"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.
Let's hear it for the sweat bee.
It's one of the many tiny bees that ought to be honored and recognized during Pollination Week, June 21-27, but it's often overlooked.
We've been seeing many of this species, Halictus tripartitus, in our pollinator garden in Vacaville. It's also called the "Tripartite Sweat Bee."
Thomas "Tom" Zavortink, a research entomologist and associate at the Bohart Museum of Entomology, UC Davis Department of Entomology and Nematology, noted why this one is Halictus tripartitus. "The abdominal terga appear to have apical hair bands, suggesting Halictus, and the scutum appears to have a slight metallic coloration, which along with the small size suggests Halictus tripartitus." Zavortink focuses on the systematics and biology associated with mosquitoes and solitary bees.
Most Halictus are generalist foragers, according to the Great Sunflower Project. "They use all sorts of genera of plants from the Asteraceae to Scrophulariaceae. They are very common on composites (daisy-like disc and ray flowers) in summer and fall."
We've seen them on everything from mustard to milkweeds to catmint to rock purslane, from spring to fall. They also appear regularly on the tower of jewels (Echium wildpretii).
Let's hear it for the sweat bee, an overlooked and underloved little pollinator.
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.
Honey bees aren't the only bees out foraging.
We saw our first native bee of the season on Jan. 25 at the Benicia Capitol State Historic Park.
Native pollinator specialist Robbin Thorp, distinguished emeritus professor of entomology at the UC Davis Department of Entomology and Nematology, identified it as a female sweat bee, Halictus rubicundus.
"The head shape, lack of long curled hairs below at the base of the hind leg, and the bent basal vein in the wing" helped him identify it as a Halictus. The lack of facial foveae confirmed it was not an Andrena.
"Nice early record for this species," added Thorp, who is the co-author of California Bees and Blooms: A Guide for Gardeners and Naturalists (Heydey) and Bumble Bees of North America: An Identification Guide (Princeton University Press.)
Halicutus rubicundus is found in Europe, northern Asia, and across the United States and Canada, according to the book, The Bees in Your Backyard, A Guide to North America's Bees, by Joseph S. Wilson, assistant professor of biology at Utah State University, and Olivia J. Messinger Carril, who received her doctorate in plant biology from Southern Illinois University and "has been studying bees and wasps for more than a decade," according to the publisher, Princeton University Press.
You can see more images of this sweat bee on BugGuide.Net.
So, one sweat bee down. Hundreds more to go as the seasons unfold.
The UC Davis Departmentof Entomology and Nematology has scheduled a fifth anniversary celebration of its bee garden on Saturday, May 2.
It's difficult to believe that the Häagen-Dazs Honey Bee Haven is five years old. But it is, and the event will take place from 10 a.m. to 2 p.m.
The half-acre bee garden, planted in the fall of 2009, is located on Bee Biology Road next to the Harry H. Laidlaw Jr. Honey Bee Research Facility, west of the central campus. A public ceremony will be held from 10:30 to 11:30 a.m.
Michael Parrella, professor and chair of the department, will welcome the crowd at 10:30 a.m. Lynn Kimsey, director of the Bohart Museum of Entomology and professor of entomology, was the interim chair of the department and directed and organized the installation of the garden. It was planted in 2009, thanks to a generous donation from Häagen-Dazs. More than 50 percent of their ice cream flavors depend on pollination.
Raj Brahmbhatt, associate brand manager of Häagen-Dazs Ice Cream at Nestle USA, Dreyer's Ice Cream company, will speak at 10:50 a.m. on “What the Haven Means to Us.”
Christine Casey, manager of the haven, will discuss “What Your Donations Mean to the Haven” at 11:15.
What can you do in the bee garden? Walk the paths. Admire the flowers. Admire the pollinators. Learn how to observe and identify bees, what to plant to help bees, and how to use native bee houses. There also will be beekeeping demonstrations and garden tours.
The garden is open to the public from dawn to dusk every day. Admission is free. Tours (a nominal fee is charged) can be arranged with Casey at firstname.lastname@example.org. To book a tour, access the website and click on "Visit Us."
The design is the work of a Sausalito team--landscape architects Donald Sibbett and Ann F. Baker, interpretative planner Jessica Brainard and exhibit designer Chika Kurotak--the winners of the international design competition.
Read more about the garden here! How it all began, who the founding manager was and the honor she and the 19 volunteer gardeners received, and who built the state-of-the-art fence around the garden.
We remember when it was an open field with jack rabbits bounding through the tall grass and red-tailed hawks circling above. The rabbits still bound (but not inside the garden) and the hawks still circle looking for prey.