I did feel a bit bananas to be putting bananas in my hive. As a beekeeper for just over five years, I have been hearing for just over five years not to eat bananas before going into the hives because the smell of bananas is very very similar to the alarm pheromone of bees. Twice I have smelled the banana oil alarm and packed everything up and left the bees within moments. The smell is quite distinctive and I am sure that I reeked of my own alarm pheromones at that point as well.
So it was no surprise when a fellow beekeeper suggested I give my hives bananas to help them with the chalkbrood that I thought he was bananas. Nonetheless, I decided to give it a try. This is the top of Sun's hive and since there are LOADS of bees in that hive, they got a whole banana, sliced in quarters atop the frames. The other two hives split a banana.
How did the bees respond to this unorthodox use of fruit? They were very curious. They crawled all over the fruit but didn't act alarmed or fly around.
Why does this work? All my research online and in books suggest this may work by triggering a cleaning behavior in the bees. When they finish with the strange fruit in the hive, they may continue to clean out the infected brood. Honestly no one really knows and no scientists have tracked it either. The state bee inspector was very curious and agreed to recheck the hives later this summer.
Can this lead to some scientific proof? No, for two reasons. First I treated all three hives so there is no control.
Second, I also removed the mouse guards from the two hives that still had them in place - so I also increased the ventilation. Serendipity's hive only has a partial entrance reducer so I left that on for now. I wanted to make it as easy as possible for the bees to remove the infected larvae.
Time will tell.