Sweat Bee Life

From the archives (upstate New York):

This summer I stumbled upon a sweat bee nest while moving some old boards. The nest was between two boards and this is what it looked like when I lifted the top one off. (Sweat bees, family Halictidae, are often metallic, shiny green or blue.)

Sweat bees vary from solitary to social. This nest had multiple adults, which probably indicates they were living socially. Does anyone recognize the species?

All life stages were present. In this cell there is a ball of food and what looks like an egg (it seems to have a knob at one end?). Usually the food is a mixture of pollen and nectar, hence the yellow-orange color.  See the water beads in the cell? The sweat bees line the cells with wax.

The older larvae are plump grubs. Prior to pupating, the larvae enter a resting stage called a prepupa.

Sweat bee pupae look like most bee pupae. You can see their eyes, mouthparts and antennae. This species does not appear to spin a cocoon.

Everything is pretty neat and tidy.

I tried to replace the board, but when I checked the next day, it was obvious the disturbance was too much. Many of the cells were empty.

The nest was overrun with snails (I think they ate the larval food),

millipedes, sowbugs,

and of course, ants.

What a difference a day makes in the life of a sweat bee.