hello

I didn't find any thread on the forum about the use of what is called "the building-frame" in the Storch book "At the hive entrance"

I found Some french-speaking pages (google translation is a false friend!)
here on Lang sized hives and here

and one in a Warré hive

In french it's called "cadre-témoin" , what may be translated something like "control-frame " or "inspection-frame"

It is used tho observe the hive evolution during the year, anticipate the swarm fever, and as a varroa mite bait or trap as it produces mainly drone cells in season.

Does any body has a report or another reference ?