I recently worked with Louisa and Marckley Ehrlich, high school students at The Academy for Global Studies in Austin, on their capstone project for graduation. They had been hearing about the media coverage of declining bee in the U.S. and were interested in working on that problem.
As European honeybees are a non-native species and potentially dangerous, I steered them toward native solitary bees. One way to help native bees in urban areas is to construct and erect bee nesting blocks. These blocks are used by native solitary bees. These bees do not live in colonies but rather lone female bees do all the work of establishing and provisioning nest sites for their larvae. They are also non-aggressive and do not defend their nest sites so these nesting blocks can be placed in urban and suburban yards with no worries of colony defending worker bees.
Typically, these solitary bees nest in holes in dead trees but those sorts of nest sites can be rare in urban situations. Native solitary bees, like leaf-cutter bees and mason bees, will readily take up residence in nesting blocks. A single female will provision a chamber with pollen and eggs, seal it, and then move on to the next chamber. She does not stick around to provide any additional care to her offspring, hence the lack of desire to defend that nest.
The benefit of placing these nesting blocks in your yard, especially if you are a home gardener, is that native solitary bees are typically much more efficient pollinators than honeybees. In some cases, just over 200 native bees can do the same level of pollination as a hive of honeybees containing over 10,000 workers. Plus, they are safer to have around. Now is the perfect time to build and erect your own bee nesting block.
For details on how to make bee nesting blocks see The Xerces Society’s Nests for Native Bees Fact Sheet
