26 September 2023

Last week at Duck Hollow I found two bumblebees asleep on goldenrod. The temperature was a little chilly but the morning was bright and sunny. Were the bees waiting to warm up in the sun?

Eight weeks ago I highlighted the reason why male bees sleep on flowers in July and August. Males don’t live in a hive so they sleep outdoors. They are solitary, searching for a mate, and nearing the end of their lives.

Female bumblebees return to the hive at night if they can. In the hot months of July and August females are indoors at night. However bad weather or chilly temperatures may force them to sleep outdoors until they warm up the next morning.

So I wondered are these sleeping bumblebees male or female? I can tell with a closer look at the bees.

Female bumblebees bring food to the hive so they have pollen sacks on their hind legs. If you see a full pollen sack on a bee’s hind leg you can be sure it’s female, as shown on the right in the photo below.

A bee without pollen, like the one on the left, is either a female who delivered her pollen and has just come back for more, or it’s a male without a pollen sack.

I can see two obvious differences between male and female in these photos.

	Male	Female
Hindlegs	Hairy	Smooth convex-shaped structure for holding pollen. (This one contains pollen!)
Stinger at back end (pink arrow)	No stinger	Has a stinger

There are even more clues than this! Read all the details at Sciencing.com: How to tell if a Bumblebee is male or female.

And finally, were these two near the end of their lives?

Yes, both will die this autumn. Only fertilized queens make it through winter. Every hive starts with a lone queen in the spring.

(photos by Kate St. John)