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Bedbug Revival 2011: What You Need to Know

The views expressed are those of the author and are not necessarily those of Scientific American.

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Bedbug sprays sold for residential use in neighborhood stores rarely eradicate or prevent bedbugs. Credit: Amy Maxmen

In April I moved from one bedbug infested district of Brooklyn to one infested worse. With 550 complaints filed in the bedbug registry in 2008, Bushwick, my new neighborhood, surpassed Central Harlem in Manhattan, Astoria in Queens, and University Heights in the Bronx. At every hardware and grocery store on the surrounding blocks, I eyed the array of bedbug sprays for sale beside the cash register. And had I not talked to experts while writing this blog post, I would have bought them as a preventative measure.

Among other misguided beliefs, the myth of bedbug spray seems to worry scientists and public health authorities the most. So I’ll start there.

DIY pesticides don’t work.

During the last 50 years, bedbugs have largely become biologically resistant to the pesticides sold at your corner store, namely pyrethroids and pyrethrins. DDT targets the same site as pyrethroids do, shedding doubts on claims that lifting the EPA’s ban on this dangerous chemical would curb the current bedbug resurgence. Spraying pyrethroids or pyrethrins directly on a resistant bedbug at close range may in fact kill the pest, but there’s little chance of hitting each individual insect, as armies of the sesame-seed sized bugs hide in the teeniest crevices.

"Hair spray, Windex, spearmint or eucalyptus oil will kill bedbugs at a close range too," says Coby Schal, an urban entomologist at North Carolina State University in Raleigh. "But I’m not advocating those approaches because bedbugs can walk right over these sprays." Although the insect repellent DEET is not a pyrethroid or pyrethrin, Schal says it won’t deter a starving bed bug from seeking out human blood. Instead, repellants and sprays encourage the bugs to explore unsprayed territory, like your living room or your neighbor’s flat.

Young and adult bedbugs fat after a blood meal. The brown spots are fecal smears of digested blood. Credit: Benoit Guenard

Pesticide resistance provides tremendous evidence for evolution by natural selection. A mutation in a gene encoding a protein in bedbugs’ nerve cells allows the cells to resist the lethal damage inflicted by pyrethroid and pyrethrins. With each spray, bedbugs with the mutation out-live their non-resistant pals and survive to produce resistant offspring. Incidentally, cockroaches have mutations in this protein, too. If it weren’t for poisoned bait, we might have a hefty cockroach problem on our hands, says Schal. At the moment, he is studying what attracts bedbugs to human blood. If this compound can be identified and mimicked, bedbugs might be baited, too.

Nonetheless, pyrethroid and pyrethrin sprays sell fast. And so do "bug bombs," cans of pesticide (typically pyrethroids) that release their contents at once. (One report describes a man blowing out the walls of his apartment by setting off the bug bomb near a gas stove with the pilot lights on—aerosol ignites.) These bombs fall in vain. Even if pyrethroids still worked, the bombs rarely send pesticide into cracks and voids where bedbugs dwell (1).

Worse yet, misuse of these sprays may lead to digestive problems, skin irritation, and may worsen asthma and allergies (1). "People think if you can buy a pesticide at a supermarket it can’t be dangerous, so they use them like mad when in fact almost none of these chemicals have been tested on humans," says Stephanie Chalupka, an environmental and occupational health expert in Massachusetts at Worcester State College and Harvard School of Public Health in Boston. "I think the public health community could do a better job of getting out information on what is useful and safe, and what may put kids at risk." Chalupka says she’s particularly concerned for pregnant women and their developing babies. "All sorts of compounds can get to the developing fetus, which is at a very vulnerable state as its organs and systems are forming."

Not all bugs are bedbugs.

Timothy Wong of M&M Pest Control in New York says 70 percent of the time, residents who call his company turn out to be bedbug-free. Mosquitoes, spiders and fleas leave itchy bites, too, and various other insects occupy our dwellings. Common bedbugs (Cimex lectularius) are reddish-brown and range from the size of a poppy seed to the size of a short grain of rice, depending on their age. Clumps of 10 to 50 white eggs, about the size of a pinhead, may be found in the vicinity of the bugs.

Bedbugs living on a mattress. Credit: Jung Kim and Rick Santangelo

To find bedbugs, check creases and seems in your mattress and box spring, behind the headboard, between couch cushions, under rugs, in nightstand drawers, under loose wallpaper, and cracks in plaster. Sometimes bedbugs leave behind bloodstains—pinprick-size droplets not to be confused with the rectangular feces left by cockroaches.

Clean or messy, bedbugs don’t discriminate.

"We’ve had calls from residents in filthy places and calls from residents who live on Park Avenue with full-time housekeepers," says Janet Friedman of Bed Bug Busters NY (a company of actors, singers and stage managers who prep apartments for exterminators on the side). Don’t be fooled by clean hotels either, Friedman warns. After returning home from vacation, she recommends tossing all clothing into the dryer for 30 minutes on high to kill any blood-sucking hitchhikers.

Metal and plastic harbor bedbugs.

Although bedbugs prefer wood with its numerous crooks and crannies, metal and plastic furniture or items often contain tiny hiding spots as well, particularly if there are parts with open tubes. If you simply must buy an item at a second-hand store, Schal recommends putting it in the freezer if it fits. If not, covering larger items like furniture with a garbage bag and placing them in the sun all day should bake any critters.

Bedbugs travel stealthily.

Bedbugs can walk from one apartment to the next through water pipes or electrical, heat, and phone line conduits. To explore this thrilling possibility, check out light fixtures, electrical switch plates, and hidden spots near the sink and bathtub. Although increased travel has been blamed for the bedbug resurgence, the pests also seem adept to exploring your neighborhood on their own.

Bedbugs hiding in a screw hole on a plastic desk chair. Credit: Louis N Sorkin, BCE, Entsult Associates, Inc.

Another of Coby Schal’s projects involves tracing bedbug migration by isolating genetic markers from the bugs and asking whether multiple infestations on a city block result from a single colony of critters expanding their territory, or from numerous invasions by different bedbug populations hitchhiking on various residents.

Bedbugs don’t transmit disease.


Bedbugs aren’t lazy.

Don’t be fooled, moving to the couch for a solid night of rest will only encourage bedbugs to spread into the living room.

The bedbug explosion is real.

According to the National Pest Management Association, 95 percent of pest professionals reported treating bedbugs in the past year, up from 25 percent in 2000. Titles of scientific articles published this year read: "Bedbugs: The Worldwide Renaissance of an Old Partner of Humankind," "Easing Bedbug Anxiety: What You Need to Know about the Recent Bedbug Resurgence" and "They Only Come Out at Night: Bedbugs and Their Alarming Resurgence." Finally, hip graphic designers have captured the trend—Christian Swinehart created a stylish interactive map depicting the growing infestation in the Big Apple.

Misinformation exacerbates the resurgence. As Wong explains, "The problem is people are fearful and when they panic, they employ all sorts of methods that make the situation worse." Unfortunately, this trend may continue, as local health departments are ill-equipped to handle pest outbreaks. In a 2007 survey 74 percent of local health departments reported that they did not have sufficient numbers of public health workers to staff their vector control units (2). "There’s been a steady erosion of pest management capacity at the state and local level," says Michael Herring, senior environmental health scientist at the U.S. Centers for Disease Control in Atlanta. "A lot of people call on their local health department when they have pest problems, especially if they don’t have money for an exterminator," he says, but without a vector control program, a department has little ability to respond quickly to calls and to spread the message about integrated pest management techniques.

In sum, if you’ve decided to live in a neighborhood like mine, follow the simple tips above and hope for the best. If that doesn’t pan out, call a professional.


1. Environmental Health Perspectives’ "Invasion of the Bedbugs"

2. CDC’s "Where have all the vector control programs gone?"


About the Author: Amy Maxmen is a freelance science writer based in New York. She received her PhD in Evolutionary Biology from Harvard in 2006.

The views expressed are those of the author and are not necessarily those of Scientific American.


Note: original text stated that DDT "falls into the pyrethroid group". It does not, though it targets the same site as pyrethroids do. This error has now been corrected in the text.


Comments 20 Comments

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  1. 1. Soccerdad 12:30 pm 05/11/2011

    The resistance of bed bugs to DDT is a red herring. The resurgance of bed bugs occurred long after DDT was banned in 1972. It occurred in the mid 1990′s after EPA banned several pesticides like Malathion and Propoxur. The comeback of these creatures is entirely self inflicted and could be reversed simply by allowing these pesticides to come back into use.

    Link to this
  2. 2. Alvis 12:36 pm 05/11/2011

    How do you consider DDT a pyrethroid? I wasn’t aware of any structural similarities.

    Link to this
  3. 3. alandove 12:58 pm 05/11/2011

    DDT is not a pyrethroid.

    @soccerdad, EPA did not ban malathion or propoxur. Both are still used in numerous applications, including mosquito control. They are not, however, approved for indoor use because of their probable toxicity to people. Bringing them inside would cause more problems than it would solve.

    Link to this
  4. 4. RobLL 1:39 pm 05/11/2011

    Back in days when I did some pest control work, we were advised that the developing synthetic pyrethrims were likey reinventing DDT and Chlordine. We were not given any heavy chemical lesson and illustrations. Any chemist out there want to speak up?

    Link to this
  5. 5. RobLL 2:24 pm 05/11/2011

    grrr – ‘pyrethrums’, ‘likely’, wish we could edit for spelling.

    Link to this
  6. 6. AmyMaxmen 2:33 pm 05/11/2011

    Thanks for the careful read. You are correct, DDT is not a pyrethroid.
    However, it does act on the same molecular site that pyrethroids do,
    and therefore bedbugs are cross-resistant to DDT as it has the same
    mode of action.

    Link to this
  7. 7. V.E.LovesScience 7:15 pm 05/11/2011

    Just a thought, could a poisoned bait approach be researched and developed to add to an extermination program which would get rid of bedbugs. I would assume for complete extermination, an almalgamated cadre of approaches would be needed.
    If a poisoned bait is used to kill cockroaches which have a varied diet, and ants, could there not be a poisoned bait developed that would both kill bedbugs and nullify their eggs.
    A number of decades ago during an overnight stay in a hotel, I was bitten on both knees and legs by bedbugs and the next day my knees ballooned up from twice to three times their size. The bites and my legs were extremely sore and painful… an allergy and a very very painful experience. The current situation rattles me.
    Given the magnitude of this problem now, there needs to be a concerted effort to control and get rid of these bloodsuckers because if at some point they do develop a hitch hiker, a disease with deadly consequences, the situation will be overwhelming for city and state services for the United States and city and provincial services for Canada, and unbearable for those in the grip of this problem. I would think that bedbugs are indiscriminate in what hidey hole they crawl to or into to bleed you, eyes, nose, ears, etc… I would also think that a suffer’s quality of life would be shattered, and children deserve better than an insipid approach.
    These little guys puncture and insert their body part into the skin and they are not clean diners and it appears they are becoming impossible to stop.Hopefully we, the public, will not be sidelined by the ‘there’s not a lot that can be done’ mantra… and not be forced to roll over and play dead and accept our being bled in bed…

    Link to this
  8. 8. Richard Pollack 8:51 pm 05/11/2011

    Good article Amy. Misinformation exacerbates more than you describe. A surprising proportion of presumed bed bugs are not. Instead, many are innocuous insects of other kinds – or even bits of debris. Because many folks wrongly conclude that any bug they see on the bed must be a bed bug, they then embark upon an expensive, misguided and sometimes risky campaign to search and destroy the wrong villain. Before reaching for the spray can, reach instead for your digital camera to capture images of the culprits. Good digital images will allow for a rapid, confidential, independent and expert identification. Educational information about bed bugs and their management that I formerly hosted at the Harvard School of Public Health is now at Rapid identification resources are available there as well.
    -Richard Pollack, PhD (IdentifyUS LLC)

    Link to this
  9. 9. denysYeo 10:12 pm 05/11/2011

    I enjoyed your article. Here in the lower part of New Zealand bed bugs do not seem to be a problem – I think they exist but I can’t recall encountering even one. I wonder if there are geographical differences in bed bug populations? Maybe Google maps should have a bed-bug reporting button (as they do for some other things) and we could get a feel for bed bug activity around the world?
    Or even an iphone, report a bed bug app!

    Link to this
  10. 10. jimtanekr 3:38 am 05/12/2011

    I’ve already contacted a few University professors who are studying this problem to inform them of a potential culprit in this new bedbug infestation in the US. Our military.  I have just recently retired from the army and can tell you from firsthand experience that the living conditions in many of the locations that we deploy to are completely infested with bedbugs and other creatures.  As stated in the article, “Although increased travel has been blamed for the bedbug resurgence, the pests also seem adept to exploring your neighborhood on their own.”   It would be extremely easy for bedbugs to catch a ride on our kit from Afghanistan back to the States and then spread from there.  This is a completely feasible explanation as to why there is a resurgence in bedbug population.

    Does anyone know if any research has been done to see whether or not the specific species that is resurging in the US is native or a species possibly from the Middle East?  If so, this would probably be an important and timely paper to write.

    Link to this
  11. 11. Soccerdad 9:10 am 05/12/2011

    OK, these pesticides are only banned indoors where they could be used to solve the bedbug problem. One would think in a science related article that the truth would be told about the real cause of bedbug resurgance and not obfuscated with DDT resistance to avoid discussing that there are effective pesticides which could resolve the issue if permitted.

    Link to this
  12. 12. Elderlybloke 11:11 am 05/12/2011

    Here in Gisborne,NZ I have never heard of any bed bug infestations.
    Dust mites are the only thing I know of.

    Link to this
  13. 13. SBryks 1:23 am 05/15/2011

    Bed bugs do not feed on baits.. period!
    what is needed is good education.. that is what is missing more than anything else.

    Link to this
  14. 14. SBryks 1:26 am 05/15/2011

    This is very unlikely. Really a far-fetched red herring…
    This problem started many years ago, and it just indicates how well insects can adapt to changing circumstances. .
    I have never heard any suggestion it is linked to the U.S. Military in Afghanistan or elsewhere. The U.S. Military has more resources in entomology than any university in the world. If this were an issue, we would have heard it long ago.

    Link to this
  15. 15. SBryks 1:30 am 05/15/2011

    Studies by some researchers do indicate that the bed bugs found in U.S. are from African sources.
    More likely brought by travellers. Some studies have shown that major infestations can be traced to a very small number of first infestations – back to one or two or three single gravid females from DNA studies.
    but once they are established, then spread to other sites has increased through socialization and moves, as well as discarded furniture.

    Link to this
  16. 16. SBryks 1:46 am 05/15/2011

    As Richard Pollack noted there is a lot of misinformation, not only misidentification, but lack of understanding by tenants, landlords, and even pest control professionals about how to address the problem. CDC/EPA put out a joint statement last year late in the year, with emphasis on the importance of a societal response that incorporates Integrated Pest Management as the central model and approach to addressing the issue.
    In addition to an amazing amount of misinformation (even on this blog in comments), there is also a huge marketing happening with wild claims and promises that are largely "sales hype", with promises of "moneyback guarantees" that essentially put onus on consumer to return product at their own expense and lose "shipping and handling charges" that usually are the actual profits.
    the media also has a tendency to put out "hot" stories with a "bit" of information, but usually not enough.
    the most recent story about research on resistant bacteria and bed bugs as "possible" agents of spread has created more fear again. We have known about risk of skin infections by antiobiotic resistant bacteria due to scratching of bed bug bites for a long time. I first heard this reported in Toronto by street nurses helping homeless back in 1999, and earlier. The probability of bed bugs actually causing the infections is likely slight, as we have not seen an epidemic of skin infections in the general population, but when a homeless person who may also have mental health issues, or drug addiction (as noted in the Vancouver study), then the risk for poor personal hygience and infection through dirty needles, or simply scratching bacteria into broken skin from scratching itchy bites.. I think that experts in bacterial infections will indicate that there needs to be a certain minimum inoculum for the infection to overcome immunity, or if the victim has a compromised immune system. Review studies of bed bugs and disease have not shown a single case yet of a clear vectoring of infectious disease by bed bugs, not through a hundred years of awarness of infectious disease.
    Raises a lot of fears, but it probably not of significance for most people, but the risk of infection is there for vulnerable people.. with bed bugs as a contributing factor, but not the likely source of infection.
    We need more education and enforcement of good IPM practices to eliminate bed bugs..
    Media need to help more in this, than scare stories that are "hot" news.. but don’t help.
    Sam Bryks, M.Sc. Board Certified Entomologist
    IPM Consultancy, Toronto, Canada

    Link to this
  17. 17. melcall 11:05 pm 07/27/2011

    An older relative’s home recently became invested with bed bugs and ultimately these bugs got into our home as well. I found out that infestations are not a matter of hygiene…these things get transported!

    Now, I’m familiar with what they look like and I understand that identification is a major step in dealing with them. I turned to chemicals at the local store because I really didn’t know what to use. I really didn’t want to use them for fear of causing other problems resulting from using such harsh ingredients. And I found that bug bombs only spread the bugs further through out the house as the scatter to avoid the chemicals.

    Then I found a resource online which has products that are not made with chemicals and are supposedly safer to use (green) rather than using chemicals which can be harsh and dangerous, as you’ve pointed out.

    One of the most successful treatments recommended was the use of vacuums and steamers meant to kill bed bugs. These steamers can reach areas where bed bugs hide (cracks, seams, outlets, etc.) also they can be used on luggage, used furniture and clothing. Some steamers are quite expensive but this company has one for about $38. I think it would be a great item to pack when traveling these days, better than an iron.

    At first I was in a panic about these things since my wife was having a terrible reaction to their bites. Reportedly, their bites get misdiagnosed often. So,in order to protect ourselves it is important to become aware, diligent and be prepared to deal effectively with this bed bug outbreak.

    Here’s the company, maybe it will help you to:

    Link to this
  18. 18. msbuggedout 1:53 pm 10/3/2011

    Amy, you left out the #1 thing people need to know. Diatomaceous earth kills bed bugs and it’s cheap.

    WARNING – MUST BE FOOD GRADE. The other kind of DE is used in pool filters and is dangerous. Can cause silicosis of the lungs. Diatomaceous earth is a powder. Food grade DE is amorphous, pool filter DE is calcined and again, dangerous.

    All they have to do is touch the stuff. It cuts their bodies and dessicates them. It works on cockroaches too!

    Can’t understand why media and experts don’t trumpet. Well, some experts do, but not enough.

    It’s harmless to people and pets.
    It’s a mechanical killer so they can’t become immune to it.
    You can leave it out permanently (line your baseboards).
    It must remain dry – it loses efficacy when wet.
    It really works!

    I just knocked out a light infestation with it. Encased my mattress and box springs, lined my bedrails and baseboards.

    Amazing stuff – they’re dead and gone!

    The powder ca

    Link to this
  19. 19. Canklefish 4:39 pm 12/4/2011

    Oh, I bet the Boroughs are cleaning up on bed bug sprays…

    Link to this
  20. 20. Bluerunner2 7:40 am 02/24/2012

    DDT is an effective treatment and should be brought bacyk for use in getting rid of bedbugs.

    Link to this

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