Unknown bees/wasps swarming around flower pot

Hey guys/gals,

New to the forum and need some help identifying some bees/wasps.

I live in Rhode Island, northeast USA close to MA and CT. It's springtime now, and today i was planting some flowers for my Aunt when i noticed what i thought to be a swarm of Black Flies (often incorrectly referred to as "May Flies") swarming around one particular flower pot (approx 3ft in diameter by 2ft deep). The pot hadn't been touched since the fall (before the long horrible snowy winter we had here) and it was full of good compost with some twigs of whatever plant used to be there last year. After turning the soil a bit, the "flies" were getting annoying so i grabbed some ant killer spray and killed them... It was then that i inspected one of them and discovered they weren't Black Flies at all, but some type of bee/wasp.

I didn't take a picture (this was at my Aunt's house) but i got a good look at one. It was approx a half centimeter long (they all were this size) and kind of stubby like a honey bee vs a yellow jacket. It was black in color, not really any colored markings that i remember. I don't think it was hairy.. at least i know its abdomen wasn't. It had a stinger, and kept trying to sting my glove NUMEROUS times- and it was definitely a stinger, not an ovipositor. But i never felt any stings while turning the soil.

I picked up a few and inspected them, all of which had stingers and were all identical in their appearance. They also had pollen on their rear legs similar to bees, but i have a feeling that they're some type of wasp...

I'm not sure if they were being born (from within the dirt) or whether they were laying eggs in it. I'm pretty sure they weren't being born, as when i turned the soil they all disappeared, and if i left for a minute and came back the pot would be swarmed again. And the fact that they had pollen on their rear legs pretty much proves they had been out and had returned for some unknown reason. They were definitely NOT carrying any pray or burying anything at least not of a notable size. I wouldn't say they became "aggressive" when i was turning the soil, they just few away and returned when i left. They were certainly not attacking me.

I ended up removing a good 4" of the top soil and replacing it with new soil (out of the bag) and planted some flowers. But about an hour after the flowers were planted the pot was swarmed again with these bees/wasps, but much fewer of them.

I found it very odd that they were only swarming this one pot, as approx 12ft away was another identical to it. The only difference i can think of between the pots is the amount of sunlight. The pot swarmed with these things was in the shade while the other pot got more sunlight.

Any ideas as to what these things are? I don't have a picture, but i imagine there can't be many bees/wasps of such a small size that would have this sort of swarming behavior around a pot full of dirt. The best way i can describe their movements is to say that they reminded me SO much of Black Flies. They weren't sluggish like honeybees, but weren't exactly "aggressive" like most larger wasps. They were also completely silent even though there had to be at least 100 of them... If you post a picture i'll definitely be able to identify it.

Any help is GREATLY appreciated! Thanks in advance!

Chris

I am gonna have to do the same research because I may be having the same problem you are, except all over my peach tree.
I'll see if i can't get a picture so you can compare XD.

Just a thought...perhaps they are mining bees or wasps and have/had a female laying eggs in the pot.

http://www.uri.edu/ce/factsheets/sheets/miningbees.html

nope mine dont look anything like that. been crazy busy, but will try to post a picture of mine at least later XD.

hmm... i looked up pictures of "Mining Bees" and they're not it... They seem to big (article i found compares size to honey bee) and there weren't any stripes on the abdomen.

I'm going back to my Aunt's tomorrow i'll be sure to grab a few and post pics (if they're still there after all the ant killer i sprayed in the pot).

Love to see a pic. There are black bees. Have you looked at those?