- Author: Kara Manke, kjmanke@berkeley.edu, (510) 643-7741
Berkeley — With a body the size of a fist and wings that span more than a foot, the big brown bat must gorge on 6,000 to 8,000 bugs a night to maintain its stature. This mighty appetite can be a boon to farmers battling crop-eating pests.
But few types of bats live on American farms. That's because the current practice of monoculture – dedicating large swathes of land to a single crop – doesn't give the bats many places to land or to nest.
Diversifying working lands – including farmland, rangeland and forests – may be key to preserving biodiversity in the face of climate change, says a new review paper published this week in Science by conservation biologists at the University of California, Berkeley.
Diversification could be as simple as adding trees or hedgerows along the edges of fields, giving animals like birds, bats and insects places to live, or as complex as incorporating a patchwork of fields, orchards, pasture and flowers into a single working farm.
These changes could extend the habitat of critters like bats, but also much larger creatures like bears, elk and other wildlife, outside the boundaries of parks and other protected areas, while creating more sustainable, and potentially more productive, working lands.
“Protected areas are extremely important, but we can't rely on those on their own to prevent the pending sixth mass extinction,” said study co-author Adina Merenlender, a UC Cooperative Extension Specialist in the Department of Environmental Science, Policy and Management at UC Berkeley. “This is even more true in the face of climate change, because species will need to move around to adapt to shifts in temperature and climate.”
A win-win for wildlife and for farms
Maintaining even small pieces of the original landscape – even a single tree– can help conserve the original diversity of species, Merenlender said. Clearing oak woodlands and shrublands to establish large vineyards hits many native species hard. Animals that are well adapted to urban and agricultural areas, such as mockingbirds, house finches and free-tail bats, continue to flourish, while animals that are more sensitive to disturbance, like acorn woodpeckers, orange-crowned warblers and big brown bats, begin to drop away. “If you can leave shrubs, trees and flowering plants, the habitat suitability -- not just for sensitive birds but also for other vertebrates – goes way up,” Merenlender said. This is true not only in California's vineyards, but on working lands around the world.
Incorporating natural vegetation makes the farm more hospitable to more creatures, while reducing the use of environmentally degrading chemicals like herbicides, pesticides and man-made fertilizer.
The ideal farming landscape includes woodland pastures and vegetable plots bumping up against orchards and small fields, said Claire Kremen, a professor in the Department of Environmental Science, Policy and Management. Integrating livestock produces manure which can fertilize the crops, while those same crops produce feed for livestock. Birds and bats provide pest control, and bees boost crop production by pollinating plants.
“It is possible for these working landscapes to support biodiversity but also be productive and profitable,” Kremen said. “And ultimately, this is where we have to go. We just can't keep mining our soils for their fertility and polluting our streams – in the end, this will diminish our capacity to continue producing the food that we need. Instead, we must pay attention to the species, from microbes to mammals, that supply us with critical services, like pollination, pest control and nutrient cycling”
“We have some amazing diversified farms, sustainably managed forests and species-rich rangelands here in California that exemplify working lands for conservation around the world,” Merenlender said. “We are calling for a scaling up of this approach around the world, and to do that we champion community-based action and more supportive polices” Kremen concludes.
RELATED INFORMATION
CONTACTS
Claire Kremen, ckremen@berkeley.edu, 510-367-2100 (cell)
Adina Merenlender, adinam@berkeley.edu, (707) 489-4362
- Author: Kathy Keatley Garvey
The event, open to the public, is set from 8 a.m. to 6 p.m. Saturday, May 7 in the UC Davis Conference Center on Alumni Lane. It will be hosted by the Honey and Pollination Center of the Robert Mondavi Institute for Wine and Food Science, and the UC Davis Department of Entomology and Nematology.
Keynoting the symposium will be Yves Le Conte, director, French National Bee Lab, Avignon, France; and Dennis vanEngelsdorp, assistant professor of entomology at the University of Maryland and project director for the Bee Informed Partnership.
Among the highlights:
9 a.m. Amina Harris, director of the Honey and Pollination Center, and Neal Williams, associate professor of the Department of Entomology and Nematology and the center's co-faculty director, will welcome the crowd and introduce the speakers.
9:15 a.m. Yves Le Conte will speak on "Honey Bees that Survive Varroa Mite in the World: What Can We Learn from the French Bees"
10:15: Rachel Vannette will discuss "How Microbial Communities in Floral Nectar Influence Pollinator Preference and Foraging"
11:15: Claire Kremen will cover "Rediversifying Intensive Agricultural Landscapes to Promote Native Pollinators."
1:30 p.m.: Dennis van Engelsdorp will speak on "Reducing Colony Losses: Does It Take a Village?"
2:15 p.m.: Lightning Round Talks: Six-minute presentations about many different programs in the world of beekeeping
3:30 p.m.: Brian Johnson will discuss "The Importance of Division of Labor for Understanding Colony Health."
4 p.m.: Quinn McFrederick will speak on "The Bee Microblome."
In addition, a graduate student poster display and competition will take place, with the winners announced at 4:30 p.m. First place is $1000; second, $750; third, $500, and fourth, $250. A closing reception follows at 4:45 in the Good Life Garden at the Robert Mondavi Institute for Wine and Food Science on Old Davis Road.
To register, access the Honey and Pollination Center website or for more information, contact Amina Harris at aharris@ucdavis.edu or (530) 754-9301.
Harris promises a rewarding and educational symposium. Comments from last year's symposium included:
- "As a new beehive owner I thought the information presented was fascinating and presented in a very efficient manner. I loved every aspect of the presentations!"
- "Nice to get science, there is a lot of fuzzy thinking out there."
- "Thank you for a well-organized, thoroughly engaging and thought-provoking day."
The UC Davis Conference Center is located across from the Mondavi Center for the Performing Arts.
![A honey bee foraging on a blanket flower, Gaillardia. (Photo by Kathy Keatley Garvey) A honey bee foraging on a blanket flower, Gaillardia. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/35903.jpg)
![An Italian honey bee dusted with pollen. It is foraging on an Iceland poppy. (Photo by Kathy Keatley Garvey) An Italian honey bee dusted with pollen. It is foraging on an Iceland poppy. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/35904.jpg)
- Author: Kathy Keatley Garvey
The wild bee research co-authored by 58 bee scientists and published today (June 16) in Nature Communications is drawing a lot of attention--and well it should.
Pointing out that wild bee diversity is declining worldwide at unprecedented rates, the researchers said steps must be taken to conserve them--and not just those that are the main pollinators of agricultural crops.
"This study provides important support for the role of wild bees to crop pollination through a comprehensive global summary,” said co-author and pollination ecologist Neal Williams, associate professor in the UC Davis Department of Entomology and Nematology. “At the same time, we found that in any one region, much of the pollination services from wild bees to a given crop come from just a few species, thus we need to be careful about using a simplistic economic ecosystem-services argument for biodiversity conservation and maintain actions that target biodiversity as specific goal. "
The study, led by David Kleijn of Wageningen University, The Netherlands, found that of the almost 80 percent of crop pollination provided solely by wild bees, only 2 percent are by the most common species. This indicates that the benefits of conserving only economically important organisms are not the same as the benefits of conserving a broad diversity of species, the researchers said.
The paper, “Delivery of Crop Pollination Services is an Insufficient Argument for Wild Pollinator Conservation,” is online at http://www.nature.com/naturecommunications. Among the co-authors are native pollinator specialist Robbin Thorp, distinguished emeritus professor of entomology at UC Davis, and conservation biologist Claire Kremen of UC Berkeley, a longtime associate of the UC Davis Department of Entomology and Nematology.
Wrote the researchers in their abstract: “There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation. However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops.”
“Dominant crop pollinators,” they pointed out, “persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments.”
The researchers analyzed data from more than 90 studies on five continents, including Europe and North America. They concluded that the higher levels of biodiversity provide greater benefits to the functioning and stability of ecosystems, with some functions also being “economically beneficial” for humans.
Kleijn and his colleagues studied 785 species, analyzing which provide the best economic returns from crop pollination. They found that wild bee communities contribute an average of more than $3,251 per hectare (2.471 acres) to the production of crops, and that they provide the same economic contributions as managed honey bee colonies. However, they also noted that the majority of crop pollination services provided by wild bees are accomplished by only a small subset of the most common species.
“Across the 90 studies, we collected a total of 73,649 individual bees of 785 species visiting crop flowers,” the authors wrote. “Although is an impressive number, it represents only 12.6 percent of the currently known number of species occurring in the states or countries where our studies took place. When we consider only bee species that contribute 5 percent or more to the relative visitation rate of any single study, the percentage drops to 3 percent of the species in the regional species pool. Yet these 2 percent of species account for almost 80 percent of all crop visits.”
These results suggest that conservation efforts targeted directly at a few species providing the majority of ecosystem services, such as crop pollination, would represent a good strategy if the goal is to improve economic returns. However, they said such a strategy is unlikely to be compatible with conserving threatened species and biological diversity “if the goal is to improve the functioning and stability of ecosystems.”
Williams worked with Kleijn and Winfree of Rutgers University New Brunswick, N.J., to conceive of some of the approaches used, particularly suggested looking at the abundance distributions of crop bees within the larger species pools of the region to understand whether the most important crop pollinators species are simply the common bees overall. Williams and Kremen also contributed to the manuscript, from the early drafts to the final versions.
As an aside, we certainly hope that this global research packs a social media wallop and leads to efforts to protect and preserve our wild bees. Unfortunately, many people never think about wild bees. It's "out of sight, out of mind," not "absence makes the heart grow fonder."
We'd all do well to take a look at the amazing macro bee images by Sam Droege, head 'of the bee inventory and monitoring program at the U.S. Geological Survey (USGS). His work has been featured in publications all over the world. Among the latest: National Geographic. See his USGS work posted on Flickr. And check out his book, An Up-Close Look at Pollinators Around the World, co-authored by Laurence Packer.
Absence CAN make the heart grow fonder...
![This macro image of a Ceratina bee is the work of Sam Droege of the bee inventory and monitoring program, the U.S. Geological Survey. This image is part of the public domain. This macro image of a Ceratina bee is the work of Sam Droege of the bee inventory and monitoring program, the U.S. Geological Survey. This image is part of the public domain.](/blogs/blogcore/blogfiles/30235.jpg)
![This is a female sweat bee, genus Lasioglossum, on a rock purslane. (Photo by Kathy Keatley Garvey) This is a female sweat bee, genus Lasioglossum, on a rock purslane. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/30236.jpg)
![A yellow-faced bumble bee, Bombus vosnesenskii, heads for a California golden poppy. (Photo by Kathy Keatley Garvey) A yellow-faced bumble bee, Bombus vosnesenskii, heads for a California golden poppy. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/30237.jpg)
- Author: Kathy Keatley Garvey
Wild bee diversity is declining worldwide at unprecedented rates, and steps must be taken to conserve them--and not just those that are the main pollinators of agricultural crops, agreed 58 bee researchers in a study published today (June 16) in Nature Communications, an open-access journal based in London.
"This study provides important support for the role of wild bees to crop pollination through a comprehensive global summary,” said co-author and pollination ecologist Neal Williams, associate professor in the UC Davis Department of Entomology and Nematology. “At the same time, we found that in any one region, much of the pollination services from wild bees to a given crop come from just a few species, thus we need to be careful about using a simplistic economic ecosystem-services argument for biodiversity conservation and maintain actions that target biodiversity as specific goal. "
Wild bees, or non-managed bees, include bumble bees (genus Bombus), sweat bees (genus Lasioglossum) and small carpenter bees (genus Ceratina).
The study, led by David Kleijn of Wageningen University, The Netherlands, found that of the almost 80 percent of crop pollination provided solely by wild bees, only 2 percent are by the most common species. This indicates that the benefits of conserving only economically important organisms are not the same as the benefits of conserving a broad diversity of species, the researchers said.
The paper, “Delivery of Crop Pollination Services is an Insufficient Argument for Wild Pollinator Conservation,” is online at http://www.nature.com/naturecommunications. Among the co-authors are native pollinator specialist Robbin Thorp, distinguished emeritus professor of entomology at UC Davis, and conservation biologist Claire Kremen of UC Berkeley, a longtime associate of the UC Davis Department of Entomology and Nematology.
“My role in this paper was through my collaborations with Neal Williams and Claire Kremen in their research projects on crop pollination by native bees,” Thorp said. “My identifications of the bees they sampled, provided the raw data for the calculations performed on the diversity and abundances of the bees pollinating the crops they studied.”
“There is compelling evidence that more diverse ecosystems deliver greater benefits to people, and these ecosystem services have become a key argument for biodiversity conservation,” the researchers wrote in their abstract. “However, it is unclear how much biodiversity is needed to deliver ecosystem services in a cost-effective way. Here we show that, while the contribution of wild bees to crop production is significant, service delivery is restricted to a limited subset of all known bee species. Across crops, years and biogeographical regions, crop-visiting wild bee communities are dominated by a small number of common species, and threatened species are rarely observed on crops.”
“Dominant crop pollinators,” they pointed out, “persist under agricultural expansion and many are easily enhanced by simple conservation measures, suggesting that cost-effective management strategies to promote crop pollination should target a different set of species than management strategies to promote threatened bees. Conserving the biological diversity of bees therefore requires more than just ecosystem-service-based arguments.”
The researchers analyzed data from more than 90 studies on five continents, including Europe and North America. They concluded that the higher levels of biodiversity provide greater benefits to the functioning and stability of ecosystems, with some functions also being “economically beneficial” for humans.
Kleijn and his colleagues studied 785 species, analyzing which provide the best economic returns from crop pollination. They found that wild bee communities contribute an average of more than $3,251 per hectare (2.471 acres) to the production of crops, and that they provide the same economic contributions as managed honey bee colonies. However, they also noted that the majority of crop pollination services provided by wild bees are accomplished by only a small subset of the most common species.
“Across the 90 studies, we collected a total of 73,649 individual bees of 785 species visiting crop flowers,” the authors wrote. “Although is an impressive number, it represents only 12.6 percent of the currently known number of species occurring in the states or countries where our studies took place. When we consider only bee species that contribute 5 percent or more to the relative visitation rate of any single study, the percentage drops to 3 percent of the species in the regional species pool. Yet these 2 percent of species account for almost 80 percent of all crop visits.”
These results suggest that conservation efforts targeted directly at a few species providing the majority of ecosystem services, such as crop pollination, would represent a good strategy if the goal is to improve economic returns. However, they said such a strategy is unlikely to be compatible with conserving threatened species and biological diversity “if the goal is to improve the functioning and stability of ecosystems.”
Williams worked with Kleijn and Winfree of Rutgers University New Brunswick, N.J., to conceive of some of the approaches used, particularly suggested looking at the abundance distributions of crop bees within the larger species pools of the region to understand whether the most important crop pollinators species are simply the common bees overall.
Williams and Kremen also contributed to the manuscript, from the early drafts to the final versions.
![Pollination ecologist Neal Williams working on bee research. (Photo by Kathy Keatley Garvey) Pollination ecologist Neal Williams working on bee research. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/30204.jpg)
![Native pollinator specialist Robbin Thorp, distinguished emeritus professor of entomology at UC Davis, identified the bees for the Williams/Kremen research. (Photo by Kathy Keatley Garvey) Native pollinator specialist Robbin Thorp, distinguished emeritus professor of entomology at UC Davis, identified the bees for the Williams/Kremen research. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/30216.jpg)
- Author: Kathy Keatley Garvey
Think of them as "the good guys" and "the good girls."
Insects such as lacewings, lady beetles and flower flies.
We're delighted to see that the Xerces Society for Invertebrate Conservation has just published a 250-page book on "Farming with Native Beneficial Insects."
The book advocates the use of beneficial insects to prey upon crop pests, thus "reducing or eliminating the use of pesticides," say co-authors Eric Lee-Mäder, Jennifer Hopwood, Mace Vaughan, Scott Hoffman Black, and Lora Morandin.
"This comprehensive guide describes how to recognize these insects and their habitat, and how to evaluate, design, and improve habitat for them," they write. They offer specific solutions, including native plant field borders, mass insectary plantings, hedgerows, cover crops, buffer strips, beetle banks, and brush piles.
The much-acclaimed book, available for purchase on the Xerces website, is drawing well deserved accolades, including this one from Claire Kremen, professor and co-director of the Berkeley Food Institute, University of California, Berkeley:
“If you are a grower or a backyard gardener, this is a ‘must have.' Readable and filled with gorgeous photos and handy charts, this book provides reams of information about how to get the upper hand on your pest issues with reduced or no pesticide use.”
Xerces officials say the release of Farming with Native Beneficial Insects coincides with its launch of a new nationwide workshop series on natural pest control: the Conservation Biological Control Short Course. The course, to begin in the West and Midwest, "provides farmers, crop consultants, and government farm agency staff with a comprehensive, hands-on training in the natural pest management strategies described in the book. A similar workshop model previously offered by Xerces trained tens of thousands of people in farm communities across the U.S. to conserve bees and restore pollinator habitat, and helped facilitate the restoration of more than 100,000 acres of wildflower habitat for bees."
Speaking of "the good guys" and "the good girls," be sure to read the UC Statewide Integrated Pest Management Project's website on beneficial insects and natural enemies. The natural enemies include assassin bugs, bigeyed bugs, brown lacewings, convergent lady beetles, damsel bugs, dustywings, syrphid flies and twicestabbed lady beetles.
What is Integrated Pest Management (IPM)? "Integrated pest management uses environmentally sound, yet effective, ways to keep pests from annoying you or damaging plants. IPM programs usually combine several pest control methods for long-term prevention and management of pest problems without harming you, your family, or the environment. Successful IPM begins with correct identification of the pest. Only then can you select the appropriate IPM methods and materials."
UC IPM points out:
- Many pests can be managed without the use of pesticides.
- Use pesticides only if nonchemical controls are ineffective and pests are reaching intolerable levels.
- Use pesticides in combination with the methods described above.
- Choose pesticides carefully. Use the least toxic, most effective material to protect human health and the environment.
- Examples of least toxic insecticides include:
- Soaps;
- Oils; and
- Microbials such as Bacillus thuringiensis (Bt) and spinosad.
The more we learn about pests and the natural enemies of pests, the oft-heard quote, "Keep your friends close and your enemies closer" rings quite true. The more we learn about our enemies, the less likely they will be able to harm us.
![A syrphid fly, aka flower fly or hover fly, nectaring on a tower of jewels. (Photo by Kathy Keatley Garvey) A syrphid fly, aka flower fly or hover fly, nectaring on a tower of jewels. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/23986.jpg)
![A lacewing glows in the afternoon sun. Larvae eat such soft-bodied insects as mealybugs, psyllids, thrips, mites, whiteflies, aphids, small caterpillars, leafhoppers, and insect eggs, according to the UC IPM website. (Photo by Kathy Keatley Garvey) A lacewing glows in the afternoon sun. Larvae eat such soft-bodied insects as mealybugs, psyllids, thrips, mites, whiteflies, aphids, small caterpillars, leafhoppers, and insect eggs, according to the UC IPM website. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/23987.jpg)
![The lady beetle, aka ladybug, is well known for its voracious appetite of aphids. (Photo by Kathy Keatley Garvey) The lady beetle, aka ladybug, is well known for its voracious appetite of aphids. (Photo by Kathy Keatley Garvey)](/blogs/blogcore/blogfiles/23988.jpg)