The Texas Striped Sweat Bee (Agapostemon texanus) is one of the most common native bees in San Diego County and can be seen year-round. That said, its smaller size (about half that of a honey bee) means it isn’t being noticed by everyone. For shame because their bright green metallic colors are just stunning.

Before I go on, let’s address the elephant in the room. Why are they called ‘sweat’ bees? Do bees sweat? If so, do they use deodorant? Maybe they don’t need to since they hang on nice smelling flowers all day.

Okay, enough of the nonsense, here is the dirt: bees do not sweat, yet they are occasionally attracted to human sweat! Why? They simply like to supplement their diet with moisture and salt. I have been around A LOT of sweat bees and have only experienced this interaction once, so don’t be wary about them landing on you after a jog through our beautiful Mission Trails Regional Park trails. It most likely will never happen.

Male and female Texas Striped Sweat Bees are easy to tell apart: females are all green, while males sport black and yellow bands on their abdomen, as in our observation seen at: inaturalist.org/observations/64999010 by park volunteer Brian Wright.

There are other species of Striped Sweat Bees (genus Agapostemon) that are very similar and hard to tell from A. texanus.

For example, if you ever see a sweat bee with a striped abdomen and pollen balls on the hind legs, you are indeed looking at a different, but extremely similar species: the Honey-tailed Striped Sweat Bee (Agapostemon melliventris). Females of A melliventris also have a black and yellow striped abdomen and since male bees do not collect pollen, that’s one way to tell these two related species apart.

Texas Striped Sweat Bees are generalists, which means they are not too picky about what flowers they forage on.

That’s one reason they are found just about everywhere in San Diego County, except in the desert areas. You might even find them in your yard. However, since they are ground nesters, they need access to undisturbed soil. Like most bees, Agapostemon texanus is a solitary species. This means a female will not share her nest with another bee, and although it is entirely possible another female will nest nearby, the tunnels from the two nests will not connect.

A nest consists of one main tunnel with several narrower branching tunnels ending in a single cell. The female will deposit an egg and food for a larva in each of these cells and then seal them up. When the egg hatches, the larva will consume the food (a ball of pollen/nectar), pupate, and emerge as an adult, usually in the spring. Females have been observed nesting in horizontal soil as well as vertical cliffs.

Meanwhile, males have been spotted in “slumber parties”.

They will sometimes congregate on one branch or leaf and rest together through the night. However, they seem to be unaware that much fun could be added with some facials, movies, and pillow fights.

Here is a video (youtu.be/99LhmtLeoeY) with both male and female foraging on Chaparral Bushmallow at Cabrillo National Monument. Enjoy.

Photo credit: Brian Wright.