Here in southern Ontario I often use auger hole entrances of 7/8 or 1 inch diameter. Many are at least partially closed in with propolis, a few to the point that there is only a hole a bee can pass through.  They are rarely  completely covered, but I have seen it happen. It may be significant that in two instances where the holes were not on the front side (or back) that these were completely propolized over.
Also, I have some boxes without bottom entrances, but only the auger holes with a notched inner cover. I don't think that these are ever propolized.

Re Gene's comment about Caucasians. I once got a few of these queens and they were remarkable for both the amount of propolis put down but also for the huge amount of drone brood.  For years i could track whether a colony was descended from these queens just by looking for these two things.

stephen

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