Dr. Gerhard Gries, Ph.D., Professor at Simon Frasier University, Burnaby, BC, Canada
Bed Bug University—2015 Bed Bug Summit
“Uncovering the Secrets of Bedbug Pheromones and Communication”
Dr. Gries earned his Ph.D. in 1984 from George-August University in Germany. In 1991, he became a professor at Simon Frasier University and in 2000, he was promoted to full time professor of Animal Communication Ecology & Biological Science. In 2004, he was added to the board of directors for NSERC, Industry Research Chair, Insect Ecology. He has published over 230 research articles and peer reviewed journals and thirteen scientific insect films in Germany. As a professor, he runs a large lab with 13 graduate students, 3 research associates and several undergrad students. He has received nine million in research grants.
Bed Bug Bites — Research
You may have seen the article about the 200,000 bed bug bites that biologist Regine Gries (the professor’s wife) endured in order to study live bed bugs. She would feed 1,000 bed bugs once a week and did this for five years so that their research team could study them and find a true lure that would help people detect if they have bed bugs.
Beg Bug Bites and Disease Transmission
For years, bats have been in caves where they are bitten by bedbugs. Some early people also lived in caves and when they moved they took some of the bedbugs with them. Currently bed bugs are not considered to carry diseases, but last year Penn State showed that bed bugs can transfer Chagas (a disease which causes heart and digestive problems), but very rare. Overall, they still feel that bed bugs do not carry diseases like malaria, yellow fever or Elephantiasis. The belief is that bed bugs squeeze out most of the pathogens when feeding or that their immune response kills any bad pathogens. If this last statement is true then that opens up a whole other field to research and learn from on how to filter out bad bacteria and viruses.
Bed Bug Infestations
He asked why the increase in bed bug infestations and then mentioned that people keep moving “to jobs” and are either bringing them with them or moving into a place with them. He also mentioned the most common method which is the amount of traveling that is done by our society via vacation, public transit, buses and traveling abroad. Later he also mentioned the problem of bed bugs in second hand furniture.
Dr. Gries recalled one of many of his bed bug experiences in which he knocked on the man’s door and the guy actually had bed bugs crawling on him as the place had a total and structural infestation. He said he was actually afraid to shake the guy's hand, but he did. He said this was one of the jobs in which he actually did catch bed bugs from being there. The tenant was also a diabetic and would go to see the doctor on a weekly basis via public buses. The tenant also enjoyed going to the library a lot. Both of these activities spread bed bugs throughout the community.
Another story that Dr. Gries recalled was a case in which a family that was known to have bed bugs was seen placing their couch on the street with two signs on it. One sign had “Free” and the other sign had “Beware of the Bed Bugs”. The next day he noticed it only had the one sign “Free”, but the other sign was missing. Before he could deal with it, someone came by and picked up the couch.
Beg Bug Spray
Bedbug resistance to chemicals has been occurring for a long time. He said that in the old days people use to buy mercury chloride and put it on feathers to apply into cracks of baseboards and furniture. Mercury chloride was “bad stuff” so they stopped using it. There was also fumigation via Hydrogen Cyanide, which was excellent at killing bed bugs, but as the name implies deadly if inhaled by humans. Along came DDT and when compared to those chemicals it was considered safer and was very effective at killing bedbugs. It almost wiped them out, but the few that survived DDT were known to become resistant to it. These days we have new pesticides that are more Earth friendly aka “pyrethroids”, but as with all chemicals, over time, bed bugs are becoming resistant to these.
How To Check For Bed Bugs — K9 Bed Bug Detection
Researchers began looking at ways to “early detect bed bugs” because it is a well-known fact that early detection is the easiest way to eradicate bed bugs. Dr. Gries stated that “sniffer dogs” are one of the best ways to prevent full-blown infestations because they find bed bugs early, before they can make a stronghold in a dwelling, but he explained that the K-9 Inspections can be costly and therefore many may not be able to afford these inspections.
Bedbug Trap
This got them to thinking—what’s needed is a good bed bug lure and trap which would be safe yet inexpensive. Much research has been taking place trying to find the perfect bedbug lure/trap. They worked on incorporating “our smells”, such as sweat smells into lures. They placed carbon dioxide in the traps, but these only release for around 4 to 6 hours. They tried adding a warming component to the lures to emulate our body temperatures. One of the products that came out of this research is called “Night Watch”, but a drawback is that it is expensive and the carbon dioxide only lasts six hours not days on end, as is needed to be truly effective. His conclusion was that most bed bug traps are expensive, challenging, and their effect is short lived.
Researchers have begun to study bed bug signals and how they communicate and how this could be incorporated into lures. Dr. Gries was funny when he said, “bed bugs are quite horny”, but then explained that not only will male bed bugs use traumatic insemination (their thingie tears into the soft abdomen of the other bed bug and releases sperm) to impregnate female bed bugs, but that they will also do this to male bugs as well as nymphs which are the young bed bugs. Both male bed bugs and nymphs will sound a stress alarm when this rape occurs and the alarm is a blast or signal of pheromones. These pheromones communicate to the other bed bug “leave me alone” and as such are considered “repellent pheromones”. Since we don’t really want to repel bed bugs into the walls and into other areas this pheromone would not make for a good trap. There are also sex hormones which are signals that female bed bugs send out when ready to mate. This isn’t a good option because the lure or trap would only entice male bed bugs and it is the female bed bugs that are carrying the eggs and reproducing the colonies. There is a pheromone which appears to send out the signal “here is a good safe hiding place” and this would make for a good lure in drawing bed bugs to it. The team began to study this aspect in hopes of finding a decent trap.
Bed Bug Research — How They Communicate
Researchers have begun to study bed bug signals and how they communicate and how this could be incorporated into lures. Dr. Gries was funny when he said, “bed bugs are quite horny”, but then explained that not only will male bed bugs use traumatic insemination (their thingie tears into the soft abdomen of the other bed bug and releases sperm) to impregnate female bed bugs, but that they will also do this to male bugs as well as nymphs which are the young bed bugs. Both male bed bugs and nymphs will sound a stress alarm when this rape occurs and the alarm is a blast or signal of pheromones. These pheromones communicate to the other bed bug “leave me alone” and as such are considered “repellent pheromones”. Since we don’t really want to repel bed bugs into the walls and into other areas this pheromone would not make for a good trap. There are also sex hormones that are signals that female bed bugs send out when ready to mate. This isn’t a good option because the lure or trap would only entice male bed bugs and it is the female bed bugs that are carrying the eggs and reproducing the colonies. There is a pheromone that appears to send out the signal “here is a good safe hiding place” and this would make for a good lure in drawing bed bugs to it. The team began to study this aspect in hopes of finding a decent trap.
Getting Rid of Bed Bugs — Building a Better Bed Bug Trap
As the team worked on the research they began to look at the “castings” aka “cuticles” which are shed by bedbugs after they have fed. The research showed that when bed bugs can actually touch these castings they would notice the pheromone that sent the message “this is a safe place and there is food close by”. They then put these castings with a solvent known as methane extract and then drew off the fluid from the mixture. This was then studied thru nuclear analysis. They also looked at what humans produce when attacked by pathogens and found that the bioassay is “histamine”. They placed human histamine on a piece of cardboard, but found that it had 0% effect in luring bed bugs. They also tried bed bug feces, but this poop dries out over time and then has little smell to it, just like dog feces. Then they impregnated one end of cardboard with the casting extract and the other side with the human histamine and this combination with the pheromone seemed to work better. They found that they needed both the pheromone attractant and the histamine to get the lure to work. They could not find histamine in human blood, but found that certain amino acids that bed bugs breakdown appear to breakdown into histamines. The also knew that is used to capture blowflies and decided to test it on bed bugs. The results are listed below:
Credits: The following excerpt was taken from a Facebook share: Parents for Students Safety
Scott’s chemicals are working in partnership with Dr. Gries and his research team to continue to study this trap and evaluate its effectiveness at luring and capturing bed bugs. In conclusion, there is still many issues to address as we continue to combat bed bug infestations, but many new interesting studies are being conducted to help society deal with these pest.
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