The pvc tubes hold the cocoons you get from the bee keeper.
The bee keeper "loans" you the cocoons and the empty hive setup. You keep the tubes in the fridge until the temperature get's above 57 F. You then set the tubes out and the males will 'hatch' and wait for the females.
Your garden gets pollinated and the bee keeper gets a new crop of bees- which he sells to nurseries.
The funny thing is, I started to notice wild Mason bees nesting around the house a few years ago. I had never seen green metallic bees before-- thank God for the Internet.