Backyard Orchard News
The European honey bee, also known as the Western honey bee, has been in the United States for s-o-o-o long that we think it's a native.
It's not. European colonists brought the honey bee (Apis mellifera) to the Jamestown colony (Virginia) in 1622. The native Americans called it "the white man's fly." And the honey bee wasn't even introduced to California until 1853. That was in the middle of the California Gold Rush, 1848-1858, when it arrived in the San Jose area.
Our ancestors quickly became quite fond of the industrious little pollinator and honey/wax producer buzzing around them.
Today, as they did, we frequently see non-native and native bees sharing nectar resources, such as in the photos below of honey bees and yellow-faced bumble bees (Bombus vosnesenskii).
We're often asked: "Do honey bees, being an invasive species, impact the native bees?"
We put that question to Extension apiculturist Eric Mussen of the UC Davis Department of Entomology and Nematology. He's served as California's Extension apiculturist since 1976, almost 40 years.
His answer: "We do not have a definitive answer to that question. But, since honey bees have been living in what is now the U.S. for just short of 400 years, it is likely that honey bees and native bees determined, long ago, how to partition resources at any particular location so that both species survived. It is true that only honey bees can be moved into and out of a specific location overnight, and that might put a stress on local populations of native bees, but I never have heard of honey bees eliminating native bees from any particular spot."
That's the buzz on bees.
A honey bee and a yellow-faced bumble bee sharing a purple coneflower, Echinacea purpurea. (Photo by Kathy Keatley Garvey)
Two's company: A honey bee and a yellow-faced bumble bee forage on Scabiosa. (Photo by Kathy Keatley Garvey)
- "I just saw a golden bumble bee. I think it's a new species! Can I name it?"
- "I just saw a huge bee and it's gold in color and all fluffy with green eyes!"
- "I just saw a huge bumble bee flying around in our backyard. It's yellow and I think it's a pest."
It's the male Valley carpenter bee, Xylocopa varipuncta, which native pollinator specialist Robbin Thorp, emeritus professor of entomology at the Department of Entomology and Nematology at the University of California, Davis, calls "the teddy bear" bee.
Like all male bees, it doesn't sting.
But what's unusual about this bee is its color, golden with green eyes. It's sexual dimorphism at its best, because the female Valley carpenter bees are solid black.
The Valley carpenter bee is the biggest carpenter bee in California. And it scares the living beejeez (dead beejeez, too) out of young children, teenagers, and adults. Just about everybody and everything, including the family dog and cat.
As Thorp told us several years ago for a news story:
"Xylocopa varipuncta occurs in the Central Valley and southern California, Arizona, New Mexico and southward through Mexico. It is large (about the size of a queen bumble bee), with all black females and golden/buff-colored males with green eyes. Females have dark wings with violet reflections."
Some folks think it's a pest. It's not. It's a pollinator. Let it "bee."
Male Valley carpenter bee, Xylocopa varipuncta, is blond with green eyes. (Photo by Kathy Keatley Garvey)
Female Valley carpenter bee is solid black. (Photo by Kathy Keatley Garvey)
Monarchs and milkweed are in the news again.
As well they should be.
The declining monarch population, coupled with the decreasing scarcity of their host plant, the milkweed, is disturbing. The larvae of the monarch butterfly (Danaus plexippus) feed exclusively on milkweeds. No milkweed, no monarchs.
Butterfly expert Art Shapiro, distinguished professor of evolution and ecology at UC Davis, says the problem hasn't totally reached California yet. "The 'dearth of milkweed' problem is primarily an East/Midwest problem, due to increased use of Roundup since the introduction of 'Roundup-ready' GM crops. It's quite real. There is no such problem out here--at least yet--but there is a new milkweed pathogen that may cause one! Dave Rizzo (UC Davis Department of Plant Pathology) and I hope to publish on it shortly. No harm in planting milkweeds, but the problem isn't a California one, at least not yet."
Journalist-photographer Alessandra Bergamin, writing in the Feb. 18 edition of Bay Nature: Exploring Nature in the San Francisco Bay Area, says that "the number of monarchs overwintering in Mexico's Oyamel fir forest has reached an all-time low," quoting the World Wildlife Fund in Mexico. "The reports suggest that factors such as loss of habitat, climate change and use of insecticides have contributed to the decline."
The situation in California, however, looked better than bleak last year. A little better. "Monarch butterfly populations in California's coastal overwintering sites showed a slight — and surprising — rebound in 2013 after more than a decade of dwindling numbers," Bergamin wrote. "The 2013 Western Monarch Thanksgiving Count tallied 211,275 monarchs at 162 sites from Sonoma County to San Diego County, up from 144,812 the year before."
Over the past two decades, however, the Western monarch population has dramatically declined in California, she pointed out in her article, "Western Monarch Population Hanging On." The downward trend is expected to continue.
Meanwhile, the Xerces Society for Invertebrate Conservation, headquartered in Portland, Ore., has posted a seed finder resource so folks can find milkweed seed in their state and plant the seeds in their gardens, parks, landscapes, restoration areas and on farms.
Oakland parks supervisor Tora Rocha is taking it one step further. She is collecting the monarch caterpillars, rearing them, and releasing the adults in the Lakeside Gardens at Lake Merritt. Her newly formed Pollinator Posse has sparked the interest of volunteers, who range from school children to city council members. They all want to save the monarchs.
Rocha bans pesticides and herbicides from her pollinator gardens. “For the past fifteen years the gardens have had a pesticide-and herbicide-free policy,” Rocha told writer Constance Taylor of Wild Oakland, which offers free, Oakland-centered environmental education. “We also rely on volunteers contributing thousands of hours to keep our parks maintained--about 75% of the work is done by volunteers.”
Rocha says it's not enough to be a custodian of the land: it's important to be a steward of the land and protect the pollinators. She's created a video, posted on YouTube, that explains what she and the other Pollinator Posse members do.
Rocha and colleague Eddie Dunbar of the Insect Sciences Museum of California and a fellow Pollinator Posse member, recently visited UC Davis to share information with Shapiro and native pollinator specialist Robbin Thorp, emeritus professor of entomology.
Another person keen on butterflies is Sally Levinson of Berkeley, who writes a blog on butterflies and is publishing educational videos, including "Secret Lives of Monarchs" and "In the Company of Wild Butterflies." As a graduate student at UC Riverside, Levinson studied with major professor Bruce Hammock, now a distinguished professor of entomology at UC Davis. (He maintains a joint appointment with the Department of Entomology and Nematology and the UC Davis Comprehensive Cancer Center.)
As an aside, the Bohart Museum of Entomology at UC Davis offers a "Got Milkweed?" t-shirt spotlighting the monarch and its host plant. The work of doctoral candidate Fran Keller and Bohart volunteer/naturalist Greg Kareofelas, the t-shirt is available online or at the museum, located in Room 1122 of the Academic Surge building on Crocker Lane.
Want monarchs? Plant milkweed.
A monarch butterfly nectaring on a zinnia. (Photo by Kathy Keatley Garvey)
This is a milkweed, the host plant of the monarch. This photo was taken in the Melissa Garden, Healdsberg. http://www.themelissagarden.com/ (Photo by Kathy Keatley Garvey)
It may not be the farmer's friend, but it's the beekeeper's friend.
Wild radish (Raphanus raphanistrum), a member of the mustard family, Brassicaceae, is considered a weed, but I consider it a flowering plant for bees when I see it along roadsides and parks and lining orchards and vineyards.
As winter leaves us and spring snuggles closer, the bees are all over the wild radish. Typically white or a pale pink with pale pinkish-purplish veins, it's an early bloomer. Often you see mustard and "the rad" growing together.
If a weed is "a plant that is not valued where it is growing," then this most certainly is not a weed.
At least to bees, beekeepers and photographers.
A honey bee heading for wild radish. (Photo by Kathy Keatley Garvey)
Honey bee in motion. (Photo by Kathy Keatley Garvey)
The painted ladies are on move.
Scores of painted ladies (Vanessa cardui) are now migrating north from their overwintering sites near the U.S. Mexico border.
"Fascinatingly, they arrived in Prescott, Ariz., the same day (as the ones spotted in Benicia)," said butterfly expert Art Shapiro, distinguished professor of evolution and ecology at the University of California, Davis. "I think they're all from south of the border." The annual migration north varies, but can take place as early as late January and as late as mid-April.
The painted ladies spend the winter in the desert, where in the late winter, they breed on desert annual plants, Shapiro says. The adults emerge in February or March and immediately migrate into the Central Valley and foothills, where they breed. Around May, here in the Central Valley, you'll see the caterpillar offspring munching on borage, thistles, fiddleneck and mallows. Then the adults head toward the Pacific Northwest.
"The painted lady moves northward in a generational wave as the season progresses," Shapiro says on his website. "Frequently it disappears altogether from the lowlands in summer. Beginning in August the movement reverses and butterflies head south toward the desert wintering grounds."
"There is no evidence that this species overwinters successfully anywhere in our area, except for very rare individuals maturing in midwinter from really late autumnal larvae."
The painted lady migration may not be as popular as the monarch (Danaus plexippus) migration, but it's fascinating just the same.
Shapiro, who has monitored the butterfly population of California's Central Valley for 42 years, will be speaking at noon on Monday, March 24 on "Ecological Communities and the March of Time" in the Commonwealth Club, 595 Market St., San Francisco. For program detail and registration, please see the club website. His talk is open to the public. For a discount, access the website and use the coupon code, "friendsforshapiro," said spokesperson Chisako Ress (firstname.lastname@example.org).
A female butterfly, a painted lady, nectaring on Spanish lavender on March 8 in the Benicia Community Garden. (Photo by Kathy Keatley Garvey)
Painted lady twists around for a better shot at the nectar. (Photo by Kathy Keatley Garvey)