[shinbone]

These native bees are all over the Butterfly Bush in my yard. There are many more of them than the bees from my hives 50' away. They are just slightly bigger than a honey bee. Anyone know what they are?

 

[Greenride]

Bumble bees, I don't know the variety. We have the same stripe pattern in Boulder(near Niwot) these small ones are the workers. earlier in the season we had larger ones, queens I'm guessing, working the hairy vetch cover crop in our garden. Queens do all the work in the early season till their first brood hatches. Only the queens live through the winter.
Fabian

 

[loghousebees]

It looks like Bombus ternarius , a orange banded bumble bee that has a similar social structure to the honey bee.

 

[iluvicecream]

I've seen these in Denver too!

 

[tabby]

It could be Hunt's Bumble Bee, which are common in Colorado. There's lots of them in my yard.

 

[CS Bee Man]

It is a Rocky Mountain bumble bee. I seen a lot of these this year.