One thing we gardeners should make ourselves more aware of is the difference between yellow jackets, an aggressive ground nesting wasp, and soil nesting bees. We want to have our gentle native bees, who are excellent pollinators, healthy and happy in our gardens. But what is the difference between a yellow jacket wasp and a ground nesting bee?
There are many species of ground nesting bees in North America. They are gentle, mostly solitary bees (rarely live in groups), and only sting if you smack them. We have native ground nesting bees who specialize in squash pollination, and there are ground nesting bees who pollinate our tomatoes and blueberries more efficiently than honey bees. All we have to do to encourage their excellent services is a.) give them a little room to nest in (they are tiny and don’t take up much space) and b.) don’t poison them!
Here is a link to a video I took of a very large yellow jacket colony in an Atlanta Park:
Yellow jackets are predatory wasps, and an important member of the checks and balances that exists in nature’s food web. Without predatory wasps, we would be over run with devastating insect damage to every living plant on the planet. But they are aggressive, so none of us wants a huge yellow jacket nest near our house. More info at this wikipedia link: https://en.wikipedia.org/wiki/Eastern_yellowjacket
For comparison, here are a couple of ground nesting bee nest entrances on the website Bugguide:
http://bugguide.net/node/view/668896
http://bugguide.net/node/view/178216
And here is a Wikipedia article on the ground nesting bee family:
https://en.wikipedia.org/wiki/Halictinae
In the photos of the bee nests, notice how there is one teensy hole, about 3/8’s of an inch across? With one little bee head peering out? She is guarding her eggs, her babies. It’s actually very touching. The ground dwelling bee won’t come out and lance you all over with horrid stinging welts if you are mowing your grass. She is just going to mind her own business. Give her some respect and some space, she’ll give you tomatoes and squash in return. Not a bad deal, eh?