We have blogged often lately about solitary bees, wild bees, native bees… non-honeybees. Not to detract from honeybees. They are beloved insects and vital pollinators. They are the super stars of the insect world in many ways and humanity stands to learn much from observing honeybees. They are in the spotlight more than other bee species because many complex issues affect honeybees.
This makes it easy for ‘other’ bees to seem undervalued as they languish in relative obscurity because they are rarely seen as super star pollinators. Perhaps honeybees get stellar status partly because they are ‘one of a kind’ as bees cultivated by humans. In comparison, there are over 20,000 known bee species in the world, and according to the USGS 4,000 species of bees are native to the USA.
Some species of solitary bees are truly pollination superstars. And many face similar problems to those that honeybees face. Solitary bees are important pollinators of many plants and crops that rely on them for pollination. These bees nest in small cavities of decaying wood rather than living in beehives like honeybees. Solitary bees live alone, and do not produce honey or beeswax. A single female creates her own tubular nest, segmented into 5-10 individual cells, and each contains a single egg. Tunnel-nesting bee species nest in tree cavities and ground-nesting species nest in holes in the ground.
This 5:18-minute video by Bee Built has some fantastic footage of solitary bees:
These insects transport pollen and assist in pollination while they go about their own business of foraging for food. Many solitary bees are generalists, as they are adaptable and feed on pollen and nectar from a wide range of plants. This increases their chances of survival in case some plants die out. Some species are specialists, focusing on a small number of plants. A few species are dedicated entirely to a single plant species, which is potentially precarious for plant and bee.
Solitary bees have suffered losses in diversity, abundance, and range because of agricultural intensification, pesticides, parasites, climate change and habitat loss due to urban expansion. Urban ecosystems can be planned to include additional foraging resources close to their nesting sites. Bergamot, goldenrod, black-eyed Susan, purple prairie clover, smooth aster and yellow evening primrose help these bees. Leave some ‘wild patches’ to attract these tiny bugs.
Building a bee house for wild bees helps them with habitat. Simply use a wooden box that is open at one or both sides filled with wooden blocks or little logs with 10 cm deep drilled holes in various diameters from 2-10 millimeters. Remove any sawdust and place the house in sunshine facing east or south. There should be no vegetation in front of the “bee house” and it should be at least 3 feet above ground.
Bee houses require minimal care. If birds attack the tunnels, a piece of chicken wire across the entrance protects the bees. In winter, place the house in a dry, unheated shed or protect the entrances with a piece of plywood or tarp. The overwintering pupae need to be cold but dry all winter. If by summer’s end you still have cells that are “walled-up,” they are dead so remove and destroy them.
Solitary bees might include bumblebees, mason bees and leaf-cutter bees. Building a bee house and providing a bee bath fresh water source benefits the amount of pollination your garden will receive, just by creating a habitat for harmless, non-aggressive solitary bees.
Purchasing commercially made bee houses is not encouraged. Some are fine, but many are expensive and inadequate for bees as they provide insufficient protection from wet weather. The hole sizes in some are too large with splinters inside and no solid back wall, creating open-ended wind tunnels. Some are made of a material which causes condensation and the growth of molds.
If you see solitary bees gracing your garden with their presence, honor them and treat them all as superstar pollinators, or VIPs. These sweet and gentle little insects always leave a place better off than they found it.