day before.
Once the provision is complete, she backs into the hole and lays an egg on top of it. She collects more mud to seal off the partition. The new wall also doubles as the back wall of the next cell. She continues until she has filled the nest hole. O. lignara, like many insects, can select the gender of the egg they lay by fertilizing the egg, or not. Unfertilized eggs are males, while fertilized eggs are females. The adult bee lays female eggs in the back of the burrow, and the male eggs towards the front. She lays about three males to every nest hole depending on depth.
When the egg hatches, the larva consumes the food provision as it goes through many changes on its way to becoming an adult. It will spend most of its life alone in this dark cell made by its mother.
Once the female has finished the nest, she plugs the entrance with one thick mud wall. Then she seeks out another location for a new nest. She works tirelessly until she dies. An O. lignaria female lives for about four to eight weeks and she can complete an average of four 6-inch tubes in her lifetime, with about eight eggs per tube. That's nearly 60,000 blossom visits per female. Because of this farmers have cultivated the insect for pollination purposes in fruit orchards.
By the early summer, a larva has consumed all of its provisions and begins spinning a cocoon around itself and enters the pupal stage; the adult females die off as the season progresses.
The young bee is now a fully developed insect and diapauses inside its cocoon for the duration of the winter. They burn through their fat reserves to stay warm. If it stays cold for too long, the bees can die of starvation. Alternatively, if the temperature rises too fast, they may emerge before the blossom. Farmers are known to exploit their emergence cycle and time their release to coincide with the first orchard blossoms.
Commercial Availability. Recently, many people have become interested in the blue orchard bee (Osmia lignaria), also called the orchard mason bee, as a garden and orchard pollinator. Many thousands of mason bee nesting blocks are sold each year in the United States, along with hundreds of thousands of blue orchard bees. This interest has greatly raised public awareness about the importance of pollinators; however, it is important to remember that raising large numbers of a single species (bee-ranching) is a different objective than the conservation of diverse species of wild pollinators.
As mason beekeeping has increased in popularity, important questions are being asked about the risks associated with the nationwide shipment of blue orchard bees by commercial producers. In fact, there are two distinct subspecies of the blue orchard bee: Osmia lignaria propinqua in western North America and Osmia lignaria lignaria in the east. The species is rare in the Great Plains region, although some intermediate specimens have been collected.
Most commercial producers of the blue orchard bee are located in the Pacific Northwest, where they rear the locally native western subspecies . Unfortunately, the bees these producers raise are then marketed nationwide, resulting in the frequent shipment of locally non-native bees to the eastern United States. The potential ecological consequences of the western blue orchard bee hybridizing with its eastern subspecies are unknown. Similarly, these shipments have the potential to introduce locally non-native parasites and diseases. For the consumer, there is another significant drawback. The western bees may not develop in sync with local conditions, resulting in poor establishment and poor performance as pollinators. The net result is that people purchasing blue orchard bees over the Internet or through garden catalogs may be doing more to harm their local pollinator populations than to help them – and not be getting the pollination they paid for.
This is a family of bees that are often referred to collectively as plasterer bees, due to the method of smoothing the walls of their nest cells with secretions applied with their mouthparts; these secret