The Buzz Around Our Native Bees
Bees. These remarkable bugs are more than just fuzzy visitors to flowers or “scary” insects that sting. They are vital pollinators who play a crucial role in maintaining the health of our mountain ecosystems and the planet as a whole.
When most people think of bees, they picture the classic honey bee: living in its bustling hive, making honey, and serving the queen. However, honey bees are not native to North America and their highly social lifestyle represents only a small fraction of the world’s bee species.
In fact, the vast majority of bees around the world and in the Sierra Nevada are solitary, up to 85% living quiet, independent lives that often go unnoticed by humans. In these species there are no queens, no workers, and no hives.
Rather, every female bee is essentially a one-bee construction crew, food gatherer, and parent all rolled into one. After snowmelt, they find or build suitable nests, collect nectar and pollen, and create a carefully stocked nursery for future offspring. After supplying the nest chamber with food, the female lays a single egg, seals the chamber, and begins the process of preparing the next chamber for another egg. Once her work is complete, her life cycle comes to an end and the next generation develops during the winter months to emerge in the spring.
Meanwhile, male bees have a simpler life. Their lifespan lasts only a few weeks and equates to: emerge, compete to find a mate, reproduce, and that’s about it.
Native Tahoe/Truckee bees come in an incredible variety of shapes, sizes, and colors. Some wear the familiar yellow-and-black striped patterns while others look like tiny flying jewels, shimmering in the sunlight with their metallic greens, blues, or bronze. When identifying whether an insect is a bee, a helpful clue is to look for yellow, dusty pollen clinging to its body. Female bees often carry pollen on specialized hairs attached to their legs called corbiculae (or “pollen pants”), and other species will tote it on the underside of their abdomens.
Tahoe/Truckee Bee Diversity
One of the most interesting solitary bees around Tahoe/Truckee are leafcutter bees (Megachile spp.). These tiny architects carefully cut out near-perfect circles from leaves or other plant material and carry them back to their nests. They then use the leaf pieces to form the structure of their nursery chamber cells, and, like wallpaper, the leaf material lines and protects the chamber to promote growth of beneficial microbes.
Gardeners sometimes notice the neat circular holes left behind by the leafcutters and wonder, “What happened?” Fortunately, it’s most often good news. The holes rarely harm the plant as a whole, and the “damage” is little more than a tiny rental fee, paid in exchange for excellent pollination services.
Mason bees (Osmia spp.) include another type of solitary bee found in our area. These small critters have dark bodies and an often iridescent sheen, and can easily be mistaken for a fly. However, they are all bee: widely considered some of nature’s most efficient pollinators. A single female has been known to pollinate up to 2,000 blossoms in one day.
Her pollinating power comes from how she carries pollen. Instead of packing it tightly on her legs, the mason bee female carries it loosely on the underside of her body, allowing her to transfer more pollen between flowers. Around Tahoe/Truckee you can find mason bees living in natural cavities such as hollow stems and holes in wood, but they will also readily occupy homemade bee boxes with paper or cardboard nesting tubes placed near flowering plants (a fun project for your yard).
For other bees, that patch of exposed dirt in your yard or a downed log out back can be prime real estate too, so leave them be!
Of course, no discussion of Sierra buzzers would be complete without mentioning bumble bees (Bombus spp.). The fuzzy giants of the bee world, bumble bees are larger, louder, and easier to spot than many of their smaller relatives.
Unlike most of the area’s native bees, bumble bees are social insects, forming small colonies led by a single queen and supported by a female workforce. Their colonies, however, function very differently from honey bee hives. As fall approaches, the workers die off, leaving only the newly mated queens alive, seeking shelter underground where they overwinter beneath the snowpack. When spring arrives, each queen emerges to build an entirely new colony from scratch.
Truckee/Tahoe is home to several bumblebee species, including the endangered Western Bumble Bee (Bombus occidentalis). Not long ago, at Sagehen Creek Research Station, Dr. Nina Sokolov of UC Berkeley found 23 Western Bumble Bees in just 45 minutes, a remarkable find given this species is endangered and difficult to find across the state of California. Perhaps Truckee is a hotspot for this species? More research and time will tell, but for now this is encouraging for Bombus occidentalis.
Supporting
the Bees That Support Us
Bees play a critical role in maintaining our region’s biodiversity. Their services support the plants that provide food and shelter for countless other species, while encouraging outcrossing among the plants themselves, increasing genetic diversity and creating stronger, healthier, and more resilient communities of organisms.
Sadly, not all news is good, and our bees face many challenges. Habitat loss, disease, pesticide exposure, and climate change all threaten native bee populations. Habitat loss from human development destroys both nesting sites and the flowering plants bees depend on. Pesticides may directly harm the pollinators or indirectly kill the plants they rely on. Climate change creates timing mismatches between flowers and the bees’ emergence.
Fortunately, communities throughout our nation are recognizing the importance of protecting pollinators, and Truckee has an exciting opportunity to join that effort. The Tahoe Institute for Natural Science (TINS) is leading the charge to designate the Town of Truckee as an official “Bee City.” TINS and other partners through Bee City USA intend to protect native pollinators through education, habitat restoration, and conservation. While the designation is an important milestone, its true value lies in the community actions that follow.
Residents can help in surprisingly simple ways; planting native flowers and leaving patches of bare soil, dead wood, and dried stems all work to create nesting opportunities. Even participating in community science projects using iNaturalist, a free app that helps identify plants and animals while collecting data for science and conservation, can help researchers better understand local bee populations. In this way, every yard, garden, school, neighborhood, and human can become part of the solution.
So, the next time you hear a faint buzz while hiking a trail, walking through a meadow, or tending your garden, take a closer look and try to appreciate the bee for who it is and what it does.
These remarkable insects may be small, but their impact is enormous. Quietly and tirelessly, our native bees sustain the wildflowers, forests, and vibrant landscapes that make the Sierra Nevada the wonderful and biologically diverse place that it is.
