Some folks call them "bumble bees," but they're not.
In size, the female Valley carpenter bee (Xylocopa varipuncta) resembles a bumble bee, but certainly not in color.
The female Valley carpenter is solid black with metallic wings. The male of the species is a green-eyed blond, fondly known as "the teddy bear" bee because it's fuzzy-wuzzy and cannot sting. Entomologists will tell you that the male and female are dramatic examples of sexual dimorphism. Yes, they are!
We've been seeing a lot of female Valley carpenter bees lately on our blue spike salvia, (Salvia uliginosa). They engage in nectar-robbing: this occurs when bees circumvent the usual plant-pollinator relationship and "cheat" by entering a flower from the outside to steal nectar. They drill a hole in the corolla to reach the nectar, thus avoiding pollination or contact with the anthers.
Similar-looking insects include bumble bees, cactus flies and horse flies, according to California Bees and Blooms, a Guide for Gardeners and Naturalists,by UC-affiliated authors Gordon Frankie, Robbin Thorp, Rollin Coville, and Barbara Ertter. "Carpenter bees are shinier and have less hair than fuzzy bumble bees. Carpenter bees have two pairs of wings, and they have long, slender, elbowed antennae, while fly mimics have only one pair of wings, and short stubby antennae."
The Valley carpenter bee is California's largest carpenter bee.
They're large but they're elusive. They usually don't linger long for you to grab a photo. This one did. It was early in the morning, and like a true human morning person, she declined to move fast./span>
Bee-hold, the eye of a bee-holder.
When you have a "Bee Crossing" sign in your pollinator garden, odds are that bees will cross right in front of that sign.
And it's not always a honey bee.
European wool carder bees (Anthidium manicatum) zip around our blue spike sage (Salvia uliginosa), chasing other bees away and trying to save it for "their girls"--per chance to mate with them.
In the photos below, a male European wool carder bee paused to sip some nectar before continuing his rounds.
Little did he know, a honey bee (on the sign) was staring right at him.
As its name implies, the European wool carder bee, Anthidium manicatum, is a native of Europe. American entomologists initially detected his "immigrant ancestor" in the United States (New York) in 1963, and the species spread west. The carder bee (so named because the female "cards" fuzz from plants for her nest) was first recorded in California (Sunnyvale) in 2007.
The news is disturbing but not unexpected.
Scientists are linking global climate change to one reason why the worldwide population of bumble bees is declining.
An article published Sept. 28 in the journal Ecology Letters by Florida State University (FSU) researchers showed that bumble bees just aren't getting enough floral resources.
For the study, lead researcher and postdoctoral fellow Jane Ogilivie and six colleagues examined three subalpine bumble bee species in Colorado's Rocky Mountains, and found that the changing climate means fewer flowers.
"Knowing whether climate variation most affects bumble bees directly or indirectly will allow us to better predict how bumble bee populations will cope with continued climate change," Ogilivie told the FSU News Service in a press release. "We found that the abundances of all three bumble bee species were mostly affected by indirect effects of climate on flower distribution through a season."
The FSU News Service aptly headlined the research a "Stinging Report."
"When researchers think about flower effects on bees, they typically consider floral abundance to be the most important factor, but we found that the distribution of flowers throughout a season was most important for bumble bees,” Ogilivie said. “The more days with good flower availability, the more bees can forage and colonies can grow, and the bigger their populations become. We now have longer flowering seasons because of earlier snowmelt, but floral abundance has not changed overall. This means we have more days in a season with poor flower availability.”
The researchers wrote in their abstract: "Climate change can influence consumer populations both directly, by affecting survival and reproduction, and indirectly, by altering resources. However, little is known about the relative importance of direct and indirect effects, particularly for species important to ecosystem functioning, like pollinators. We used structural equation modelling to test the importance of direct and indirect (via floral resources) climate effects on the interannual abundance of three subalpine bumble bee species. In addition, we used long-term data to examine how climate and floral resources have changed over time. Over 8 years, bee abundances were driven primarily by the indirect effects of climate on the temporal distribution of floral resources. Over 43 years, aspects of floral phenology changed in ways that indicate species-specific effects on bees. Our study suggests that climate-driven alterations in floral resource phenology can play a critical role in governing bee population responses to global change."
Bumble bee expert Robbin Thorp, distinguished emeritus professor of entomology at the University of California, Davis, long ago sounded the alarm that bumble bees are in trouble. He is the co-author of Bumble Bees of North America: an Identification Guide (Princeton) and California Bees and Blooms: A Guide for Gardeners and Naturalists.
The last bumble bee we saw--the last of the season--was on Sept. 23 at Kate Frey's pollinator garden at the Sonoma Cornerstone, Sonoma. It was a yellow-faced queen bumble bee, Bombus vosnesenskii, nectaring on a spiked floral purple plant, Salvia ‘Indigo Spires' (Salvia farinacea x S. farinacea). The queen had apparently emerged from hibernation to find food on that warm summerlike day.
I knelt to capture some images.
"Oh, it's just a bumble bee," scoffed one tourist, casually sipping a glass of wine. "They're everywhere."
Sadly, they're not.
Think bees. Think butterflies. Think plants that will attract them.
Members (you can join online or at the gate) can peruse and purchase plants from 9 to 11 a.m., and the general public from 11 a.m. to 1 p.m. Members save 10 percent off their plant purchases, while new members receive an additional $10 off as a thank-you gift.
You can chat with the Arboretum folks to pick out that special plant you're seeking. They also provide an online list of available plants and/or you can download The Life After Lawn: Garden Gems Plant List.
Many of the plants at the sale are All-Stars. What's an All-Star? The Arboretum horticultural staff has identified "100 tough, reliable plants that have been tested in the Arboretum, are easy to grow, don't need a lot of water, have few problems with pests or diseases, and have outstanding qualities in the garden." Many are California native plants and support native birds and insects. Most All-Star plants can be successfully planted and grown throughout California.
If you miss the Oct. 7th sale, not to worry. There are two more fall plant sales:
Saturday, Oct. 21
Open to the Public: 9 a.m - 1 p.m.
Saturday, Nov. 4
Public Clearance Sale: 9 a.m. - 1 p.m.
It's a good idea to BYOB (Bring Your Own Box), BYOW (Bring Your Own Wagon) or BYOC (Bring Your Own Cart).
While you're there, check out the 100-acre Arboretum, including the nearby Ruth Risdon Storer Garden (aka Storer Garden), a Valley-wise garden,and the Carolee Shields White Flower Garden and Gazebo (aka White Garden). Have you seen all of the 17 special gardens and collections?
They're called "living museums" because that's what they are. Living museums. And especially when they attract pollinators!
If you're looking for plants to attract pollinators, including bees and butterflies, then the UC Davis Arboretum's Plant Sale on Saturday, Oct. 22 is the place to "bee."
A public fall clearance sale will be held from 9 a.m. to 1 p.m. at the Arboretum Teaching Nursery on Garrod Drive, UC Davis campus. It will feature a "wide selection of Arboretum All-Stars, California natives, and gorgeous drought-tolerant plants," officials said. Members (new members can join at the door) save 10 percent and also reap other benefits.
The sale will include more than 16,500 plants and more than 450 varieties.
Will they have milkweed? Yes.
"It looks like we'll have plenty of milkweed, two varieties--Kotolo (Asclepias eriocarpa) and showy milkweed (Asclepias speciosa)," said Katie Hetrick, director of communications.
Will they have butterfly bush (Buddleia)? Yes.
"We have a ton of Buddleia," said Hetrick, mentioning just a few: Magenta Munchkin, Dark Dynasty, Buzz, Orchid Annie, Purple Haze, Lavender Cupcake--and "The Chips": Lilac Chip, Pink Micro Chip, and Blue Chip Jr.
"And let's not forget all the Salvias!" Hetrick said. "Those are a nectar fave with pollinators including butterflies, bees and hummingbirds!" Among the Salvias on sale: Bee's Bliss, Pacific Blue, Marine Blue, Pozo Blue, Debbie's Rose, Little Kiss, Red Swing, Violet Riot, Royal Bumble, Hot Lips, and Scott's Red.
Taylor Lewis, UC Davis Arboretum and Public Garden Nursery Manager, related that pipevine, the host plant of the pipevine swallowtail butterfly (Battus philenor), will be available.
Ellen Zagory, director of horticulture, listed some of her favorite sunflower family plants that attendees can buy:
- Aster 'Monch'
- Coreopsis, 'Little Penny'
- Coreopsis, 'Enchanted Eve'
- Coreopsis, 'Red Elf'
- Echibeckia, 'Summerina Brown'
- And lots of Echinacea (cone flowers)
For a full list of the plants available, download the PDF.
And, it's interesting to see what folks in the area have planted instead of lawns. The Aboretum's web page offers great ideas.
Do you know how much acres in the United States are planted in lawn? Huffington Post reports in a 2015 news story: "According to a new study from NASA scientists in collaboration with researchers in the Mountain West, there is now an estimated total of 163,812 square kilometers, or more than 63,000 square miles, of lawn in America — about the size of Texas."
All that manicuring, all that water, all that work. And little or no food or shelter for the pollinators.
Every well-manicured lawn "uses up to 900 liters of water per person per day and reduces sequestration effectiveness by up to 35 percent by adding emissions from fertilization and the operation of mowing equipment," Huffington Post says.
Indeed, lawn is our nation's single largest "crop."
But it doesn't have to be. There IS life after lawn. And there is MORE life after lawn.