I didn't mark the time in the video, but he mentions that the whole intent is to make it such that the beetles can't just land on the board like jumbo jets and scurry right into the hive. Several folks have noted their observation that SHB supposedly can't hover upward, so since this design requires hovering to enter, it resist beetle. Several other people have mentioned success using a PVC "snorkel" that was sharpened on the edges, so the hard-shelled beetles can't just land on the side of the hive and walk down the snout and turn-the-corner rand walk right in. Presumably if their shells are hard (and their legs are small enough), then they can't "bend" in the middle to make it around the end of the snorkel, and they'll fall off. He even made his from red plastic, and the folks that make the "Guardian" entrance blocker claim that beetles don't like red for some reason either.
Here is a quick section view of the design I am trying, it's 80% on the bench right now. There is another post about "vertical hive entrance" in the same forum that discusses it. It seems the consensus is that hive beetles are like squirrels, they're going to find SOME way to get in eventually, so it'll take a strong hive to resist them anyways. Ultimately personal experience for you will be the best educator for what works for your bees in your location specifically. I figure if I can keep MOST of the stupid squirrels out, it should be easier for the bees to kick out the few that make it inside. Too bad they don't bite through their shells before they discard their lifeless husks outside the hives...
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