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Posts Tagged: Xerces Society

Robbing Nectar

We all take short cuts--short cuts around the campus, to the beach, to a favorite restaurant...

Honey bees take short cuts, too.

We've often watched assorted bumble bees and carpenter bees drill a hole in a long-tubed flower to rob the nectar.

And we've watched honey bees benefitting from this behavior.

Today we observed a carpenter bee, Xylocopa tabaniformis orpifex, engaging in nectar robbing in salvia at the UC Davis Arboretum.  Nectar robbing occurs when a bee or other animal circumvents the usual plant-pollinator relationship and "cheats" by entering a flower from the outside to steal nectar, thus avoiding pollination or contact with the anthers.

There's excellent information on bumble bees, their habitat needs, their behavior, and identifying characteristics in a free, downloadable PDF from the Xerces Society for Invertebrate Conservation: "Conserving Bumble Bees: Guidelines for Creating and Managing Habitat for America's Declining Pollinators."

The PDF mentions that "short-tongued bumble bees will engage in 'nectar robbing' from flowers with a long corolla tube by biting holes at the base of the corolla and drinking the nectar from the outside of the flower." The bee grabs the reward but doesn't contribute to "the plant's pollination needs."

Carpenter bee, Xylocopa  tabaniformis orpifex, robbing nectar from salvia. (Photo by Kathy Keatley Garvey)
Carpenter bee, Xylocopa tabaniformis orpifex, robbing nectar from salvia. (Photo by Kathy Keatley Garvey)

Carpenter bee, Xylocopa tabaniformis orpifex, robbing nectar from salvia. (Photo by Kathy Keatley Garvey)

Honey bee gathering nectar from a carpenter bee's pierced hole in the long tube of a salvia.  (Photo by Kathy Keatley Garvey)
Honey bee gathering nectar from a carpenter bee's pierced hole in the long tube of a salvia. (Photo by Kathy Keatley Garvey)

Honey bee gathering nectar from a carpenter bee's pierced hole in the long tube of a salvia. (Photo by Kathy Keatley Garvey)

Another honey bee reaping the benefits of nectar robbing by a carpenter bee. (Photo by Kathy Keatley Garvey)
Another honey bee reaping the benefits of nectar robbing by a carpenter bee. (Photo by Kathy Keatley Garvey)

Another honey bee reaping the benefits of nectar robbing by a carpenter bee. (Photo by Kathy Keatley Garvey)

Posted on Friday, May 3, 2013 at 9:58 PM

Saving the Rusty-Patched Bumble Bee

It's good to see that the Xerces Society for Invertebrate Conservation and noted bumble bee expert Robbin Thorp of UC Davis have filed a petition with the U.S. Fish and Wildlife Service for Endangered Species Act protection for the beleagured rusty-patched bumble bee.

They previously filed a petition to save Franklin's bumble bee, a bumble bee known to inhabit a small area of southern Oregon and northern California. Thorp has been monitoring Franklin's bumble bee (Bombus franklini) since 1998 but hasn't seen it since August 2006 when he detected one at Mt. Ashland.

In a recent press release, the Xerces Society related that the rusty-patched bumble bee, (Bombus affinis), "has disappeared from 87 percent of its historic range (which once included 25 states). Where it is still found, this bee is much less abundant than it was in the past."

 “The charismatic and once common rusty patched bumble bee has suffered severe and widespread declines throughout its range in the eastern U.S. since 1997," Thorp said. "The few scattered recent sightings thanks to intensive searches are encouraging, but the species is in critical need of federal protection.”

Why has the population of the rusty-patched bumble bee declined? Good question, and one with no fully determined answer, according to Thorp and Sarina Jepsen, the Xerces Society's endangered species program director.

"However, in related bumble bees that also are declining, researchers at the University of Illinois have recently found higher levels of a fungal pathogen and lower levels of genetic diversity," Jepson wrote in a press release. "Notably, the rusty-patched bumble bee was too scarce in the landscape to be included in these analyses."

"The leading hypothesis," Jepson says, "suggests that this fungal pathogen was introduced from Europe by the commercial bumble bee industry in the early 1990s, and then spread to wild pollinators. Although it has not been proven, the hypothesis is supported by the timing, speed and severity of the decline—a crash in laboratory populations of bumble bees occurred shortly before researchers noticed a number of species of formerly common bumble bees disappearing from the wild."

Meanwhile, we hope that Bombus affinis doesn't go the way of Bombus franklini.

As the Xerces Society's press release points out: "Pollinators are critical components of our environment and essential to our food security—providing the indispensable service of pollination to more than 85 percent of flowering plants and contributing to one in three bites of the food that we eat. Bumble bees are among the most widely recognized and well understood group of native pollinators in North America and contribute to the pollination of food crops such as squash, melon, blueberry, cranberry, clover, greenhouse tomato and greenhouse pepper, as well as numerous wildflowers."

Read more about this bumble bee from the Xerces website. And why researchers call the declining bumble bee population "alarming."

The Xerces Society, an international organization founded in 1971 and headquartered in Portland, Ore., is a nonprofit organization that "protects wildlife through the conservation of invertebrates and their habitat" and "is at the forefront of invertebrate protection worldwide, harnessing the knowledge of scientists and the enthusiasm of citizens to implement conservation programs."

Native pollinator specialist Robbin Thorp of UC Davis is a nationally known expert on bumble bees. (Photo by Kathy Keatley Garvey)
Native pollinator specialist Robbin Thorp of UC Davis is a nationally known expert on bumble bees. (Photo by Kathy Keatley Garvey)

Native pollinator specialist Robbin Thorp of UC Davis is a nationally known expert on bumble bees. (Photo by Kathy Keatley Garvey)

This photo of the rusty-patched bumble bee is the 2012 work of Christy Stewart at the Pheasant Branch Conservancy in Wisconsin.
This photo of the rusty-patched bumble bee is the 2012 work of Christy Stewart at the Pheasant Branch Conservancy in Wisconsin.

his photo of the rusty-patched bumble bee is the 2012 work of Christy Stewart at the Pheasant Branch Conservancy in Wisconsin.

Posted on Tuesday, February 19, 2013 at 7:46 PM

The Importance of Pollinators

It's a brief appearance but the message is important.

Pollination ecologist Neal Williams, assistant professor of entomology at UC Davis, appears briefly in a segment on native pollinators produced by America's Heartland. The show is now airing throughout the country. (Watch video)

Reporter Sarah Gardner of America’s Heartland touches on the declining population of honey bees--which European colonists brought here in 1622--and native pollinators, which are also declining.

“Farmers, scientists and others in U.S. agriculture are mounting an effort to develop a unique pollinator partnership promoting the growth of native plants on farms, orchards and ranches all across America,” Gardner said.

Williams is quoted as saying: “In the East, native bees can potentially provide all the pollination that’s necessary in the vast majority of those farms.”

It's great to see the focus on pollinators!

Gardner interviewed Mace Vaughn of the Xerces Society for Invertebrate Conservation; Ernie Shea of the Native Pollinators in Agriculture Project; and A. G. Kawamura, former California Secretary of Agriculture, among others.

Vaughn said that  “unless we encourage native pollinators, consumers are going to see fewer food choices and higher prices. The conservationist is urging farmers and growers to add native plants to their growing areas in an effort to attract different bee species, butterflies, hummingbirds and other animals that can help in cross pollinating crops.”

Williams, who joined the UC Davis Department of Entomology in 2009, was a featured speaker at the International Symposium on Pollinator Conservation, held last January in Fukuoka, Japan. He explored agricultural landscape change and the role of bee life history in predicting and understanding responses of bee communities.

(Editor's Note: America's Heartland is airing the program beginning this week (Jan. 1-6) and it can also be seen on America's Heartland website. To learn when the program airs in your zip code, access this site.)

Pollination ecologist Neal Williams of UC Davis with native bees. (Photo by Kathy Keatley Garvey)
Pollination ecologist Neal Williams of UC Davis with native bees. (Photo by Kathy Keatley Garvey)

Pollination ecologist Neal Williams of UC Davis with native bees. (Photo by Kathy Keatley Garvey)

Posted on Thursday, January 3, 2013 at 8:19 PM

Not Your Average Garden-Variety Calendar

It's not your average garden variety calendar.

It's absolutely bee-utiful.

Native bees reign supreme in  “Garden Variety Native Bees of North America,” a calendar produced by University of California alumni as a benefit for two non-profit organizations.

The perpetual calendar, the work of native bee enthusiast Celeste Ets-Hokin and entomologist/photographer Rollin Coville, both of the Bay Area, features native bees found throughout North America, including the leafcutter bee, bumble bee and sweat bee.

The macro photography is simply stunning. Through these photos, you can get up close and personal with bees you may never have even noticed. The ultra green sweat bees are especially spectacular.

Native pollinator specialist Robbin Thorp, emeritus professor of entomology at UC Davis, provided “considerable insight into the biology and ecology of several native bee genera,” said Ets-Hokin.

Also contributing extensively were UC Berkeley faculty members Gordon Frankie and Claire Kremen. Frankie shared his extensive knowledge of native bees in urban gardens. Kremen provided crucial information on native bee crop pollination services, based on her studies in Yolo County.

A portion of the proceeds will benefit the Great Sunflower Project, a national pollinator monitoring and conservation program based in San Francisco, and the Portland, Ore-based Xerces Society for Invertebrate Conservation, which protects native bees and their habitat throughout the United States.

Each native bee comes complete with information, such as the genus, common name, pollen/nectar sources, emergence time, nesting habit, and distinguishing characteristics.

For instance, you'll learn that bumble bees are excellent crop pollinators; they pollinate such crops as tomatoes, cranberries and blueberries better than honey bees.

You can attract bumble bees to your own garden by planting such pollen/nectar sources as giant hyssop (Agastache); manzanita (Arctostaphylos), ceanothus (Ceanothus); California poppy (Eschscholzia), sunflower (Helianthus); and beard tongue (Penstemon). 

It's all there--all there on the calendar.

Coville, who received his doctorate in entomology from UC Berkeley in 1978, has been photographing insects and spiders for more than 25 years. He is collaborating with Thorp and Frankie on a number of projects, including a book on urban bees. It's due out next year.

Ets-Hokin, a UC Berkeley zoology graduate, devotes her time to the public awareness and conservation of native bees. For the past several years, she has collaborated with the Alameda County Master Gardeners in establishing a native bee demonstration garden at Lake Merritt, Oakland.

Coville takes many of his images there and now he has Ets-Hokin hooked on photography.

Preview the calendar here. Want to order one or more? Go to the printer's website.

This is one of Rollin Coville's stunning photos of a male green sweat bee, Agapostemon. (Photo by Rollin Coville, used with permission),
This is one of Rollin Coville's stunning photos of a male green sweat bee, Agapostemon. (Photo by Rollin Coville, used with permission),

This is one of Rollin Coville's stunning photos of a male green sweat bee, Agapostemon. (Photo by Rollin Coville, used with permission),

The cover of the calendar,
The cover of the calendar, "Garden Variety Native Bees of North America." (Photos by Rollin Coville)

The cover of the calendar, "Garden Variety Native Bees of North America." (Photos by Rollin Coville)

Posted on Tuesday, November 29, 2011 at 8:14 PM

Protecting the Pollinators

Yellow-faced bumble bee, Bombus vosnesenskii. (Photo by Kathy Keatley Garvey)
It's good to see so many publications focusing on the pollinator crisis--because that's exactly what it is, a crisis.

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.

Assistant professor Neal Williams and Kimiora Ward, research associate from the Williams lab, collect bees.  (Photo by Kathy Keatley Garvey)
Assistant professor Neal Williams and Kimiora Ward, research associate from the Williams lab, collect bees. (Photo by Kathy Keatley Garvey)

Assistant professor Neal Williams and Kimiora Ward, research associate from the Williams lab, collect bees. (Photo by Kathy Keatley Garvey)

Neal Williams (right) and colleague Rufus Isaacs confer at the Entomological Society of America meeting Wednesday, Nov. 16 in Reno. (Photo by Kathy Keatley Garvey)
Neal Williams (right) and colleague Rufus Isaacs confer at the Entomological Society of America meeting Wednesday, Nov. 16 in Reno. (Photo by Kathy Keatley Garvey)

Neal Williams (right) and colleague Rufus Isaacs co confer at the Entomological Society of America meeting Wednesday, Nov. 16 in Reno. (Photo by Kathy Keatley Garvey)

Posted on Thursday, November 17, 2011 at 9:47 PM

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