Mason Bee cocoon humidity cooler. Pads for water one one side and a place for the cocoons on the other side of the divide.
Besides simply setting cocoons outside in a predator proof box of some kind, cocoons can also be stored in the fridge. Cocoons can be kept dormant until just before bloom. It ensures that bees emerge when flowers are in bloom. This method is most easily done in a humidity cooler. The double compartment is for water on one side and cleaned cocoons on the other side. Fridge temperature is set for 2-4C . Water creates humidity ensuring that cocoons don’t dry out and kill the bee inside the cocoon.