Try adding a tunnel to the entrance as per the dartington, the longer entrance will give the bees more distance and time to defend, and it may key in more to their defensive behaviours, since trees dont usual have only 18mm between the outside and the interior cavitiy of the nest, but more like 150mm
I found out how to keep the bulk of the jaspers away from the hives!
Today was the first day of apple pressing this year 200ft away from the hives, it was a true jasper fest they had juice swimming competitions apple pulp diving people bugging competitions and swatter dodging! either their army was diminishing bigtime or they gave up the onslaught toward the end, 12.5 gallons with a little wasp venom and wings! but a filter and fermentation will sort that out, thursday will be the apple juice for drinking fresh and preserved, should be less jasper carnage by then I hope!!!.