Though honeybees get all the credit, native pollen bees do the bulk of the pollination chores in many gardens, parks, and forests. Pollen bees are also called solitary bees; unlike the highly social honeybees, nearly all pollen bees live solitary lives.
Native pollen bees work more efficiently than honeybees at pollinating flowers. They don't travel far, and so focus their pollination efforts on fewer plants. Native bees fly quickly, visiting more plants in a shorter amount of time. Both males and females pollinate flowers, and native bees begin earlier in spring than honeybees.
Bumblebees (Bombus spp.) are probably the most widely recognized of our native pollen bees. They're also among the hardest working pollinators in the garden. As generalist bees, bumblebees will forage on a wide variety of plants, pollinating everything from peppers to potatoes.
Bumblebees fall within the 5% of pollen bees that are eusocial; a female queen and her daughter workers live together, communicating with and caring for one another. Their colonies survive only from spring until fall, when all but a mated queen will die.
Bumblebees nest underground, usually in abandoned rodent nests. They love to forage on clover, which many homeowners consider a weed. Give the bumblebees a chance – leave the clover in your lawn.
Though often considered pests by homeowners, carpenter bees (Xylocopa spp.) do more than burrow into decks and porches. They're quite good at pollinating many of the crops in your garden. They rarely do serious structural damage to the wood in which they nest.
Carpenter bees are quite large, usually with a metallic luster. They require warm air temperatures (70º F or higher) before they start foraging in spring. Males are stingless; females can, but rarely do, sting.
Carpenter bees have a tendency to cheat. They sometimes tear a hole into the base of the flower to access the nectary, and so don't come into contact with any pollen. Still, these native pollen bees are worth encouraging in your garden.
3. Sweat Bees
Sweat bees (family Halictidae) also make their living off pollen and nectar. These small native bees are easy to miss, but if you take the time to look for them, you'll find they're quite common. Sweat bees are generalist feeders, foraging on a range of host plants.
Most sweat bees are dark brown or black, but the blue-green sweat bees bear pretty, metallic colors. These usually solitary bees burrow in the soil.
Sweat bees like to lick salt from sweaty skin, and will sometimes land on you. They're not aggressive, so don't worry about getting stung.
4. Mason Bees
Like tiny mason workers, mason bees (Osmia spp.) build their nests using pebbles and mud. These native bees look for existing holes in wood rather than excavate their own. Mason bees will readily nest in artificial nest sites made by bundling straws or drilling holes in a block of wood.
Just a few hundred mason bees can do the same work as tens of thousands of honeybees. Mason bees are known for pollinating fruit crops, almonds, blueberries, and apples among their favorites.
Mason bees are slightly smaller than honeybees. They're fairly fuzzy little bees with blue or green metallic coloring. Mason bees do well in urban areas.
5. Polyester Bees
Though solitary, polyester bees (family Colletidae) sometimes nest in large aggregations of many individuals. Polyester or plasterer bees forage on a wide range of flowers. They're fairly large bees that burrow in the soil.
Polyester bees are so called because females can produce a natural polymer from glands in their abdomens. The female polyester bee will construct a polymer bag for each egg, filling it with sweet food stores for the larva when it hatches. Her young are well-protected in their plastic bubbles as they develop in the soil.
6. Squash Bees
If you've got squash, pumpkins, or gourds in your garden, look for squash bees (Peponapis pruinosa) to pollinate your plants and help them set fruit. These pollen bees begin foraging just after sunrise, since cucurbit flowers close in the afternoon sun. Squash bees are specialized foragers, relying only on cucurbit plants for pollen and nectar.
Solitary squash bees nest underground, and require well-drained areas in which to burrow. Adults live just a few months, from mid to late summer when the squash plants are in flower.
7. Dwarf Carpenter Bees
At just 8 mm in length, dwarf carpenter bees (Ceratina spp.) are easy to overlook. Don't be fooled by their small size, though, because these native bees know how to work the flowers of raspberry, goldenrod, and other plants.
Females chew an overwintering burrow into the stem of a pithy plant or old vine. In spring, they expand their burrows to make room for their brood. These solitary bees forage from spring to fall, but won't fly very far to find food.
8. Leafcutter Bees
Like mason bees, leafcutter bees (Megachile spp.) nest in tube-shaped cavities and will use artificial nests. They line their nests with carefully sheared pieces of leaves, sometimes from specific host plants – thus the name, leafcutter bees.
The leafcutter bees forage mostly on legumes. They're highly efficient pollinators, working flowers in mid-summer. Leafcutter bees are about the same size as honeybees. They rarely sting, and when they do, it's quite mild.
9. Alkali Bees
The alkali bee earned its reputation as a pollinating powerhouse when alfalfa growers started using it commercially. These small bees belong to the same family (Halictidae) as sweat bees. They're quite pretty, with yellow, green, and blue bands encircling black abdomens.
Alkali bees nest in moist, alkaline soils (thus their name). They live in arid regions west of the Rocky Mountains. Though they prefer alfalfa when its available, alkali bees will fly up to 5 miles for pollen and nectar from onions, clover, mint, and a few other wild plants.
10. Digger Bees
Digger bees (family Adrenidae), aka mining bees, are widespread and numerous, with over 1,200 species found in North America. These medium-sized bees begin foraging at the first signs of spring. While some species are generalists, others form close foraging associations with certain types of plants.
Digger bees, as you might suspect by their names, dig burrows in the ground. They often camouflage the entrance to their nest with leaf litter or grass. The female secretes a waterproof substance, which she uses to line and protect her brood cells.
- Alternative Pollinators: Native Bees, Lane Greer, NCAT Agriculture Specialist, 1999.
- Kaufman Field Guide to Insects of North America, Eric R. Eaton and Kenn Kaufman, 2007.
- Native Bee Benefits, joint publication of Bryn Mawr College and Rutgers University, May 2009.