I'm going to take a shot at this. I believe that when you see the word "glue" in connection with "bedbugs" the subject is "insect monitors" which are glue strips similar to glue mouse traps. The purpose of them is for exterminators to get an idea how many bugs are crossing a specific location within a specific amount of time.

In my humble opinion, this is of no value to the traveler who wants to know "Does my room have bedbugs?"

I have not heard of any reliable bedbug detection systems that are based on anything other than specially trained dogs, but that's just me.