By Molly Schafer
Did you know there are around 4,000 species of native bees in North America? Surprisingly, this number does not include the honeybee, a non-native which arrived via European colonists around 1620.
Most Americans are familiar with honeybees. From breakfast foods to children’s literature; honey bees are popular characters. Native bees, which are often small, solitary, and non-stinging, are less recognizable. In fact, not much is known about native bees. An estimated 10 percent have not even been named or described by scientists yet.
A majority of native bees are generalists, feeding on a wide variety of flowering plants. Twenty to 45 percent of native bees are pollen specialists, requiring specific plants to survive. We can support these native specialists by planting their host plants, just as we plant milkweed to support monarch butterflies.
To learn more about native bees and their native host plants Mt. Cuba partnered with Matthew J. Sarver of Sarver Ecological on The Mt. Cuba Native Bee Survey. This 2018-2019 survey tracked which bee species are attracted to which native plants at Mt. Cuba, in both the gardens and natural lands.
In the executive summary of the survey report, Sarver states “Due to the diverse and special nature of Mt. Cuba, as well as the fact that Delaware has generally been under-sampled for bees, this project represents one of the most important bodies of information ever compiled for Delaware’s bees.”
A highlight of the survey was the discovery of 15 bee species not previously known to occur in Delaware, resulting in 15 new state records! This is why Mt. Cuba is proud to tout that “if you plant it, they will come.”
Keep reading to meet five of the more than 135 bee species documented at Mt. Cuba.
Read the full report of the Native Bee Survey at mtcubacenter.org/native-bee-survey/
- Augochlora pura
Common in Eastern North America, Augochlora pura was one of the most abundant bees surveyed at Mt. Cuba. The species is named for its striking appearance; Augochlora pura translates to “pure golden green.” Their metallic coloration can range from bright green to a more copper tone or a deep, almost blue-green. Augochlora pura are generalists visiting a wide variety of plants. In early spring they seek out the tiny flowers on maple trees. As the season progresses they feast on flowers in the daisy family (asters, goldenrods and coreopsis), milkweeds, hydrangeas, spiderwort, and many others. This is an important species to leave dead and dying trees around for. Augochlora pura nest under the loose bark of old or fallen trees.
- Summer Cellophane Bee, Colletes aestivalis
The summer cellophane bee is a species of high conservation concern. The only known population in the northeast can be found at Mt. Cuba! In the gardens, look for them along the Woods Path.These bees are specialists feeding on heuchera, also known as coral bells or American alumroot. Many heuchera hybrids are commercially available but it is the wild species Heuchera americana that attracts the summer cellophane bee. Cellophane bees, also known as plasterer bees, secrete a cellophane-like film, which they use to line their nests.
- Carpenter-mimic Leafcutter Bee, Megachile xylocopoidesIn Mt. Cuba’s meadow garden a single carpenter-mimic leafcutter bee was found on yellow thistle (Cirsium horridulum). This bee is a pollen specialist on plants in the Asteraceae genus, one of the largest plant families.Male carpenter-mimic leafcutters have a smooth black abdomen and yellow hairs. Females are all black with fewer hairs than males. They appear similar to a carpenter bee, although they are smaller in size. Female leafcutter bees cut round pieces out of leaves and petals which they use to line their nests. Nests are made of separate chambers or cells stacked one atop each other inside of a narrow cavity. A single egg and a supply of pollen are deposited into each nursery cell before being sealed with a leaf cutting.
- Spring Beauty Miner Bee, Andrena erigeniaeThe spring beauty miner bee is a specialist feeding almost exclusively on the soft-pink pollen of Virginia spring-beauty, a flowering plant in the genus Claytonia. Although spring beauty is a common woodland flower, it must now compete with invasive lesser celandine.Miner bees are ground-nesters, they create holes in the ground or utilizing existing ones. These solitary bees often nest in aggregations, with many individual nests neighboring one another over a small area. In each nest, a female bee lays a single egg on top of a ball of pollen, food for the larva when it emerges. These non-aggressive bees were among the top ten most common bees in the Mt. Cuba survey.
- Three-knotted Long-horned Bee, Melissodes trinodisThe three-knotted long-horned bee visits flowers in the Asteraceae family (asters, daisies), also known as composite flowers. This long-horned species appears to have a preference for sunflowers (genus Helianthus). Native sunflowers are incredibly important for native bee diversity. The Native Bee Survey suggests H. divaricatus and H. decapetalus as appropriate species for the Northern Piedmont region.Long-horned bees are named for the unusually long antennae of the males. In addition to lengthy antennae, male three-knotted long-horned bees have green eyes. Females have thick pollen-carrying hairs on their hind legs and gray-blue eyes.
For more information on native bees, check out Mt. Cuba’s Native Bee Survey.