Subject: green bee
Location: Denver CO
June 8, 2014 12:17 pm
There has appeared in my buffalo grass lawn several dirt mounds that at first seem to be larger steep ant hills, but today I saw these colorful bees going in and out. Are they natives?
Signature: Jeanette

Metallic Sweat Bee

Metallic Sweat Bees

Hi Jeanette,
These beautiful, little, native bees are known as Metallic Sweat Bees, most likely in the genus
Agapostemon, based on images posted to BugGuide.  Of the subfamily Halictinae, BugGuide notes:  “Most species nest in burrows in banks or in the ground (Augochlora uses partially rotten logs). Some are primitively eusocial; in such cases usually a female guards the entrance to the burrow by plugging it with her head. Generally the main burrow is vertical; it sends horizontal branches, each branch ending in a solitary cell.”  One of your images illustrates a Metallic Sweat Bee flying toward a hole that has its opening plugged by the head of another bee.

OK, I guess I have seen both small and larger sweat bees in the yard.  I’ll try to get some better photos.  I’m seeing several different kinds of bumblebees also.
Thank you Daniel,

Metallic Sweat Bee

Metallic Sweat Bee

Wonderful Daniel!  I noticed that each opening of the three or four there would often have a bee in it, I kept waiting to try to get a good picture, but they would duck back down.  I have lots of mostly native flowers blooming in my yard right now, it is delightful to get native insects too.
I always thought sweat bees, or what we called sweat bees, were not as large as these.  These are closer to the size of honey bees ( though these in the picture are smaller than honey bees) .  Sorry I didn’t have anything to compare it to in the picture.
Thank you for your good work,

Hi Jeanette,
Some species of Sweat Bees are quite small.  Bee Informed lists their size range as between 1/4 and 3/4 inch.



Location: Denver, Colorado

One Response to Metallic Sweat Bee

  1. Kathy Lee says:

    This was very informative. I just found and area in my yard where I discovered these bees starting their holes by my garden. Beautiful to look at and hoping they don’t care about what I’m doing. Not sure if they sting but I’ll research it now that I know what they are! Thank you.

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