It's the Season for Busy Ground-Nesting Bees!

A bee in the genus Andrena poking its head out of a tunnel it made in the lawn of an urban yard.
A bee in the genus Andrena poking its head out of a tunnel it made in an urban yard.

As the weather warms up, insects and other animals are becoming more active. I wrote the other day about social wasps waking up, but here I'd like to talk about another close relative you may see in abundance right now: native, solitary, ground-nesting bees!

There are many species of native bees in NC (for more information see this wonderful bee guide!).Ground-nesting bees can be found throughout the state and are active during warm parts of the year. However, the most conspicuous activity typically happens in March when dozens to hundreds of bees emerge from the ground after developing as larvae the year before. Small mounds of loose soil pop up, especially in bare patches of ground where the vegetation is not very dense. When really active, numerous bees fly around the area like a giant bee metropolis (beetropolis?). The bees mate, and the industrious females collect pollen to provision cells in the ground where the eggs will be laid.

Numerous holes in the ground from the nests of Andrena mining bees.
Numerous holes in the ground from the nests of Andrena mining bees.

Many people cringe or panic at the mere mention of bees, let alone hundreds of them flying around one's yard. But fear not: these bees are solitary (they nest in a group but do not have a colony to defend) and are not aggressive. They are very reluctant to sting -- in fact for the photos on this page I laid in the aggregation for more than an hour, and the bees simply waited for the annoying giant to leave.

These bees are not only native, but are wonderful pollinators of spring flowers. They are also only active for a few weeks, at which time the adults die out, leaving their larvae to develop underground. Thus we suggest leaving them alone if possible. It can be a safe and wonderful experience seeing these insects out and about, and they are an integral part of our local ecosystem.

If you really must get rid of these bees, this fact sheet will help. The bottom line? Promoting dense vegetation or turf will discourage these bees from nesting in the area (they prefer bare or patchy ground).

But if you can stand them for a few weeks, please let them BEE!!!