Yesterday I learnt a few things about keeping Mason Bees. I really should have done more thorough research before – now I’m unfortunately learning from my mistakes.
- Our basement is not a suitable winter storage for the cocoons. It’s too warm. I found 6 bees that had already hatched and then starved.
You need to store them around 40F. You can put them in the fridge in October and leave them there until it’s time for them to hatch in March.
- Solid plastic tubes are bad. You can’t extract the cocoons from them. You need to do so in order to check for disease and parasites. In particular, chalk brood (a fungal disease) can quickly spread and kill an entire bee colony.
This season I’m using a wood block with paper inserts, and a segmented plastic block system. Both of these allow you to easily harvest the healthy cocoons and store them safely until the next spring.
It looks like I still have a fair number of healthy cocoons. The trees are finally starting to bloom, so hopefully they will hatch without any further mishap and continue expanding the colony.