Thanks to all of our bee hosts this year, we have had a lot of mason bee cocoons to clean this year.
To make sure that our mason bees are healthy, we clean each cocoon and each nesting block during the fall. We make sure that our bees are clean of mites, parasitic wasps, and chalkbrood fungus which are detrimental to their development. This is a crucial part in taking care of mason bees as these threats can be easily spread to local bee populations if not properly eradicated. We’ve documented parts of the process to share what happens to the bees after they leave your backyard.
Since June, our warehouse has been filled to the ceiling with stacks of mason bee blocks. They spent the summer developing from eggs, to larvae, to fully formed bees in cocoon. The first step is to cut the plastic straps on the blocks to separate the individual pieces of wood and the rows of mason bee cocoons.
We use the tool pictured above to scrape the bees out of the blocks (they are very tough once in cocoon). After some of the initial debris has been sifted out, we soak the cocoons in water and bleach to remove the mites and the chalkbrood fungus.
After they have soaked, we rinse off the remaining dirt and mites. Then we put the bees on racks and dry them overnight.
Finally, the clean bees are candled over a light so that we can pick out the nonviable cocoons. After they are weighed and counted, we store them in our walk-in refrigerator to hibernate for the winter.