by Karen Lyness LeBlanc
Native bees are not receiving the attention honeybees have been given recently, but they are also experiencing a significant population decline. In places where there is significant natural habitat, native bees may provide all of the pollination needed for some crops. So maintaining habitat for native bees has economic, as well as ecological benefits.
Habitat loss is likely the single largest threat to native bees. Heavily managed landscapes often lack significant nest sites for native bee colonies. Native bees have very different habitat requirements from honeybees. They are generally a solitary species with each female constructing a nest by herself. Native bees are often elusive and only observed for a few weeks a year when adults emerge to seek sustenance and thereby pollinate crops. For the remainder of the year these bees remain hidden from sight in their underground nests.
Approximately, 30% of the 4,000 native bee species are solitary wood-nesters building their homes in the soft pithy centers of branches. Box elder, sumac, dogwood, elderberry, and various cane berries provide good hollow tunnels for nest building. Most native bee species (the other 70%) build their homes underground, burrowing two to thirty-six inches under the surface.
How to Support Native Bees
Here are some ways you can support native bees:
- Keep dead or dying trees and branches whenever safe. Wood boring beetles often have created narrow tunnels into which solitary bees will make their home. Rotting logs also provide nest sites for some bees.
- Protect sloped or well-drained ground sites where bees can find direct access to soil. These areas are prime nesting spots for ground bees.
- On farms or open lands, keep some areas untilled. Turning over the soil will destroy ground nests that are present and will prevent the emergence of bees nesting deeper in the soil.
To create sites for tunnel-nesting bees: Use a hand drill with a 3 – 9mm bit and drill holes as deep as possible into downed dry wood, then stand the section upright like a fence post to simulate a beetle-tunneled snag. Varying the diameter of the holes will allow different size bees access. You can also use your drill to create holes in stumps or standing dead wood that is not rotting or saturated with water. Try to angle the holes slightly upward so there is less chance of water entering. Also plant shrubs with pithy centers (e.g., box elder, sumac, dogwood, elderberry, raspberry). Each year cut back some of the new growth to enable access to the inside of the stems.
For ground-nesting bees, avoid turning over the soil, this will maximize ground-nesting sites. Bees need stable soil for nesting because their young will spend up to eleven months of the year underground.
Bumblebees live in the grassy interface between open fields and hedgerows or woods. Mow in late fall or winter after the colonies have died and when the queens are dormant.
Native Plants for Native Bees
Providing the pollen and nectar sources that bees require is important for the health of bee colonies. When bees have easy access to resources they do not use as much energy traveling to and from the nest, which allows them to give more to their offspring. As a result, the bees will reproduce faster and the populations will grow more quickly.
Bees cannot see red. They can see yellow, blue, and other ultraviolet hues and prefer flowers of these colors. Bees do have a powerful sense of smell and usually pollinate flowers with a delicate, sweet scent. The following are lists of native plants that provide important sources of pollen and nectar to bees.
Trees, Shrubs & Vines
Black Chokeberry, Aronia melanocarpa
Buttonbush, Cephalanthus occidentalis
Coral Honeysuckle, Lonicera sempervirens
Dogwood species, Cornus species
Elderberry, Sambucus canadensis
Flowering Raspberry, Rubus odoratus
Highbush Blueberry, Vaccimum corymbosum
Lowbush Blueberry, Vaccimum angustifolium
Pussy Willow, Salix discolor
Red Chokeberry, Aronia arbutifolia
Rosebay Rhododendron, Rhododendron maximum
Shadbush, Amalanchier canadensis
Staghorn Sumac, Rhus typhina
Summer Sweet, Clethra alnifolia
Wild Clematis, Clematis virginiana
Asters (various species)
Black-eyed Susan, Rudbeckia hirta
Blazing Star, Liatris spicata
Blue Vervain, Verbena hastata
Cranesbill, Geranium maculatum
Foxglove Beardtongue, Penstemon digitalis
Great Blue Lobelia, Lobelia siphilitica
Purple Butterflyweed, Asclepias incarnata
Purple Coneflower, Echinacea purpurea
Purple Joe-Pye, Eupatorium purpureum
Showy Goldenrod, Solidago speciosa
Sundial Lupine, Lupinus perennis
Wild Bee Balm, Monarda fistulosa
Wild Stonecrop, Sedum ternatum
Woodland Sunflower, Helianthus divaricatus
Wreath Goldenrod, Solidago caesia
About the Author
Karen Lyness LeBlanc is Education and Outreach Coordinator for Project Native. Karen came to Project Native in 2005 with a degree in Environmental Education and Cultural Studies. Project Native is a non-profit native plant farm, nursery and wildlife sanctuary in Housatonic, Massachusetts. You may reach Karen at email@example.com.