Mid-February of this year, Terry and I attended a local seed exchange. We had never been to one before so we perused the tables and were welcomed to select and take home any seeds we were interested in, mostly for free. At one table, we stopped to chat with two gals who had small pieces of 2x4 blocks glued together. Many quarter inch holes were drilled into them with a square piece of duroid roofing tile hammered on top. We were told these were orchard mason bee homes. We had never heard of these bees before even though they are quite common in North America.
Orchard mason bees are solitary bees. They do not live in colonies and have a metallic green or blue colouring. At first glance, it is easy to mistake them for a house fly. The mature females are fertile and able to fertilize their own eggs to establish the sex of their offspring. The lifecycle of the mason bee consists of a female finding an appropriate nesting site. They lay their 6 to 8 eggs in long nesting cells. The female (fertilized) eggs are laid deepest in the cell with the male (unfertilized) eggs closer to the entrance of the cell. Each egg is separated by a mud wall and has a food supply of pollen or pollen/nectar for the egg to develop to adulthood. The adult hibernates through the fall and winter and emerges in early spring when the temperature reaches 14 degrees C. The males emerge first and wait for the females to come out. The females mate right away with the males and then the males die. The females feed for several days while waiting for their ovaries to mature and then the work to establish offspring begins once again.
Mason bees transport pollen on the underside of their abdomen as opposed to other bees which collect pollen mostly on their legs. They are considered to be inefficient pollen collectors as they need to take ten times more trips to the flowers of plants to bring back the same amount of pollen collected by honey bees. A mason bee must visit 75 flowers per trip and log 25 trips to stock the food supply for one egg. This inefficiency and committment to hard work is what benefits fruit orchard farmers as mason bees are used to pollinate their trees in springtime.
We bought two mason bee apartments from the seed exchange and placed them under the garage roof overhang. All of the holes are now sealed with mud so we will see what emerges next spring. These bees like staying close to home (no wonder, when you have so much work to do!) so we figure our garden will be the benefactor of their hard work. We are excited to have new residents and hope they are just as happy to be BFF...BEE Friends Forever!