown in color, wingless, range from 1mm to 7mm (roughly the size of Lincoln’s head on a penny), and can live several months without a blood meal.
Where are bed bugs found?
Bed bugs are found across the globe from North and South America, to Africa, Asia and Europe. Although the presence of bed bugs has traditionally been seen as a problem in developing countries, it has recently been spreading rapidly in parts of the United States, Canada, the United Kingdom, and other parts of Europe. Bed bugs have been found in five-star hotels and resorts and their presence is not determined by the cleanliness of the living conditions where they are found.
Bed bug infestations usually occur around or near the areas where people sleep. These areas include apartments, shelters, rooming houses, hotels, cruise ships, buses, trains, and dorm rooms. They hide during the day in places such as seams of mattresses, box springs, bed frames, headboards, dresser tables, inside cracks or crevices, behind wallpaper, or any other clutter or objects around a bed. Bed bugs have been shown to be able to travel over 100 feet in a night but tend to live within 8 feet of where people sleep.
Do bed bugs spread disease?
Bed bugs are not known to spread disease. Bed bugs can be an annoyance because their presence may cause itching and loss of sleep. Sometimes the itching can lead to excessive scratching that can sometimes increase the chance of a secondary skin infection.
What health risks do bed bugs pose?
A bed bug bite affects each person differently. Bite responses can range from an absence of any physical signs of the bite, to a small bite mark, to a serious allergic reaction. Bed bugs are not considered to be dangerous; however, an allergic reaction to several bites may need medical attention.
What are the signs and symptoms of a bed bug infestation?
One of the easiest ways to identify a bed bug infestation is by the tell-tale bite marks on the face, neck, arms, hands, or any other body parts while sleeping. However, these bite marks may take as long as 14 days to develop in some people so it is important to look for other clues when determining if bed bugs have infested an area. These signs include:
- the bed bugs’ exoskeletons after molting,
- bed bugs in the fold of mattresses and sheets,
- rusty–colored blood spots due to their blood-filled fecal material that they excrete on the mattress or nearby furniture, and
- a sweet musty odor.
How do I know if I’ve been bitten by a bed bug?
It is hard to tell if you’ve been bitten by a bed bug unless you find bed bugs or signs of infestation. When bed bugs bite, they inject an anesthetic and an anticoagulant that prevents a person from realizing they are being bitten. Most people do not realize they have been bitten until bite marks appear anywhere from one to several days after the initial bite. The bite marks are similar to that of a mosquito or a flea — a slightly swollen and red area that may itch and be irritating. The bite marks may be random or appear in a straight line. Other symptoms of bed bug bites include insomnia, anxiety, and skin problems that arise from profuse scratching of the bites.
Because bed bug bites affect everyone differently, some people may have no reaction and will not develop bite marks or any other visible signs of being bitten. Other people may be allergic to the bed bugs and can react adversely to the bites. These allergic symptoms can include enlarged bite marks, painful swellings at the bite site, and, on rare occasions, anaphylaxis.
How did I get bed bugs?
Bed bugs are experts at hiding. Their slim flat bodies allow them to fit into the smallest of spaces and stay there for long periods of time, even without a blood meal. Bed bugs are usually transported from place to place as people travel. The bed bugs travel in the seams and folds of luggage, overnight bags, folded clothes, bedding, furniture, and anywhere else where they can hide. Most people do not realize they are transporting stow-away bed bugs as they travel from location to location, infecting areas as they travel.
Who is at risk for getting bed bugs?
Everyone is at risk for getting bed bugs when visiting an infected area. However, anyone who travels frequently and shares living and sleeping quarters where other people have previously slept has a higher risk of being bitten and or spreading a bed bug infestation.
How are bed bugs treated and prevented?
Bed bug bites usually do not pose a serious medical threat. The best way to treat a bite is to avoid scratching the area and apply antiseptic creams or lotions and take an antihistamine. Bed bug infestations are commonly treated by insecticide spraying. If you suspect that you have an infestation, contact your landlord or professional pest control company that is experienced with treating bed bugs. The best way to prevent bed bugs is regular inspection for the signs of an infestation.
This information is not meant to be used for self-diagnosis or as a substitute for consultation with a health care provider. If you have any questions about the parasites described above or think that you may have a parasitic infection, consult a health care provider.
History & Resurgence
Bed bugs were a common problem in the United States up through the World War II era. Around this time, they were virtually eradicated from the US with the wide scale usage of pesticides, such as DDT and Malathion. During the late 1990’s bed bugs began to re-emerge as a pest in the United States, Canada, Australia, the UK, along with a number of other countries. Their secretive behavior, coupled with a lack of public awareness, has enabled this insect to move very efficiently from one dwelling to another and has facilitated their rapid dispersal throughout the country.
While no one can say for certain what caused the resurgence of bed bugs in the United States, there are a number of factors that have probably influenced the re-emergence of this difficult pest. There has been a general increase in bed bug activity on a world-wide basis over the past decade. Due to the increased prevalence of bed bugs world-wide, the frequency of encounters with bed bugs during travel is also likely to have increased resulting in a greater number of introductions into the US than in the past. Most of the early introductions appear to have been associated with travel as many of the early infestations in the late 1990’s were identified in hotel guest rooms.
It is also likely that changes in pest management practices coupled with the development of resistance to modern day pesticides has contributed to the successful re-establishment of bed bug populations in the United States. In the past, hotel guest rooms were typically treated on a regular basis with residual pesticides. As a result, bed bugs introduced during travel were likely to contact pesticide as they left the luggage and traveled to the bed. During the mid 1990’s there was a dramatic shift in pest management practices. Routinely scheduled treatments of baseboards in hotels, motels and apartments were replaced with targeted applications of baits for pests such as ants and cockroaches. With the absence of the residual pesticide applications, bed bugs are able to travel freely and safely from the luggage to the bed, and successfully begin an infestation. It is likely that these factors have played a role in the bed bug’s ability to become re-established in the United States.
Now that bed bugs are back, they are spreading throughout the United States at a very rapid rate. Bed bugs are excellent hitch hikers and once they are introduced into an environment are able to readily spread from infested locations to new locations that were previously un-infested. All one needs to do is to spend a night in a bed bug infested environment and there is a good chance that they will take bugs with them to their next destination. Some of the more common dispersal mechanisms include overnight stays in bed bug infested quarters, the purchase of infested furniture (rental furniture, used/second hand furniture, reconditioned mattresses etc.), the acquisition of discarded items that are infested, and migration of bed bugs from one infested dwelling to another in multi-occupancy settings (apartments, college housing, medical facilities, senior communities etc.)
Perhaps the most significant factor that has enabled bed bugs to spread throughout the US at an exponential rate is the lack of public awareness. Many people simply don’t believe or realize that bed bugs truly exist. As a result people do not think twice before picking up discarded furniture that is infested with bed bugs and bringing them into their home. Once the bugs are introduced it is not uncommon for infestations to go undetected for several months or more. One of the reasons that infestations are not detected sooner has to do with the cryptic and secretive habits exhibited by bed bugs. They are mostly active at night, coming out of secretive hiding places to feed on people as they lay fast asleep. Their bite is painless so people are unaware that they have been bitten. Once they have finished taking a blood meal they retreat back to their hiding places where they remain undetected and are not likely to come back out until it is time to feed again (often going several days to a week or more between blood meals). In addition many people must first become sensitized to the bite before developing any bite symptoms while others never react at all. As a result it is not uncommon for people to have delayed reactions of several weeks or more. Even when symptoms do occur, they are often confused with poison ivy, scabies, allergic reactions etc. All of these factors enable bed bugs to become very well established before the occupants of the infested structure identify the infestation.