- Author: Kathy Keatley Garvey
Where, oh where, is that first bumble bee of the year?
It's about this time of the year when the queen black-tailed bumble bee, Bombus melanopygus, and the queen yellow-faced bumble bee, Bombus vosnesenskii, emerge.
One of our area readers asked if there's a chart or calendar indicating what time of year the various native bees emerge. One of the best sources is native pollinator specialist Robbin Thorp, distinguished emeritus professor of entomology at the University of California, Davis. (By the way, he's giving a public presentation on native bees at 1:30 p.m., Saturday, Jan. 24 at Solano County's Rush Ranch Nature Center, Suisun City. All interested persons are invited; there's no admission.)
"Each species of bee has its own particular season," Thorp says. "Some start in late winter to early spring, others start late spring, early summer. Some don't fly until fall. Some bees, especially our social bees (honey bees, bumble bees and some sweat bees) fly most of the flowering year (January-February into October-November)."
"It's probably best to frame the bee calendar in context of the bloom of various plants," Thorp points out. "Manzanita is one of the first flowering shrubs and when they come in to bloom that is the time to look for queens of our two early bumble bee species, Bombus melanopygus and B. vosnesenskii. Some of our large digger bees like Habropoda and some Anthophora come on during that bloom. In the vernal pools, early flowering starts in late February and some of our solitary ground nesting mining bees, Andrena start about then. When the red bud comes into bloom about mid-March the Blue Orchard Bee (BOB), some other species of bumble bees, and some sweat bees come out. Leafcutting bees (Megachile) and some long-horned digger bees (Melissodes and Svastra) start their activity about mid-May. "
A great book to learn about native bees and the flowers they visit is the newly published California Bees and Blooms: A Guide for Gardeners and Naturalists (Heyday). It's co-authored by Gordon Frankie, Robbin Thorp, Rollin Coville and Barbara Ertter, all with UC Berkeley connections.
For example, if you look up manzanita (genus Arctostaphylos and family Ericaceae), in California Bees and Blooms, you'll see that there are more than 90 species and subspecies in California, and you'll learn which bees visit them. The authors provide a description of the plant, its origin and natural habitat, its range and use in urban California, its flowering season (late winter to early spring), the resources it provides for bees (pollen and nectar), bee ecology and behavior, and gardening tips.
The book is a treasure.
As are the bees!
- Author: Kathy Keatley Garvey
Writing for the Nature journal, Sharon Levy recently examined pollination studies that focus on the importance of pollinators and the plants they frequent.
Levy mentioned the work of conservation biologist Claire Kremen of UC Berkeley; Rachael Winfree, a pollination biologist at Rutgers University in New Brunswick, N.J.; and native pollinator specialist Neal Williams of UC Davis.
Williams led one of the studies that found that "most native bees are far less picky than was imagined," Levy wrote. The study showed that "bees collect pollen from both alien and native plants in proportion to a plant's abundance in the landscape," she related. "In highly disturbed habitats, bees make greater use of alien plants--not because the bees prefer them, but simply because introduced plants are far more common where people have transformed the landscape."
Last year Williams received a three-year federally funded research grant aimed at improving pollinator habitat plantings in nationwide agricultural settings. Williams said at the time:
“Recent declines in honey bee populations and the threat of losses in pollination service to economically important crops has raised awareness of the importance of restoring and conserving native bee diversity and abundance. We will be developing simplified assessment tools that will allow land stewards to evaluate the cost-effectiveness of future habitat restorations."
In 2000, the economic value of insect-pollinated crops in the United States was estimated at $18.9 billion.
Kremen, Winfree, Williams and Mace Vaughan, pollinator program director of the Xerces Society for Invertebrate Conservation, were among the specialists sharing their expertise at the 59th annual Entomological Society of America's meeting, held Nov. 13-16 in the Reno-Sparks Convention Center.
At one of the ESA seminars, Winfrey said that about 75 percent of the nation's crops require pollination, and that there are 20,000 species of native bees.
Kremen pointed out that "35 percent of the food we eat is pollinated by bees."
Vaughan, in emphazing the need to protect the pollinators, announced the Xerces Society's newest publication, Attracting Native Pollinators: Protecting North America's Bees and Butterflies.
To attract native pollinators, the Xerces Society says that we need to:
--Ensure pollination in our gardens, orchards or farms.
--Identify the flower-visiting insects of our region.
--Provide host plants and nesting sites for bees and butterflies.
--Create a landscape that is beautiful, diverse and pollinator friendly.
Good advice. We all have a role to fulfill in attracting and protecting the pollinators.
- Author: Kathy Keatley Garvey
We often hear of "cream of the crop," but the honey bee is the "queen of the crops."
Honey bees are crucial to
Can you name a fruit or nut crop that absolutely depends on honey-bee pollination? So much so that no commerical crop could be produced without cross pollination? No, not tomatoes! Here are some: almond, avocado, apple (most varieties), apricot (some varieties), cherry, chestnut, lychee fruit, peach (some varieties), pear (some varieties) plum, pomegranate, prune, sunflower, tangelo and tangerine.
- Author: Kathy Keatley Garvey
What are insect pollinators worth to the global economy?
Well, it's a lot less than the Wall Street bailout...er...rescue plan.
Recent research published in the journal Ecological Economics reveals just how important insect pollinators are.
A Eureka Alert press release issued by the Helmholtz Association of German Research Centres says that a team of French and German scientists found that the "worldwide economic value of the pollination service provided by insect pollinators, bees mainly, was $153 billion in 2005 for the main crops that feed the world."
That amounts to 9.5 percent of the total value of the world agricultural food production.
The study says that fruit and vegetables account for about a third of that total. The bee shortage has already hurt growers and consumers worldwide. Pollinator disappearance "would translate into a consumer surplus loss estimated between $190 to $310 billion," the news release says.
A Sept. 26 article in Business Week noted that "California almond growers, who require 1.5 million bee colonies for pollination, are renting hives for $200 each, up from $35 two years ago. In China, where pesticide overuse has killed off pollinators in some fruit orchards, farm workers have resorted to dabbing pollen into blooms by hand."
California's growing almond acreage, which now exceeds 700,000, requires two hives per acre. Our state does not have enough bees to pollinate the almonds, so bees are trucked in all over.
Honey bee researchers think that stress may be one of the factors in the declining bee population. Other factors: malnutrition, diseases, pesticides, parasites and changing climates.
Colony collapse disorder, a phenomonon characterized by bees mysteriously abandoning their hives, is probably due to those multiple factors, according to UC Davis apiculturist Eric Mussen.
The declining bee population, the growing need for pollination, and the burgeoning U.S. financial crisis--those issues should concern us all.
- Author: Kathy Keatley Garvey
If you love pomegranates, you can thank a honey bee.
If you love capturing images of pomegranates, you can thank a honey bee.
And, if you love juicing them and making pomegranate jelly—as I do—you can thank a honey bee.
The honey bee makes it all possible.
In mid-May, our 81-year old pomegranate tree blossomed. The silky red blossoms drew dozens of bees. On May 26, armed with a macro lens, I photographed them gathering nectar and pollen.
The blossoms, like the bees, quickly vanished. Worker bees live only four to six weeks during the busy season. The blossoms dropped and fruit formed. Today, four months later, the harvest-ready fruit glistens with red jewels. More photo ops!
The tree is truly amazing. It's 81 years old and yields six to seven orchard boxes of fruit each year. How can we be certain of its age? It was planted in 1927, the same year our Spanish stucco home was built. The owners planted a pomegranate tree because “our daughter loved them.”
So do the bees.