Wednesday, February 14, 2007

Caulk, caulk, caulk!

So far it seems that I have been opposing the use of insecticides. But that simply isn't true. If we were dealing with cockroaches, then I would say, let's try not to use chemicals. But bedbugs are different, we must use any weapons available to get rid of them. To make strategies such as Rotation work effectively, we will need more insecticides than we currently have. Therefore, in my opinion, if the situation really gets out of control, the government may have no choice but to loose the restrictions on some insecticides. On the other hand, I do believe that it is very dangerous to be over-dependent on chemicals, mainly because of insecticide resistance. Many people believe that if we had DDT, we would have eradicated these bedbugs as we did in the old days. I highly doubt it due to the cross-resistance (knockdown resistance) between DDT and pyrethroids, especially if these bedbugs have originated from a region/regions where DDT or pyrethroids were heavily used. To defeat bedbugs with chemicals alone, we will have to unleash more powerful insecticides than just DDT.

As Deb, a member of Yahoo Bedbugger Group, pointed out after my last post, since bedbugs are mostly in the bed, they don't even need to cross the insecticides on the floor to reach us, and even if we did have access to some powerful insecticides, we wouldn't be able to use them freely in our beds. This is just another reason why we cannot depend completely on chemicals. By combining all weapons available to us, we will effectively improve our chance of winning. For example, if we have two pesticides with different modes of action and with no cross-resistance, each of which gives 70% of control, and two alternative measures, each of which gives 40% of control. By combining the two pesticides, we can theoretically achieve 1-(1-70%)2, or 91% of control. Similarly, by combining one of these pesticides with the two alternative control measures, we would achieve 1-(1-70%)x(1-50%)2, or 92% of control. And if we combine them all, then we would achieve 1-(1-70%)2x(1-50%)2, or 98% of control. In addition, resistance will become less of a problem since the bedbugs that are resistant to one control measure can often be eliminated by another.

Although they can provide temporary control, chemicals alone will not provide long term solutions. Because even if we have successfully removed an infestation today, when opportunity comes, bedbugs will invade our homes again, and we will have to repeat the same painful process of treating multiple times without any certainty of success and storing all our belongings in a storage unit for 18 months. To find a real solution, we need to get to the root of the problem. Yes, it's easy to bring home some bedbugs (or any other pests) accidentally, but they will establish an infestation only if we have a hospitable environment for them. If they cannot find what they need in our homes, they will either leave or die. Therefore, we should first identify the basic elements that bedbugs need to survive, and then remove them.

All insects need three things to survive: water, food, and shelter.

Most insects need water and moisture.

Mosquitoes need water to reproduce. There are two types of mosquitoes. Standing water mosquitoes lay their eggs on standing water, and the larval and pupal stages of all species require standing water to develop. Flood water mosquitoes actually lay eggs in moist soil. Since adult mosquitoes are mobile, hence eliminating breeding sites is always a preferable and more effective way to control mosquitoes. The eradication of malaria in North America is a perfect example of success through the use of an integrated approach. Breeding sites such as swamps, pools and wetlands were either drained or filled, oil was applied to water surfaces to suffocate the mosquito larvae, screening was used on windows and doors to keep mosquitoes out, and the National Malaria Eradication Program helped the final eradication of the disease through the use of DDT.

Since then, unfortunately, the global malaria eradication campaign from 1955 to 1969 has failed, and the Roll Back Malaria movement that started in 1998 is also failing. Today, malaria is re-emerging as the number one infectious disease. There failures have been caused by a number of factors, the most important of which is that not only has the vector (mosquito) developed resistance to pesticides, the malaria parasite has also developed resistance to the drugs used such as chloroquine. We were so confident that science could solve all our problems, so instead of working with nature, we have been forcing our way through with chemicals and biotechnology. But chemicals have limitations, so has biotechnology. HIV viral strains are now showing resistance to drugs that were once effective. A recent research also found that Gentrol, a popular insect growth regulator, caused no reduction in egg production and hatch.

Many insects are also attracted to areas where moisture accumulates. Subterranean termites need constant moisture to survive. Adequate ventilation can effectively reduce the opportunity for termites to build their colony. Cockroaches, silverfishes, sowbugs, pillbugs, springtails and booklices are also heavily dependent on moisture. Certain insects such as springtails and booklices can be eliminated by reducing humidity alone.

I haven't been able to find reliable information on how dependent bedbugs are on moisture. But at least one pest control company, Pestec in California, has conducted experiments on treatment using both heat and dehumidifiers. Insects thrive under some ideal conditions, and the ideal conditions for most insects are between 20 and 30oC (68-86oF) for temperature, and between 60% and 80% for humidity.

Insects of course also need food to survive.

Bedbug's food is, unfortunately, our blood. According to BBC Science & Nature, Bedbugs are believed to have originated from the Middle East where they fed on bats living in caves. "Man moved into the caves and when they moved out, the bugs, which had adapted to feed on them, went with them". What a mistake we have made! But as I have suggested many times in the past, bedbug's dependence on our blood is also their weakness. Since I have emphasized enough on "why and how to protect ourselves", I am going to skip it this time. You can read my previous posts for both theories and some practical advices.

Finally, insects also need a safe place to live.

As we all know by now, bedbugs live in cracks and crevices. They also try to be as close to us as possible. So the first choice is the bed, and the next is the chair or the couch. It is possible for them to travel some distance to feed, but this is not preferable, since it will make them not only easier to be detected, but also consume energy. Also, by staying close to us, nymphs will be able to feed immediately after hatching.

I mentioned caulking quite a few times in my previous posts. To understand the importance of it, let's first take a look at the extermination process. The preparation work required by a pest control company often involves moving the furniture away from the wall and removing all bedding and all contents from the closets and the drawers. The purpose of this is to enable the PCO to access all possible hiding places and treat them with insecticides. Insecticides can be classified based on active ingredient, mode of action, method of application, and so on. The WHO even has a classification system based on hazard. PCOs often classify insecticides by method of application, and hence we have Crack and Crevice application, Indoor Surface application, and Indoor Space application. If you are lucky to have a properly trained PCO, then he would use Crack and Crevice application, such as insecticide dusts, for areas that are difficult to reach, such as deep cracks and crevices (some PCOs may even drill holes in the walls to apply insecticide dusts for long term control), Indoor Surface application (usually residual sprays) for areas where bedbugs are most likely to crawl in, and Indoor Space application (aerosols) when harborages are found. Most qualifies PCOs should know how to apply the pesticides. The most challenging work, however, is not how to kill the bedbugs, but where to find them, and I believe that knowing where and how to find all the potential harborage sites is one of the most important characteristics that distinguishes a good and experienced PCO from the rest.

Simply put, a PCO's job is to identify all the potential harborage sites and then treat them with insecticides. What puzzles me then, is how efficient it is to keep vacuuming and treating the same cracks and crevices over and over again. Since the harborage sites have already been located, why not take one step further and remove them by sealing them all? Currently used residual insecticides can last a few months at most before they break down, but caulking can last decades. Even if we are lucky enough to remove the infestation this time, as long as these cracks and crevices exist, our homes will always be vulnerable to future re-infestations. Instead of keeping vacuuming and treating the same cracks and crevices, why don't we caulk them all? By doing so, we will eliminate not only all the bedbugs inside, but also these potential harborage places. Assuming that you are able to locate all the cracks and crevices in your home, then theoretically you can eliminate the whole infestation by caulking alone, and you will also end up with a bedbug proof home. For extra safety, you can always apply insecticides before caulking. Yes, you may still accidentally bring home a few bedbugs in the future, but they will not be able to spread to your neighbors, escape the insecticide treatment, or hide somewhere close to you to wait for a chance to attack you. They will have no place to hide and it will be a lot easier to locate and remove them.

It is true that caulking a whole residence takes a lot of time and efforts. But is it any easier to vacuum and treat all the cracks and crevices over and over again, in addition to all the preparation work for each treatment? A real solution is never an easy one. Many people must have thought that it was ridiculous and mission impossible to install screens in every household and to eliminate every single pool, swamp and wetland. But we have done that, and we are lucky that we have done that. On the other hand, it's not as hard as it seems to eliminate all the potential harborage places. Many things that I have done in the last few months can be done systematically and with much less time and efforts. Firstly, there is money to be made. Sooner or later we will see bedbug proof furniture that have all the joints sealed and have polished metal legs. It took me about half an hour to thoroughly caulk my chair. But manufacturers only need to apply a thin coat of finish to seal all the joints, which shouldn't cost more than a few dollars. Secondly, new legislation and regulations need to be introduced. If your bathroom or kitchen has recently been renovated by a professional, then it probably has also been caulked. This is for energy saving as well as for pest control and is becoming a standard practice. If caulking can be done to the bathroom and the kitchen, then why can't it be done to the bedroom and the living room? It should be made mandatory to have the baseboard caulked before a house can be placed in the market, to have the gap between the light and the ceiling caulked after a ceiling light is installed, and to have bug-proof cover installed on all electric outlets (child safety electric outlet covers are available but I am not sure if they are tight enough to keep bedbugs out). There are many improvements that can be made to our homes and will only add a tiny fraction to the price of a house. There may also be better technologies and easier ways than caulking to eliminate the potential harborage sites for bedbugs. It's not technology or resource that we are lacking. The Centers for Disease Control and Prevention (CDC) was originally founded to combat malaria, we need the same kind of commitment and determination from ourselves as well as from our government to win this war against bedbugs.

As you can see, it is not difficult to figure out the importance of caulking. But while everyone is talking about all kinds of insecticides, very little attention has been given to simple, cheap, but effective measures such as caulking and the use of boiling water. Is it because we are so used to complicated chemical compounds and high-tech devices that we no longer pay attention to all the simple things, and since the sophisticated chemical formulas failed us, we automatically assume that simple measures such as caulking will not make any difference? Or do we just feel that it's safer to follow what everyone else is saying, and to not suggest any new ideas, to avoid the risk of being laughed at by others? Whatever the real reason is, if after spending hundreds or even thousands of dollars we still cannot eliminate one single infestation, then I just don't think that we are doing it right. I am not suggesting that caulking alone can completely solve our problem. As always, I prefer a well-planned strategy that consists of a variety of control measures. But caulking, or eliminating the potential harborage sites for bedbugs to be precise, should definitely be a major component of that strategy.


Anonymous Nobugsonme said...

Very comprehensive! Nice work!

10:34 PM  
Anonymous Anonymous said...

Ok, figured it out.
Can you please explain how boiling water works to combat bed bugs while also caulking? Thank you.

8:12 PM  
Blogger Frank said...

Anonymous said...
Ok, figured it out.
Can you please explain how boiling water works to combat bed bugs while also caulking? Thank you.

I have answered your question on, as copied below:

Sorry to cause you confusion. The use of boiling water has nothing to do with caulking, I was only suggesting it as another alternative control measure.

Heat treatment may be more effective than we originally thought. According to some recent experiments by Dr. Michael Potter, both washing and drying on hot settings killed all stages of bedbugs. In his experiment, it only took five minutes to kill all the bedbugs in a clothes dryer at 175 degrees Fahrenheit. But this is only one single experiment, some individuals may be more resistant to heat than others. Just to be on the safe side, I would suggest you to do a full dry cycle.

The thermal death point for bedbugs is 45 degrees Celsius, and the temperature of boiling water is 100 degrees Celsius. Therefore, in my opinion, boiling water is more lethal than any pesticides, but of course, it has limited applications. I used it on my chair and vacuum cleaner. You may even use it to treat your furniture and bed frame, but don't use it on anything expensive, especially the outside surface, since it might cause damage to the finish.


8:02 AM  
Blogger Frank said...

One last thing that I would like to add is that, just because I suggested the use of boiling water as an alternative measure, does not mean that you should start pouring boiling water on everything, because it could potentially injure yourself, damage the item, and excess humidity could lead to other problems such as dust mite and mold growth, and provide hospitable environment for many pests.

7:56 AM  
Anonymous nyjammin said...

This is nyjammin. Hello, Frank. I have questions and comments. First of all, how did our ancestors dispose of bedbugs? Do you think that they had vacuums and steam cleaning and did they double-bag everything? I think not. Poor people used to sweep everything and vacuuming was only for people who had wealth. What about washers and dryers? Did our mothers and fathers have those? Probably not. We have so much new technology these days that we are using and the bedbugs still come back. I believe we need pesticides that were used from the 1950s until they were "outlawed" in the 1970s. We need to douse these little critters in poison. I truly believe that is our answer. We need to bring back older pesticides that actually work and we need to exterminate our houses every month until there are no more. I have no facts, but this is my opinion. Do you think that our mothers and fathers had alot of education like we do. I do not think so. A lot of us are first generation high school and college grads. So, with our mothers and fathers so uneducated and having limited technology, how did these little critters almost disappear? The government needs to get involved and only then, I believe, will these bugs begone us.

5:31 PM  
Blogger Frank said...


Correct me if I am wrong, but I think the old pesticide that you referred to was DDT.

There was discussion about DDT that led to personal attack on the Yahoo Bedbugger message board in the past, and that was the reason why the board is being censored. There was heated argument about DDT on recently, and the site owner had to close the thread.

I totally understand some people's desire to find a quick and easy solution to this bedbug epidemic, but it becomes dangerous when they get so obsessed with their own conclusion that is based on personal opinion and preference, while ignoring all the facts and experts' advice, since any inaccurate information will only mislead others and make a bad situation worse.

I have no intention to start another discussion about DDT here. You can see this latest discussion on Bedbugger yourself:

I might talk about DDT briefly in my next post on heat and cold treatment. For the time being, just keep in mind that while there has been controversy over DDT's side effects, there has been no controversy over DDT resistance. That is a fact.

By the way, without education and knowledge, we wouldn't have had DDT in the first place. And had we had some knowledge and education about pesticide resistance, we wouldn't have used DDT the way we did, and it might have remained a very effective pesticide today.


10:22 AM  
Anonymous nyjammin said...

Frank, thanks for referring me to the blog on DDT. I want to apologize for I did not even realize that there were arguments so drastic about DDT that an actual web site had to be closed. But, sometimes people need to fight for the good of the people. Sometimes fighting solves and educates people. I mean fighting without violence or obsenities is healthy. People should not insult or judge anyone. We are all in this together, trying to fight one cause.

2:10 PM  
Blogger nyjammin said...

Frank, what kind of caulking did you use. I used the silicone caulking, clear and it takes almost 2 days to dry. I did the metal bedframes and I also did parts of my wood floors but the caulk dries to a rubbery hard and I want something less rubbery. My wood floors became sticky when I tried to caulk them. I was wondering what do I use on them? Polyurethane is so much work done by myself (my whole 2 bedroom apartment has wood floors) and too expensive to have someone else do it. What do you recommend for caulking around window sills, etc. Thank you.

3:35 PM  
Blogger Frank said...


I would recommend wood filler and Polyurethane for wood floor. Fill the big gaps with wood filler first, and then cover the small ones with Polyurethane.

I almost used latex caulking exclusively. The only place that you might want to use silicone caulking is the kitchen and the bathroom, since silicone withstands extreme temperature better than latex.

For windowsills, I used clear latex caulking. It becomes almost invisible once dried.


8:12 AM  
Blogger nyjammin said...

Frank, so I don't have to polyurethane the whole floor just the cracks? Can you please give a manufacturer who makes wood filler or do I just go to the hardware store and would they know? Thanks.

11:50 AM  
Blogger Frank said...


You do need to do the whole floor. Polyurethane is like paint, it forms a durable coating and consequently covers all the small cracks. There are oil-based and water-based urethane. Oil-based urethane is more durable, but has strong odor that could last for days or even weeks. You can do one room at a time.

For wood filler manufacturer, it is better to ask your local hardware store. But be sure to get one that matches the color of your floor.


1:14 PM  
Anonymous nobugs said...

Hi Frank!

It took me a long time to see these comments. I just want to clarify that the DDT thread on was not closed because of the heated nature of debate. It could have been, but wasn't. I ended it like this:

"Nobody's in trouble, everyone's okay, right? Maybe the pied piper will help us "move on." get it? ;-)

I am closing this thread because it's gotten pretty long (did anyone else hate clicking for page 2, or am I just lazy?) and Bugalina asked me to. You can talk about DDT again when you're inclined, but just start a new thread."

Yes, there was an uncivil tone which people were asked not to engage in. But the thread had also gone from being about the issue to being about how the issue was being discussed. So I did ask people to start a new thread if they wanted to say something more about DDT. No one took me up on it.

I think that's a good thing, and I think you're right that peoples' passions about DDT get in the way of a factual discussion.

Anyway, I hope you are not thinking much about bed bugs now, and are enjoying life thoroughly. We often refer people to this site, especially your wonderful advice on caulking.

Any suggestions for something that can be used to seal the spaces around heating pipes?

thanks again,

6:39 PM  
Anonymous Anonymous said...

Hi, thanks to everyone for the posts. I'm moving from an infested apt, which has been treated and will be treated again (so far no bites), and wanted to save my wooden furniture. I had thought I would use wood filler and polyurethane, so I was glad to see your post. But have you tried it? Will it definitely kill everything?

9:56 AM  

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