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Solitary Bees

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There are an estimated 20,000 species of bees worldwide, and 90% of those species are solitary. This category of bee does not live in a communal hive. Instead, the female of the species builds her own nest in which to lay and provide for her offspring. Without a hive to protect, the solitary bee is much gentler than the honey bee and sting only if handled. Many are highly efficient pollinators, visiting more flowers per minute than honey bees.

Sections

Mason

Mason bees (Osmia spp.) are gentle, solitary pollinators named for the mud walls they use to divide their nests. They nest in hollow stems, beetle burrows, or bee hotels, and some even decorate their nests with flower petals or use abandoned snail shells. Highly efficient in early spring, a few hundred mason bees can pollinate fruit orchards as effectively as thousands of honey bees. After laying eggs and sealing the nest, the next generation develops through summer and overwinters as pupas until emerging the following spring.

Leafcutting

Leafcutter bees (Megachile spp.) are solitary bees known for cutting neat circles from leaves or petals to construct their nests, usually in hollow stems, rotting wood, or other cavities. Unlike honey bees, leafcutters carry pollen on the underside of their abdomens, which makes them exceptionally efficient pollinators of wildflowers, fruits, vegetables, and crops. They are gentle and non-aggressive, rarely stinging unless handled. One species in particular, the alfalfa leafcutter bee (Megachile rotundata), is widely managed in the northern Great Plains, where it revolutionized alfalfa seed production and continues to play a vital role in commercial agriculture.

Sweat

Sweat bees (family Halictidae) are one of the most diverse and abundant groups of bees in the world, with hundreds of species found across North America. They get their common name from their occasional attraction to human perspiration as a source of moisture and salt, though most spend their time visiting flowers. While many sweat bees are tiny and dark-colored, others shimmer in brilliant metallic greens, blues, or even purples, making them surprisingly colorful for such small insects. Most species nest in the ground, digging tunnels in bare soil or sandy areas, while some prefer rotting wood or plant stems. Because they have relatively short tongues, sweat bees specialize on flowers with accessible nectar and pollen, such as asters, sunflowers, and coneflowers.

Carpenter

Carpenter bees (Xylocopa spp. and Ceratina spp.) are large, sturdy bees that excavate tunnels in dead wood, structural timbers, or hollow plant stems using their strong jaws. Although they are classified as solitary, many species build nests close together, creating loose “neighborhoods.” In these clusters, females sometimes share responsibilities, with some foraging for pollen while others guard nest entrances. Carpenter bees are easy to recognize by their size and shiny, often black abdomens, which distinguish them from the fuzzier bumble bees.