How Bee Hotels Support Urban Pollinators and Educate Locals on One College Campus
By Jacquelyn Fitzgerald
The United States is home to more than 4,000 species of bees. While cities and suburbs support a wide array of pollinators, urban bees face many challenges. Along with increasing pesticide use and dwindling food supplies, loss of habitat has led to declining populations across the country. Available nesting space is at a premium. Luckily, many urban bees are happy to use other accommodations.
Unlike honey bees, most native bees are solitary and do not nest in colonies. About 30 percent of native bees in the U.S. are solitary cavity-nesters. These include the industrious mason bee and flashy sweat bee, among others. For these bees, every female is on her own. Having spent the first 11 months of her life developing from egg to pupa to larva and, finally, to an adult, each bee spends her remaining few weeks entirely focused on reproduction. She will need to build her own nest, without the help of worker bees, and supply her eggs with the food and shelter they will need to survive into the next season.
To make a nest, a female bee must first find a tunnel. A hollow plant stem or an abandoned hole left by a wood-boring beetle will do. Inside this tunnel, she will make a series of rooms, called “cells,” to house her eggs. Each cell will contain a single egg, provisioned with a mixture of pollen and nectar called “bee bread.” In between cells, the female bee will build a partitioning wall. Depending on the species, the wall may be built from materials like leaves, petals, or mud. Soon, the mother bee will die. Her eggs will mature over the winter and emerge as adults, ready to start the cycle over again.
When hollow twigs and old stems are raked up and snaggly beetle-bored wood put away, cavity-nesting bees are left scrambling. Artificial nests, called bee hotels or bee boxes, can help provide nesting materials for native bees. Made from bundles of plant stems or holes drilled in blocks of wood, bee hotels come in a variety of sizes and materials. Many garden stores sell ready-made hotels, similar to bird houses or bat boxes. Others come as do-it-yourself kits. Providing stem bundles of different sizes and lengths will help attract a variety of species across the season.
When constructing a bee hotel, it is important to keep in mind that bee hotels require regular upkeep. Because bee hotels host bees at a higher density than a natural nesting site, disease and pathogens can quickly spread among visitors. Replacing used stems and nest blocks every few seasons can help prevent the spread of mites, fungus, and other parasites.
Besides being refuges for native bees, bee hotels are useful for pollinator education, outreach, and citizen science. There is an enormous diversity of bees across the United States, but many are unaware of bees other than honey bees and bumble bees. Bee hotels can help introduce the public to the amazing array of native pollinators and the services they provide for us.
In Raleigh, North Carolina, the Rebecca E. Irwin lab has installed solitary bee hotels across the NC State University campus. With support from the university’s Sustainability Fund, the lab placed permanent, sheltered bee hotels around campus. Each hotel is accompanied by a sign with information on native bees and the important role they play. Located next to gardens and other green spaces, these bee hotels will help support local bees for many years to come.
Interested in making your own bee hotel? Check out the Xerces Society’s recommendations for instructions:
Jacquelyn Fitzgerald is a research assistant at North Carolina State University in the R.E. Irwin Lab. When not in the lab wrangling bumble bees, you can find her making science videos and illustrations. Email: email@example.com