I treated a severely infested suite for bed bugs two weeks ago. At that time the tenant had installed 4 small clear plastic/glue monitors between the mattress and box spring. They are designed to entice the bugs into a small space and then are caught in a glob of glue in the middle of the plastic. I inspected a few of them and found nothing in them. I threw them on the floor under the bed as garbage and installed my own modified glue boards under each of the four bed legs.
I returned two weeks later for a retreatment and found the tenant had abandoned the bedroom – I was not happy as my glue traps are much less effective without active bait on the bed. I inspected the traps and my glue boards still had 59 bed bugs. I then inspected the four clear plastic/glue monitors and found 4 bugs. As such my day was not a total loss. I was able to compare my modified glue boards to the clear plastic/glue monitor in a severely infested room. And the clear plastic/glue monitor was found lacking.
So once again we see that just because someone markets a product (at more than $3 each) does not make it particularly effective. A 50 cent glue board vastly outperformed the fancy clear plastic/glue monitor.