Mason bees seem to prefer bamboo nests over other nest choices. It’s easy to break open the bamboo nest to clean out infestations of pollen mites. The bees naturally leave a space of almost an inch at the entrance end making it possible to begin breaking apart the bamboo using a cold chisel. Once the cocoons are cleaned up they will be stored in a cool dry place awaiting next spring.

opening bamboo nests

mason cocoons

Notice the yellow cell indicating pollen mites. The larvae in this cell didn’t have a chance with all the pollen mites. Click on pictures to enlarge.

In the first picture there is a Mason bee on a dandelion. You can see the mites clinging to the bee. This is about 60-70 feet from the nest. Some of the literature suggests that carrying the load of mites impedes the flight of the mason bee. It is hard to determine from the literature the full effect of pollen mites on Mason bees. The mites do not effect the bees directly but eat the pollen intended for this years larvae.

In the next picture we are breaking open a mason bee nest to look for infesatations of pollen mites. There were several females still in the nest a few weeks after the first emergance of bees.

In the last two pictures you can see an infestation of mites. When the Mason bees emerge the mites latch on as the bees travel through this mess. Click on the pictures to enlarge.

Now that we have seen that Mason bees prefer bamboo nest tubes over holes in blocks and that the bamboo nests are easy to open we will open the nests at the end of the season and collect and clean the cacoons. Next year we will release the cacoons to a fresh set of bamboo nests.