"Sweat bees have earned their common name from the tendency, especially of the smaller species,to alight on one's skin and lap up perspiration for both its moisture and salt content."
So write University of California scientists in their award-winning book, California Bees and Blooms, a Guide for Gardeners and Naturalists.
California has some 1600 species of undomesticated or wild bees, point out the authors (Gordon Frankie, Robbin Thorp, Rollin Coville and Barbara Ertter).
And one of them is the sweat bee, Halictus ligatus, a member of the family Halictidae. It's a medium-sized, ground-nesting bee with a striped abdomen.
This week one of these species (as identified by research scientist John Ascher) looked especially striking on a Black-Eyed Susan, Rudbeckia hirta, a member of the Aster (Asteraceae) family. Both the plant and the bee are natives.
Several years ago we managed to photograph a flameskimmer dragonfly, Libellula saturata, munching on one of these sweat bees. Not a good day for that little gal!
No dragonflies were around, however, when we watched this one foraging on a Black-Eyed Susan.
Did you know that the Black-Eyed Susan is the designated state flower of Maryland? And that it was the inspiration for the University of Southern Mississippi's school colors (black and gold)? And that it's a larval host to butterflies such as the bordered batch, gorgone checkerspot and silvery checkerspot?
Who knew? If you plant it, though, be aware that it is toxic (when ingested) to cats.
She's in Vacaville, Calif., and the garden she is visiting today is a veritable oasis of blooms: Mexican sunflower (Tithonia rotundifolia), butterfly bush (Buddleia davidii) and lavender (Lavandula). And it's filled with bees.
That's why she's here.
Just as crooks rob banks because "that's where the money" is, predators hang around pollinator gardeners because "that's where the prey is."
The predator is hungry. Ah, what's that? She glides from her perch, her wings glowing in the morning sunshine. She circles the garden and quickly returns with a pollen-laden bee in her mouth.
She ignores the photographer sitting a few feet from her and begins to eat.
But what bee? What bee is on the dragonfly menu?
Native pollinator specialist Robbin Thorp, distinguished professor of entomology at the University of California, Davis, identified the bee from one photography angle (second photo below): a female sweat bee, genus Halictus.
"But what species?" asked Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology at UC Davis.
Here's another angle (first photo below), showing the head.
That's all it took. "The bee is a female of Halictus ligatus, based on the head shape, especially the pointed part of the back right side of the head," Thorp said.
Amazing. Who would know that?
Robbin Thorp, that's who.
Robbin Thorp knows bees like we know the way home. World-renowned for his bee expertise, he co-authored of California Bees and Blooms: A Guide for Gardeners and Naturalists, and Bumble Bees of North America: An Identification Guide and co-teaches at The Bee Course, an American Museum of Natural History workshop held annually at the Southwestern Research Station, Portal, Ariz. The workshop is geared for conservation biologists, pollination ecologists and other biologists who want to gain greater knowledge of the systematics and biology of bees. This year's workshop is set Aug. 21-31.
Meanwhile, the dragonfly polishes off her meal, gazes at the photographer (What, are you still here? Sorry, I don't share!), and off she goes, zigzagging over the garden.
She will be back. She's punched only one hole of his meal ticket. Many holes--and many bees--remain.
There's an old saying that "good things come in threes."
Well, they also come in twos.
When insect photographers manage to get two insects in the same photo, it's a "two-for."
Autumn is in full swing now, and the colder weather is settling in, but insects continue to provide a variety of diverse photo opportunities.
Two of a kind: a pair of mating Gulf Fritillary butterflies on a passionflower vine, two female sweat bees on goldenrod, and two female Valley carpenter bees on a passion flower.
Gulf Fritillary butterflies: Agraulis vanillae.
Sweat bees: Halictus ligatus.
Valley carpenter bees: Xylocopa varipuncta.
But if you look closely, there are three insects in the Valley carpenter bee photo. The other is a Gulf Fritillary caterpillar.
Good things come in threes, too.
You often see a single solitary bee on a sunflower.
Perhaps it's a sunflower bee (Svastra) or a honey bee (Apis mellifera).
But four on one? Sharing a sunflower?
If you look closely at the photo below, you'll see Svasta, Apis and a sweat bee, Halictus ligatus on the sunflower head, plus another sweat bee, Halictus triparitus, "coming in for a landing," says native pollinator specialist Robbin Thorp, emeritus professor of entomology at the University of California, Davis.
If you're curious about the sunflower bee, "Our Svastra obliqua expurgata is a native bee and exhibits a preference for sunflowers which are also native and other relatives of sunflower," Thorp said. "The genus Svastra has over 20, all occurring in North and South America. All are ground nesting solitary bees. Some other species of Svastra exhibit preferences for pollen from evening-primrose or cactus.'
The garden is open from dawn to dusk, with free admission. You can do self-guided tours. Soon, probably next spring, the UC Davis Department of Entomology will offer guided tours.
Bee friendly garden? Indeed. In fact, Thorp has found 75 different species of bees--and counting--since he began monitoring the plot in October 2009, a year before it was planted.
If you wander through the garden, be sure to bring your camera, especially if you love insects and flowers.
You may find five species of bees sharing a sunflower!
If you're in the right spot at the same time, you may get a double bonus: a non-native bee and a native bee on a native plant.
We took this photo in Healdsburg last week of a non-native bee (the common European or Western honey bee, Apis mellifera) and a native sweat bee (Halictus ligatus) sharing a plant native to the Americas: the sunflower.
A golden moment.