Posts Tagged: pollinators
Bee knowledgeable: Pollinator Week is June 19–25, 2017
Bees are the most important pollinators of California agriculture — helping farmers grow field crops, fruits, nuts, and vegetables. Honey bees receive most of the credit for crop pollination, but many other kinds of bees play an important role as well. There are 1600 species of bees in California! Take time during Pollinator Week to learn about the different kinds of bees and what you can do to help them flourish.
Why should I care about other kinds of bees?
Bees other than honey bees contribute significantly to crop pollination. For example, alfalfa pollination by alfalfa leafcutter bees is worth $7 billion per year in the United States. Other bees can also boost the result of honey bee pollination — in almond orchards, honey bees are more effective when orchard mason bees are present. The more bee species, the merrier the harvest.
While growers often rent honey bee colonies to pollinate their crops, some wild bees pollinate certain crops even better than honey bees do. For instance, bumble bees are more effective pollinators of tomato because they do something honey bees do not: they shake pollen out of flowers with a technique known as buzz pollination. Likewise, native squash bees are better pollinators of cucurbits — unlike honey bees, they start work earlier in the day, and males even sleep in flowers overnight.
How can I help honey bees and other bees?
When it comes to land management and pest management practices, some bees need more accommodations than others. That's why it is important to know what bees are present in your area and important to your crop, and plan for their needs. Use this bee monitoring guide to identify bees present on your farm.
You can help all kinds of bees by using integrated pest management (IPM). This means using nonchemical pest management methods (cultural, mechanical and biological control), monitoring for pests to determine whether a pesticide is needed, and choosing pesticides that are less toxic to bees whenever possible. Check out the UC IPM Bee Precaution Pesticide Ratings to learn about the risks different pesticides pose to honey bees and other bees, and follow the Best Management Practices To Protect Bees From Pesticides.
Bees also need plenty of food to stay healthy and abundant. Plant flowers that provide nectar and pollen throughout the year. See the planting resources below to find out which plants provide year-round food for specific types of bees.
Like honey bees, native bees need nesting areas to thrive. Bumble bees, squash bees, and other bees nest underground. Ground-nesting bees may require modified tilling practices (such as tilling fields no more than 6 inches deep for squash bees) or no-till management to survive. For above-ground nesters, like carpenter bees and mason bees, consider planting hedgerows or placing tunnel-filled wooden blocks around the field. See the habitat resources below for more information about native bee nesting in agricultural areas.
Bee habitat resources
- Habitat for Bees and Beneficials
- Managing Wild Bees for Crop Pollination
- Native Bee Nest Locations in Agricultural Landscapes
- Farming for Bees: Guidelines for Providing Native Bee Habitat on Farms
- Hedgerow Planting for Pollinators: Central Valley, Central Coast, Southern California
- Conservation Cover for Pollinators: Central Valley, Central Coast, Southern California
- The Integrated Crop Pollination Project: Tools for Growers
Sources
- Insect Pollinated Crops, Insect Pollinators and U.S. Agriculture: Trend Analysis of Aggregate Data for the Period 1992–2009.
- Native bees are a rich natural resource in urban California gardens. (PDF)
- Honey bees are more effective at pollinating almonds when other species of bees are present.
Twelve rules of thumb for creating a bee-friendly home landscape this fall
“Fall, with its cooler temperatures, shorter days, and imminent rainfall, is the best time to plant a bee garden in California. Much of the plants' growth at this time will be in the roots rather than the vegetative growth, and that gives new plants an advantage when temperatures warm up and the soil dries in the spring. Fall and winter are usually the wet seasons in California, and a bee garden will benefit from the natural pattern of rainfall that helps plants get established,” according to California Bee-Friendly Garden Recipes (Pawelek et al. 2015)
With fall being the perfect time for planting consider making your home landscape bee-friendly and follow UC Agriculture and Natural Resources' California Bee-Friendly Garden Recipes - 12 rules of thumb for creating a bee-friendly home landscape:
- Learn the seasonality of plants and bees.
Bees need both pollen and nectar resources from plants all year long. Sugary nectar provides energy for adult bees, and protein-rich pollen is used to feed their young. Plant not only a variety of plants (to ensure both pollen and nectar resources) but also make sure that they bloom at different times throughout the year, with the most active times of bees in garden running from February to October. - Provide a diversity of floral hosts.
A large variety of plants in a garden attracts a more diverse bee population. UC ANR researchers recommend planning a minimum of 20 different plant types to provide plenty of nectar and pollen sources for bees. If space or resources don't allow, consider plants that provide both nectar and pollen resources such as seaside daisy (Erigeron glaucus), blanketflower (Gaillardia x grandiflora), thyme (Thymus vulgaris), and coneflower (Echinacea purpurea). - Give structure to the garden.
When planning your garden arrange plants so it is easy to observe the bees that are visiting your landscape. Place taller plants or shrubs in the back and smaller or shorter plants in the front. Or you can plant in the shape of an island to allow viewing from all sides. - Plant in the sun.
Typically bees prefer flowers in the sunshine over the shade. Monitor the amount and location of sun in your home landscape and plant sun-loving bee-attractive plants in the sunniest section of your yard. - Plant shrubs, perennials and annuals in patches.
Most bees will visit one type or a few types of flowers each time they forage, an abundance of the same flower variety allows for more efficient foraging for bees. The California Bee-Friendly Garden Recipes publication recommends a 3.5 ft x 3.5 ft flower patch of the same variety. - Don't forget to seed annuals.
Plant seeds for spring blooming annuals and bulbs in the fall and take advantage of the winter rains and provide beautiful flowers in the spring. Great options include sunflowers (Helianthus annuus), Mexican sunflower (Tithonia diversifolia), California poppy (Eschscholzia californica), and zinnia (Zinnia elegans). - Maintain flowers.
Prolong a plant's blooming season by dead-heading. As soon as flowers begin to fade, wither and brown, pinch or cut-off the flower stem below the flower or right above the first set of healthy leaves. This allows the plant to continue to invest in producing more blooms and not seeds. - Create a watering regimen.
Regular watering of plants during blooming season allows plants to produce more flowers for a longer period of time. If a plant is water stressed it won't produce new flowers and nectar and pollen production declines. Consider plants that thrive in California's dry Mediterranean climate, UC Berkeley's Urban Bee Lab offers a list of the best bee plants with a large selection of California native options. - Do not use pesticides!
Applying pesticides to your home landscape can kill beneficial insects and bugs visiting your garden, including bees. Consider using integrated pest management practices that are natural or organic methods like hand-picking, spraying with water or natural insecticides. Contact your local UCCE Master Gardener Program to learn more about integrated pest management. - Consider plant climate zones.
Consider right plant, right place when selecting plants for your home landscape. Most gardening books, websites, plant labels and seed packets refer to a plants hardiness zone, climate zone or growing zone. Become familiar with the climate or microclimate in your area, the USDA Plant Hardiness Map and the Sunset Zone Map are a great starting guide for determining what plants will thrive in your garden space. - Provide homes for nesting bees.
A bee-friendly garden provides cover and a safe place for bees to raise young. Most bee habitats are either in the ground or in pre-existing cavities. Provide a nesting home for bees in your garden by leaving a small section of your landscape unmulched for ground-nesting bees. Nesting blocks, drilled holes in untreated wood or “bee-condos” can be offered to bees that prefer a pre-existing cavity habitat. - Provide nesting materials, including a water source.
Bees build their nests with mud, plant leaves and resins. Bees require a water source to not only drink but also to make mud for nest building. Fill a shallow water dish or birdbath to your garden, add small rocks or a floating cork for bees to rest and to prevent drowning.
Learn more with UC ANR and the UC Master Gardener Program
Interested in learning more about how to grow a buzzing bee-friendly garden? The UC Master Gardener Program has University trained volunteers who are eager to help. Volunteers are available to answer questions about preparing your soil, plant selection, pest management, and more. With local programs based in more than 50 counties across California and thousands of workshops a year there is sure to be an event or class near you. Visit our website to find your local UC Master Gardener Program, mg.ucanr.edu.
Resources:
Pawelek, Jaime C., Frankie, Gordon W., Frey, Kate, Leon Guerrero, Sara, and Schindler, Mary. 2015. “California Bee Friendly Garden Recipes.” ANR Publication 8518, http://anrcatalog.ucanr.edu/pdf/8518.pdf
Ponder, Marissa, Frankie, Gordon W., Elkins, Rachel, Frey, Kate, Coville, Rollin, Schindler, Mary, Pawelek, Jaime, and Shaffer, Carolyn. 2013. “How to Attract and Maintain Pollinators in your Garden.” ANR Publication 8518, http://anrcatalog.ucanr.edu/pdf/8498.pdf
UC Berkeley Urban Bee Lab, www.helpabee.org
Pollinator partnership, www.pollinator.org
To bee or not to bee depends on the crop
About 35 percent of the food we eat depends on the assistance of bees to pollinate plants and trees so they will produce fruit, nuts or vegetables. It takes 1.6 million colonies of honey bees to pollinate California's 800,000 acres of almond trees.
Our food choices would be dramatically reduced if bees weren't around to pollinate. To illustrate what the produce section of a grocery store would look like in a world without bees, Whole Foods Market removed the products that depend on pollination from one of its stores and took a photo. See the difference: http://ucanr.tumblr.com/post/84164840510/kqedscience-whole-foods-shows-customers-the. Without bees, more than half the fruits and vegetables were eliminated.
Honey bees and other pollinators are being threatened by the drought, disease, mites, loss of habitat and food sources, according to Eric Mussen, UC Cooperative Extension specialist in the Department of Entomology at UC Davis and bee expert.
Beth Grafton-Cardwell, UC Cooperative Extension specialist in the Department of Entomology at UC Riverside and director of Lindcove Research and Extension Center, talks about the role of pollinators in California agriculture in this video: http://www.youtube.com/watch?v=8suOt5PnzWc&feature=youtu.be.
To see photos of different kinds of pollinators and to learn more about how to help them thrive, visit our pollinator page. On May 8, help count the pollinators in your community and add them to the map at http://beascientist.ucanr.edu.
Pollinators in trouble
“I'll be holding a precious resource in my hands, one that is essential to life on earth,” says Allen-Diaz. “I'll be placing my hands in Norm's hands to raise awareness about the value of honeybees.”
While raising money for education is certainly a worthy goal, as Allen-Diaz says, the event also draws attention to the plight of our most important agricultural pollinator. In 2006, a number of beekeepers in the Western U.S. noticed their hives had lost 30 to 70 percent of their worker bees. The phenomenon, now known as colony collapse disorder (CCD), is still not fully understood, though a number of factors are believed to be involved. They include habitat loss or degradation and fragmentation, poor nutrition, certain bee management and agricultural practices, natural and chemical toxins, diseases, and parasites. Any one of these factors can affect the insects' ability to combat any of the others. Isolating a single cause, if there is one, has proved elusive.
Many of the fruits and vegetables on the tables of the world are pollinated by insects, particularly bees, and if they were to disappear, our sources of plant food would be restricted to grains and not too much else. It's no wonder CCD is such a concern (for example, see the United Nations Environmental Program 2010 report on Global Bee Colony Disorder and USDA, Honey Bees and Colony Collapse Disorder.
As human population grows and becomes more urban, and as habitats get more fragmented, it is no longer adequate to focus conservation efforts merely in non-urban, non-working landscapes.
“We need to figure out how to accommodate as many native species as possible in these kinds of places,” says Patrick Huber of the City of Davis Open Space and Habitat Commission, which has adopted pollinator habitat enhancement as a working goal. The Commission is working to compile a GIS dataset of known big patches of habitat in Davis, in order map pollinator resources around town.
Huber is a geographer in the Landscape Analysis and Systems Research lab at UC Davis, where he focuses on spatial scale in conservation planning. He is working on a tool to help match gardeners with plants that will grow well in their regions, that are locally available, and that provide a network of resources for pollinators throughout the urban landscape and on into the agricultural landscape. For the moment this project is being piloted in Davis, but the hope is to expand it to other communities, tying in resources such as CalFlora.
- Planning for succession blooming (in the Central Valley, that means late winter through fall)
- Putting plants in clumps at least 4 feet long if possible (honeybees, especially, like to specialize)
- Putting in plants that provide both nectar and pollen (nectar is fuel for adult bees, pollen is protein for the young)
- Using native plants where possible; they're drought tolerant and have what our native bees need
- Avoiding most-toxic pesticides and herbicides
- Providing a clean source of water (a slow-dripping tap on a sloped surface is ideal; bees like to drink from very shallow sources)
- Providing cavity nest holes in wood for carpenter and other bees
- Leaving some areas of gardens unmulched for ground-nesting bees
There are ways the agricultural landscape can be made more hospitable, too. Neal Williams, professor of entomology at UC Davis, has been working on a project to install 600- to 800-meter plots of flowering plants alongside large fields as resources for pollinators. This has moved out of the trial phase into test plots in coastal and foothill areas as well as in the Central Valley.
Meanwhile, we can all help count our pollinators on May 8, the Day of Science and Service to celebrate 100 years of Cooperative Extension in California. We'll be conducting our own pollinator count here outside the ANR building in Davis: join us, or let us know about yours!
Many thanks to Kathy Keatley Garvey for use of her photos.
Honey bees: Should they be banned from native plant restoration areas?
The dwindling resources of pollen and nectar-producing plants in California greatly concern bee scientists and beekeepers, and rightfully so.
But the dwindling resources also greatly concern native pollinator specialists and native plant enthusiasts. Some worry that honey bees, which are non-natives, may be "reducing" or "eliminating" native pollinators through competition for food.
Are they?
Extension apiculturist Eric Mussen of the UC Davis Department of Entomology and Nematology explains that a number of agencies and organizations are cooperating in an effort to "restore" regions of the California Central Valley to their "original state."
“The major emphases are (1) replacing non-native vegetation with native plants and (2) encouraging native animals to return to their former ranges,” Mussen says. "The result has been eviction of beekeepers from apiary locations that have been used for decades as seasonal spots for rebuilding populations following the stresses of commercial pollination or for producing honey."
Indeed, in some situations, honey bees can survive, and native pollinators can’t.
“With honey bees, if we provide them with an adequate hive and food sources, they are likely to survive,” Mussen says. “However, native pollinators can be very particular about the environment in which they can exist. If their nesting habitat is disturbed, modified or destroyed, they cannot live in the area, despite an abundance of food plants. In many California locations, it is habitat alteration or destruction, not lack of food, which eliminated the native pollinators.”
So, should honey bees be banned from restoration areas?
"No," Mussen says. "Honey bees should be solicited for restoration areas, not banned."
Mussen shares a list of 130 native California plants that are likely to be visited - "and probably pollinated" - by honey bees. They include button bush or button willow, fiddleneck, and California golden poppy. The list is excerpted from Nectar and Pollen Plants of California by G. H. Vansell UC Berkeley, plus personal observations by native pollinator specialist Robbin Thorp, UC Davis emeritus professor of entomology. The list is updated, reflecting information on the CalFlora website and the Jepson Manual of Higher Plants of California.
Thorp, who monitors the Häagen-Dazs Honey Bee Haven, planted in the fall of 2009 on Bee Biology Road, UC Davis, has found more than 80 different species of bees - and counting - in the half-acre bee garden. It's located next to the apiary at the Harry H. Laidlaw Jr. Honey Bee Research Facility.
So honey bees and native bees share the resources.
A honey bee foraging on button willow, also known as button bush, Cephalanthus occidentalis. Honey bees on non-natives, and the button bush is a native California plant. (Photo by Kathy Keatley Garvey)
Honey bee visiting California golden poppy, Eschscholzia spp. (Photo by Kathy Keatley Garvey)
Honey bee foraging on fiddleneck, Amsinckia spp. (Photo by Kathy Keatley Garvey)