Cellophane bee tunnels resemble ant hills, but the hole is larger, about the diameter of a pencil. Here a bee is seen exiting her excavation; a 2 5/8th-in. lip balm tube was used for scale.
Good Natured: Cellophane Bees
April 14, 2023
The other day I was at Delnor Woods Park in St. Charles, setting out interpretive signs that help acquaint people with the woodland wildflowers (a.k.a. spring ephemerals) now poking up through the leaf litter there–and pretty much everywhere oaks and other natives grow.
Each year, cued by the longer days-and rains-that spring brings, these old friends once again return. Seeing them puts my brain through a few mental gymnastics as I struggle to remember the descriptive scientific binomials that accompany each plant’s common name. Bloodroot…Sanguinaria canadensis…sanguin is Latin for blood…aria, means pertaining to…together they refer to the reddish fluid found throughout the root, stems and leaf veins. Canadensis…where the plant was first collected.
Dutchman’s breeches (which really do look like bloomers hanging on a line)…Dicentra cucullaria…Latin for two-spurred, hood-shaped flowers. And spring beauty (which truly is)…Claytonia virginica…in honor of early botanist John Clayton.
It was there, amongst the beauties, that I realized I wasn’t alone in this reverie. A tiny blur of motion caught my eye. Then came another, and another…
Sorry, woodland wildflowers, you’ll have to wait. Little bits of nature were flying through the air, and I was bound by the Nature Nerd’s creed to investigate.
Walking across the grass by the playground, I soon saw the source of those flying bits. Dozens of small mounds that could easily be mistaken for anthills dotted the lawn area. But rather than ants, each hill was home to yet another old friend-the Colletes, or cellophane, bee.
Colletes comes from the Latin collectus and refers to how the bees’ individual nests are usually found close together–a function of soil conditions, not social ties. Together they formed a good-sized subdivision there in the soil.
Like some human housing complexes, the mounds all looked pretty much the same to me–sandy crumbles of earth with a hole about the circumference of a pencil smack-dab in the center. But somehow the bees knew which burrow belonged to whom. I chose one hole to focus on and after about 5 minutes a bee landed and then quickly disappeared underground. A few minutes later she reappeared and took off again, likely heading for the woods and the spring wildflowers it offers.
Even though they share the same last name of “bee,” cellophane bees (a.k.a. plasterer bees or polyester bees, a reference to the material with which they coat their tunnels) are as different as can be from that pollinator poster child the honey bee. For one, “cellophane bee” isn’t a distinct species but rather a genus of about 100 North American species (perhaps 700 worldwide). Honey bees, which are not native, belong to the genus Apis (which is Latin for “bee”) and the species we see in our area is mellifera (Greek for “bearer of honey”).
Further, honey bees nest above ground, live in colonies with intricate social interactions and store food in the form of, yes, honey.
Cellophane bees live below ground and, while their holes might look as though they all belong to a larger underground colony, their behavior is solitary. The burrows do not interconnect, and each bee is responsible for her offspring only. She provisions each egg she lays with pollen and nectar and that, as they say is the end of that. No meticulous feeding of larvae, a la honey bees, nor bowing to the rulings of a queen.
Also unlike honey bee colonies, which perpetuate from year to year, the cellophane bee’s life cycle is annual, or one-and-done. The eggs that are being laid right now will hatch into larvae, which will then feed, pupate and emerge as adults next spring to start the next generation. The bees we see flying around today will be gone in a few weeks, their brief mature stage over and done with.
Thank goodness though for this final, industrious phase. This early in the year, pollinators that fly are few and far between. Those old friends that lured me to the woods last week–the spring ephemerals–depend on cellophane bees, as well as certain other species, to stop by for a meal of pollen and maybe nectar. As they feed they move pollen grains from flower to flower, ensuring pollination and the development of seeds for the plants’ next generation too.
(Fun fact: The word pollen is from the Latin pollen, which means mill dust or fine flour, and is related to the Latin polenta, “crushed grain” as well as the Greek poltos “pap, porridge,” and Sanskrit pálalam “ground seeds.”)
Next week: We’ll get reacquainted with more old friends as we explore other families of ground bees and the important work they do.
Pam Otto is the outreach ambassador for the St. Charles Park District. She can be reached at email@example.com.