Will we ever… get rid of bed bugs?

Will we ever… get rid of bed bugs?

By Brooke Borel
Will we ever… get rid of bed bugs?(Copyright: Science Photo Library)

Many countries have seen a surge in infestations of the bloodsucking pest over the past decade. Brooke Borel examines what’s needed to tackle the re-emerging threat.

 

 

Why do we need to sleep?

 

 

Nothing makes the skin crawl more than the idea that tiny bloodsucking bugs could be living in our bedrooms. Around the size of a lentil, the common bed bug*, Cimex lectularius, can drink up to seven times its own weight in blood in one feeding, leave nasty, itchy bumps on their human hosts, and hide unseen for months on end.

Since the late 1990s, the bed bug has become an increasingly common urban nuisance in homes and hotels worldwide. A 2010 survey from the University of Kentucky and the National Pest Management Association found that 95% of US pest control companies had treated a bed bug infestation in the previous year, up from 25% a decade before, and 11% before that. Only last month, New York’s Department of Health and Mental Hygiene, a resource for other people with bed bug infestations, had to fumigate one of its floors.

According to the survey, the majority of pest control operators from Europe, Africa, Australia and North America said bed bugs were the most difficult insect pest to control, more so than ants, termites and even the formidable cockroach. Another study showed that in London alone, bed bug treatments grew by a quarter each year between 2000 and 2006.

The worst aspect about this is that we thought we had tackled the bed bug problem before. Clive Boase, a pest management consultant in Suffolk and author of the London survey, says that UK bedbug numbers began decreasing in the 1930s, thanks to changes in social housing and public health policies, which led to the demolition of old publicly-funded housing and teams of inspectors checking homes for vermin, respectively. New pesticides introduced in the 1940s, including DDT, also helped to bring numbers down, and by the 1950s infestations were rare. The US saw a similar drop in infestations from the late 1940s onwards, thanks to the advent and widespread use of DDT and other chlorinated hydrocarbon pesticides.

So, where is the chemical cure this time around? Or, is there any relief to be found in the myriad bed bug products and services on the market, from growth regulators to heat treatments?

Fighting resistance

The pesticides currently available, says Dini Miller, an entomologist and bed bug expert from Virginia Tech, are “not practical to use in a widespread way because of the cost.” New, cheaper pesticides are too expensive and time consuming to develop, she adds. Because bed bugs live primarily in the bedroom, chemical companies must provide extensive toxicity data to prove it is safe for indoor use, as it might come into contact with people or pets.

But, proving that a pesticide works and is safe could cost a company up to $256 million over eight to ten years for each active ingredient, according to a 2010 industry study conducted for Crop Life America and the European Crop Protection Association. The investment may not be worth it. The US accounts for over a fifth of the world’s pesticide use, the vast majority of which is used in agriculture, followed by herbicides and then insecticides. Compared to the vast expanse of farmland and orchards, the real estate of all of the apartments and houses in the world combined is small and brings in less money, says Miller. This is especially a problem considering patent protection on a novel ingredient runs out after around 20 years, after which the tech is open to generic competitors.

Even if making a new bed bug insecticide were lucrative, there are other challenges. There is the problem of figuring out how a chemical has to function in order to best kill bed bugs cheaply, efficiently and safely. This requires intimate knowledge of the bed bug’s basic biology. But, because bed bugs were at such low levels for decades, interest in studying them waned. Starting in the early 2000s, once it was clear the resurgence was real and that bed bugs weren’t going anywhere, scientists had to relearn bed bug basics from scratch, starting with fundamental aspects as how to raise them in a lab.

Then there is the problem of paying for the research. While dozens of labs now work on the basic science of bed bugs worldwide, funding remains low in part because bed bugs are not known to spread disease.

Finally, there is the problem of insecticide resistance. Even DDT, the supposed miracle cure, wasn’t immune to this. Five years after the pesticide was in widespread use in the US, DDT-resistant bed bugs popped up in Hawaii; in the 1950s and 1960s, resistant strains were found elsewhere in the US and in Japan, Korea, Iran, Israel and French Guiana, to name a few.

No chemical insecticide is immune to resistance, particularly if it is overused. Today, roughly 90% of bed bugs have a genetic mutation that makes them resistant to pyrethroids, a class of insecticides commonly used for bed bugs that work in a similar way to DDT.

Stopping spread

So, chemicals are not the sole answer. Neither, it seems, are any other options when used alone. “There is no silver bullet,” says Michael Potter, an entomologist from the University of Kentucky. Still, chemicals and other tactics can be used in an integrated pest management strategy, where they are sometimes used sparingly along with heat treatments (bed bugs die at 45C), desiccants such as silica gel and diatomaceous earth that fatally dry the bugs out, or vacuuming and getting rid of clutter.

Biological tactics are emerging as another possible option. Insect growth regulators, or IGRs, are chemicals that prevent bed bugs from completing their lifecycle, stunting their growth so they can’t reproduce. But, IGRs are slow-acting, and the bugs will still bite even if they can’t breed. On the horizon, perhaps, are genetically modified versions of symbiotic bacteria that live in the insect’s gut, including Wolbachia, which may be exploited for pest management. Or, the bugs’ pheromones, which tell them where to go and who to mate with, may also be reengineered and used against them.

In the meantime, public awareness measures can keep bed bugs from spreading. Good practices include: checking hotel room beds before unpacking, being mindful of belongings like a coat draped carelessly on an unknown couch, washing clothing in hot water and vacuuming suitcases after travelling, and avoiding discarded furniture on the street. Some experts also recommend sealing mattresses and box springs in encasements specifically intended to keep away bed bugs, which may make the bed easier to treat and could save it from permanent damage.

These combined efforts have knocked down infestations in some areas, says Boase, particularly among high-end hotels and the rich. Both can afford to throw money at the problem. Right now, he adds, the most severe infestations in the UK are in low-income housing – not because poor people are more apt to get them, but because they are less likely to be able to afford the treatments. The US has a similar problem. Better control will depend on cheaper, more efficient options entering the market.

“I feel that it is possible to bring infestation levels down in that residual housing area, but we don’t have the tools of infrastructure to support it,” says Boase. Then again, he says, “we’ve never had [total] eradication before.” But, with cheaper tools, we may be able to knock bed bug levels back down everywhere. Or at least, he adds, “we love to think we can.”

* Many people write “bedbugs”, but entomologists use two words when describing Cimex lectularius, because it is a “true bug” (Hemiptera). Entomologists always use two words for insects that are true to the common name they have – so for example, house fly is two words because those are actually flies, but butterfly is one word because they aren’t flies.

 

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Scientists have discovered how mosquitoes develop viral immunity

Scientists have discovered how mosquitoes develop viral immunity, a breakthrough that could lead to better vaccines against mosquito-born viruses such as dengue and West Nile. The new study found that a protein called Vago is released by infected mosquito cells to warn other cells to defend against invading viruses. This is the first time such a mechanism has been found in mosquitoes or any invertebrates.

NPMA Announces Pest Photo Contest Finalists

NPMA Announces Pest Photo Contest Finalists

The National Pest Management Association (NPMA) has announced the top ten finalists in its second annual Pest Photo Contest, a national online competition that challenged photographers to submit images of common household pests, rodents and small wildlife.

To enter, photographers – amateur and avid alike – submitted their favorite pest photos to the PestWorld Photography Contest group on Flickr.

All entries were judged on criteria including originality and creativity, adherence to creative assignment and overall appeal.

The NPMA received almost 500 stunning pest photos from talented photographers around the world.

Check out the ten finalists, listed in no particular order:

Bumble Bee by Steve Pidan

 Bumble Bee by Steve Pidan

Carpenter Ant by t.alley

Carpenter Ant by t.alley

Cicada by Mary Faber

Cicada by Mary Faber Photography

Dragonfly

Dragonfly by rockstarblu

Fly by Olympus&NikonianRay

Fly by Olympus&NikonianRay

Fly Eyes by tle73

Fly Eyes by tle73

Grasshopper by modgilla

Grasshopper by modgilla

Hover Fly & Spider by SHAUN>D

Hover Fly & Spider by SHAUN>D

Unknown Spider by Maxwell Rocha

Spider by Maxwell Rocha

Wheelbug by Bug Zero

Wheelbug by Bug Zero

Which one do you like? Tell us in the comments below!

UF Study Reveals Bed Bug Feeding Patterns

UF Study Reveals Bed Bug Feeding Patterns

Researchers at the University of Florida examined the feeding patterns of bed bugs — and the impact they can have on humans’ blood after several months. Their research was published in the journal Medical and Veterinary Entomology. Via: PCT

Researchers at the University of Florida examined the feeding patterns of bed bugs — and the impact they can have on humans’ blood after several months. Their research was published in the journal Medical and Veterinary Entomology.

The study shows that bed bugs will have a bigger or a smaller bloodmeal depending on when they last fed. For example, if bed bugs are fed every day, they have 1.5 times fewer instances of eating than those only fed occasionally, researchers found.

Researchers also found that production of bed bug eggs is linked with how much blood the bed bugs were able to consume the week prior.

“Longer and more frequent feedings increased egg production, which would allow a faster growth of bed bug populations,” they wrote in the study. “The increase in bed bug populations obtained with more frequent and longer feedings can be the difference between a population that barely survives at a location and a thriving population.”

Researchers conducted their study by letting bed bugs feed on chickens (both chickens and humans are known to be great “feeding hosts” for bed bugs).

Download the article at
http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2915.2012.01057.x/abstract.

Cockroaches 101

Educational – Cockroaches 101

Missy Henriksen with the National Pest Management Association discusses cockroaches and provides tips to help you keep these pests out of your house.

The Truth About Bed Bugs & Health

The words “bed bugs” tend to evoke many unpleasant feelings and the idea of being in the proximity of these pests can often send people running. However, as bed bug infestations have become more commonplace in the past few years, it is important to know why bed bugs are drawn to us and what implications these blood-sucking pests have on human health. Here ten important bed bug facts to know.
Read more

2012 second-worst year ever for West Nile virus

2012 second-worst year ever for West Nile virus

by Elizabeth Weise

8:34PM EDT October 17. 2012 – West Nile virus cases in the U.S. hit 4,531 as of Tuesday, including 183 deaths, making 2012 the second-worst year ever for the mosquito-borne illness, the Centers for Disease Control and Prevention reported Wednesday.

Cases were up 8% from last week, to 282, including 15 more deaths reported, said Erin Staples, a West Nile expert for the CDC. The numbers don’t represent a new wave of mosquito activity, but rather cases slowly working their way through to the CDC, she said. “It’s a reporting lag. We’re not hearing from our state partners that they’re getting a deluge of cases.”

It can take several weeks from when a person feels ill, goes to the doctor and then is tested for West Nile virus. Next, the report must go to the local health department and then to the state health department, which reports it to the CDC. The CDC then updates its numbers weekly, on Wednesdays. “So what we’re seeing is probably illnesses that occurred in September,” Staples said.

The peak of the disease appears to have hit at the end of August, when cases were going up as much as 35% a week. “As the cold weather sets in, particularly in the North and then moving south, that will stop the mosquito activity and then decrease the number of cases,” Staples said.

The state that has been most affected is Texas with 1,580 cases, of whom 55 died. California is next with 285 cases and 11 deaths.

So far, 2012 has surpassed all years but 2003 for the number of cases. In the past week, it surpassed 2006 and it beat out 2002 the week before, Staples said.

Most people infected with West Nile virus will not have any signs of illness, but 20% will experience mild symptoms such as fever, headache, body aches and, in some cases, a skin rash on the trunk of the body and swollen lymph glands.

People older than 50 and those with compromised immune systems are most at risk. About one in 150 people will get more severe symptoms: headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis.