As the gardens and orchard were both newly installed this year, that part of the property has been host to numerous insect species since spring, some good, some bad, and a few ugly in recent months. As we produce everything organically, we don’t spray here, beyond the occasional angst-ridden jet of water targeted toward hoards of aphids swarming on the sorrel in the early mornings, and some days it seems we’re farming more aphids and leaf-hoppers, than food. That said however, we realize that it will take time to bring balance to the gardens here, and although the pests seem to be winning, for the moment, the beneficial insects are beginning to establish a notable presence here, including this Agapostemon texanus.
This female Agapostemon is the first sweat bee I’ve spied here. For as small as they are, they’re quite dazzling when the sunlight catches their iridescent beetle-green colors. Agapostemon bees are native to North America, with approximately 5 species being native to the Pacific Northwest, of which A. texanus is one.
Agapostemon texanus, is in the family Halictidae. The bees within the Agapostemon genus are commonly called ‘Sweat Bees’ because they’re attracted to human sweat, and savor it for its sodium content.
Now that we know they’re attracted to human perspiration, perhaps I didn’t find this female. It seems she most likely found me!
Before we encountered each other, I’d just spent a few hours weeding on the sunny, exposed slopes in the orchard, I admit to being almost completely melted into a puddle. When I first encountered her, I wasn’t sure if she was irritated with me. The honeybees mostly go about their business, and didn’t seem to mind my lens pushed up into the Verbena, but this little green Sweat Bee seemed to relish getting right in my face, as if I was invading her personal space, but it turns out these are actually very docile bees. I just happened to be somewhat irresistable that afternoon!
In addition to soggy humans, bees in the genus Agapostemon are floral generalists, dining on a wide selection of flower species. At the moment, with little in bloom here, we’re seeing them on both Verbena lasiostachys, and some heirloom Italian White, and Lemon Queen sunflowers planted along the edge of the vegetable gardens, and for now, this seems to be where most of our Sweat Bees are lurking.
This snappy fellow was playing hide-and-seek amidst the Italian White sunflowers.
Relative to the honeybees, they seem quite frenetic, zipping about rather unpredictably between the flowers, which makes photographing them truly challenging!
As you can see, Agapostemon texanus are robust, strikingly colored metallic green bees. However, these bees are significantly smaller than your average European honey bee, medium sized, ranging from 0.3 to 0.6 inches long. Females are completely green, like the one below.
Whereas the males have a bright metallic green head and thorax, but a striped, almost wasp-like abdomen.
Females carry pollen on brushes of hair, called scopa, on their hind legs. Apparently the female Sweat Bees are relatively fast-flying, and males supposedly fly more slowly, primarily because they are searching the flowers for females. With my camera in tow though, this male was much more difficult to capture than the female. Probably just the photographer’s curse.
Most Agapostemon are solitary ground-nesting bees. Two to 24 females will share a single nest, but each individual will build, and provision, its own nest cells. Agapostemon nest in deep vertical burrows, or soil banks. We had planned a retaining wall along the length of the road-cut leading to the gardens. However, last year, in the winter months, we noted a number of Coast Newts lurking in small burrows in this bank along the road-cut, and apparently the bees need this type of exposed vertical area for nesting too.
As there are no structures of concern downhill, like sheds, or the house, we’ve chosen to plant this bank with some native perennials instead, to help curb erosion, and the low retaining wall will now only be placed behind our (as yet unbuilt, not to mention, a year behind schedule) shed out in the vegetable gardens.
Although we’ve enjoyed seeing these bees, we want to encourage more native pollinators to visit Curbstone Valley. We recently received our native wildflower seed order, and now have a wide collection of both annual and perennial native blooms to plant this fall for the benefit of these critical insects. Thanks to Town Mouse and Country Mouse, who reminded us this past weekend that a local native nursery was having a blowout fall plant sale, we stocked up on some bee-friendly species that weren’t already in our seed order, and with a local CNPS plant sale coming up in October, we’re expecting the bees will be far better taken care of than the rest of us, come spring!