Personal. observations by G Fletcher and purchase information for mason bees and Phragmites tubes for their culture
Harvesting Mason Bees —
NOTE: I have updated this 2015 post in order to make it appear closer to the other mason bee information
The Mason bee tubes are generally filled and a mud cap can be seen plugging the hole of the tube by the end of April-May and no further activity will be seen. It is best to not disturb the tubes for several weeks as the eggs are delicately placed on the stored food materials in each capsule and they take several weeks to get firmly implanted.
Any time after October you can open the tubes and clean the cocoons of parasites for storage over winter in a refrigerator or a cool place outside protected from mice and birds. Some tubes may appear empty. Use a wire or a small round file to check.
Unused tubes may be used again but only if they are clean and parasite free.