What are solitary bees?
This is the first installment in a new series exploring the pollinators that share your garden with honey bees. Each month, we'll profile a different native bee group, covering identification, biology, and habitat.
Why dedicate space to bees that don't make honey?
Because most of us walk past dozens of native bees every day without recognizing them. We see a small insect on a flower and assume it's either a honey bee or "some kind of fly." The reality is far more interesting.
We'll start with solitary bees, the largest category of native pollinators in North America.
How many bee species are there?
There are over 20,000 bee species in the world (Xerces Society). One makes honey and lives in managed hives. The majority of the remaining species are solitary - though some native bees, including bumble bees and stingless bees, are social, and many others fall somewhere on a spectrum between social and solitary behavior.
That single honey-producing species, Apis mellifera, dominates our mental image of what a bee looks like. Fuzzy. Yellow and black striped. Living in a hive with thousands of sisters. Making honey.
Most bees look nothing like that.
Native bees range from metallic blue to jet black to striped patterns that would make a wasp jealous. Some are smaller than a grain of rice. Others are larger than honey bees. They nest either in the ground, in hollow stems, in wood, or even in abandoned snail shells—different species have different preferences. They work alone.
According to researchers at Cornell University, many native bees pollinate two to four times more effectively per flower visit than honey bees. Research from UC Berkeley found that tomato farmers may see 50 percent more fruit, nearly twice the size, when bumble bees visit their crops. This is because bumble bees perform "buzz pollination"—vibrating their flight muscles to shake pollen loose from tomato flowers—something honey bees cannot do.
A 2019 study published in Nature Ecology & Evolution by researchers at Rutgers University found that wild bee diversity, rather than honey bee abundance alone, predicted pollination stability across agricultural landscapes. When native bee populations decline, crop yields suffer even when honey bee colonies are present.
Solitary bee lifecycle and behavior
Every solitary bee female is both worker and queen combined. She establishes her own nest, forages for pollen and nectar, provisions individual brood cells, lays eggs, and seals each chamber.
Dr. Jason Graham, Senior Beekeeping Advisor at Primal Bee, spent his PhD at University of Florida studying tunnel-nesting solitary bees and wasps. "Solitary bees are the single mom of the insect world," he explains. "Each female does everything alone. She builds the nest, collects the pollen, provisions each cell, and lays the eggs. Then she dies before her offspring ever emerge."
No parental care. No learning period. Her offspring inherit their behaviors entirely through instinct. Each new generation works alone from the moment it emerges.
The lifecycle follows a predictable pattern. A female emerges in spring, mates, then spends the rest of her short life (typically 4-6 weeks) building and provisioning nest cells. She collects pollen and nectar, mixing them into a "bee bread" that she deposits at the back of each cell. She lays a single egg on top of this food supply, then seals the cell with mud, leaf pieces, or plant resin depending on her species.
The egg hatches into a larva that consumes the stored food over several weeks. It then pupates and remains dormant through fall and winter, emerging as an adult the following spring to repeat the cycle.
Males typically emerge first, waiting near nest sites to mate with females as they appear.Males typically emerge first, waiting near nest sites to mate with females as they appear. Males often mate with many females over the course of their lives, but they contribute nothing beyond reproduction—they don't help build nests or gather food. They simply feed themselves until they die, usually within a few weeks.
Types of solitary bees in North America
Four main groups of solitary bees are common across North America. Learning to recognize them transforms how you see your garden.
Mason bees (Osmia species) nest in hollow tubes and cavities. They're small, often metallic blue or green, with a compact fuzzy body. In early spring, they're active before honey bee colonies have built up foraging strength. You'll see them working fruit trees while the weather is still too cold for honey bees to fly efficiently.
A single mason bee female makes roughly 1,800 flower visits per egg laid. She provisions 20-30 cells in her lifetime, visiting tens of thousands of flowers in just 4-6 weeks. Mason bees use mud to seal their nest cells, hence the name. They're exceptional orchard pollinators because they work in cooler temperatures and visit more flowers per hour than honey bees.
Leafcutter bees (Megachile species) cut precise semi-circular discs from leaves to construct their nest cells. You've probably seen their handiwork on rose bushes, redbud trees, or other soft-leaved plants. The cuts are remarkably clean and circular, as if made with a hole punch.
Leafcutter bees are similar in size to honey bees and carry pollen on fuzzy abdomens rather than leg baskets. This "belly flopping" pollination style makes them incredibly effective. Alfalfa seed production in the western United States depends almost entirely on managed leafcutter bees because honey bees don't trigger the flower mechanism properly.
Mining bees (Andrena species) excavate ground burrows. Small holes in bare ground surrounded by tiny soil mounds, often mistaken for ant hills. A 6mm bee digging an 18-inch tunnel equals you digging 90 feet by hand.
Mining bees often nest in aggregations. Hundreds of females may dig individual burrows in the same patch of ground, creating what looks like a tiny city. Each female maintains her own nest, though. They're not sharing or cooperating. They simply prefer the same soil conditions: bare, well-drained, often south-facing ground that warms early in spring.
If you see small mounds of soil appearing in your lawn or garden in early spring, look closely. You may spot mining bees coming and going. They're completely docile and rarely sting, even when their nesting area is disturbed.
Carpenter bees tunnel into dead wood. Those large, often metallic bees hovering near your deck or fence posts are likely carpenter bees, not bumble bees. The key difference: carpenter bees have shiny, hairless abdomens, while bumble bees are fuzzy throughout.
Carpenter bees get a bad reputation for drilling into structures, though they strongly prefer unpainted, weathered wood. A fresh coat of paint or stain typically deters them. They're important pollinators of open-faced flowers and are among the few bees capable of "buzz pollination," vibrating their flight muscles at specific frequencies to release pollen from flowers like tomatoes and blueberries.
How to identify native bees in your garden
The iNaturalist app (free, over 300 million observations from 3.3 million users) can help identify bees from photographs. The app uses AI to suggest possible species, then community experts confirm or correct the identification.
For best results, capture multiple angles. A top-down shot showing wing venation and body shape. A side view showing the face and leg structure. A shot of the bee on a flower showing relative size. Good lighting and sharp focus matter more than expensive camera equipment. Most smartphone cameras work fine.
While definitive species-level identification sometimes requires microscopic examination of anatomical features, apps like iNaturalist are increasingly effective at identifying bees from photos - often to family or genus level, and frequently to species. You can quickly learn to recognize major groups, which is enough to appreciate the diversity visiting your garden.
For dedicated tracking, Bumble Bee Watch focuses specifically on bumble bee species and contributes to conservation research. The Great Sunflower Project tracks pollinator activity more broadly and accepts observations of any bee species. In Hawaii, the Pollinators in Paradise project on iNaturalist helps researchers track populations of native pollinators, including the endangered Hawaiian yellow-faced bees — the first bees to be added to the U.S. endangered species list.
The act of photographing and identifying bees changes how you observe your garden. You start noticing details: which flowers attract which bees, what time of day different species are active, where they might be nesting. The garden becomes more interesting when you know who's visiting.
How to create habitat for native bees
The best native bee habitat often comes from what you don't do rather than what you add.
Mining bees need bare ground. If every inch of your yard is mulched, planted, or paved, ground-nesting bees have nowhere to live. Leave a patch of exposed soil, ideally in a sunny, well-drained spot. A few square feet is enough.
Cavity-nesting bees need hollow stems. If you cut back all your dead plant stalks in fall, you're removing potential nest sites. Leave some standing through winter. Pithy-stemmed plants like elderberry, raspberry canes, and cup plants provide excellent nesting opportunities when cut to varying heights.
Leafcutter bees need leaves to cut. Skip the pesticides and let them work. The circular cuts are cosmetic damage only and don't harm plant health.
Carpenter bees need dead wood. That old fence post, fallen branch, or untreated lumber scrap? Leave it. Better they nest there than in your deck.
Research from the Xerces Society shows that commercial "bee hotels" often do more harm than good. Many have tubes of improper diameter, lack adequate cleaning access, and promote disease and parasite transmission between seasons. If you want to provide artificial nesting sites, drill 6-8mm holes in untreated wood blocks and replace them annually. Clean out old tubes each fall. Avoid the elaborate "insect hotels" sold at garden centers.
Native plants provide superior forage. Species native to your region co-evolved with local pollinators over thousands of years. They bloom at the right times, produce the right pollen, and fit the right body shapes. A garden full of native plants supports more bee species than one planted entirely with ornamental hybrids.
Next time you're in the garden, slow down. That small metallic bee on your rosemary isn't a honey bee. The circular cuts in your rose leaves aren't pest damage. The tiny holes in bare ground near your fence aren't ant hills.
Once you start noticing, you'll see them everywhere.
