The Digger Bees of the Pacific Northwest
One interesting group of native bees are the digger bees, or ground nesting bees.These bees build nests in the ground, solitary nests. They will lay their eggs and raise their young in these soil tunnels. The sites in any given area that are optimal for these nests are limited and sometimes, hundreds of bees will nest in the same spot, this gives it a look like its a colony, but it is not, each bee has its own nest.
In these areas, each female works to dig out the nest cells and to collect pollen for her young, often next door to many others, However, digger bees do not have any sort of social community and do not form into any sort of social colonies.
The digger bees are not very aggressive and will not sting unless handled roughly. Even then, their sting is much milder than say that of a honey bee or yellow jacket. The male bees cannot sting at all.
One generation per year occurs with the typical digger bees found on Vancouver Island. Winter is spent as maturing larvae within an underground cell. They pupate in late spring and emerge in the early summer. Last summer I found a large nesting area where l did observe hundreds of bees digging their nests, l will be looking to get video this coming summer. The first order for the females will be building a nest, which usually consists of a central chamber extending a few inches below ground and a series of cells spanning out from this chamber. After each cell is complete, the female bees collect pollen which they pack into the chamber and then lay an egg and seal it up. Individual bees live up to 4 weeks which is enough time to build her nest, lay her eggs and seal up the nest.
The males usually fly over the nests during the day looking for females to mate with, (their only job). At night the males move away from the nests and will roost together in bushes and trees.
These bees are prolific pollinators and before the Europeans brought the honey bees, they were one of the main pollinators. With the problems that the honey bees are going through right now, l for one am glad they are still at work doing what digger bees do.