Last week small, sandy nests began popping up on the grounds of our administrative offices at Mariandale. They caught the eye of Karalyn Lamb, a local naturalist on a bird walk, who paused and snapped the above photo of a ground nesting bee emerging from her nest. Then she uploaded the photo to a website which confirmed her intuition — she was looking at an unusually large aggregation of unequal cellophane bees (colletes inaequalis). “It’s very, very unusual to see such a big aggregation,” Karalyn said, “and it’s because this is a protected place.”

Cellophane bees are one of the “miracles of spring” Karalyn said, and they’re important pollinators of early-flowering bushes and trees, including apple trees. The female secretes a waterproof substance which she uses to line her nest and protect her eggs. They spend four to six weeks above ground each year, nesting on sandy, southwest facing land and gathering pollen and nectar. The solitary females build their nests in close proximity to one another, emerging to sun themselves and guard their eggs.

We’ve protected the site with caution tape and have designed yard signs to educate the public. At last count there were around 100 nests!

Cellophane bees are docile and do not sting. If you see the nests in your own yard, you should take steps to protect the aggregation, Karalyn said, and record your sighting on iNaturalist.

The bees return underground at the end of April. Planting early-blooming flowers such as crocus and early-blooming native trees and shrubs such as dogwood and red maple is another way to support the population.

Listen in on our conversation with Karalyn:

For more information about cellophane bees, click this link or watch this 3.5-min video:

Let us know if you spot any ground-nesting bees by leaving a comment below!