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Celebrating Pollinators: Without This Tiny Fly, You’d Have No Chocolate...
Let me tell you ’bout the birds and the bees, and a lot of others: One out of every three mouthfuls of food we eat is delivered by pollinators.
by Denise Cowie - 6/24/2007
Did you know that the world’s supply of chocolate – chocolate! – depends on a tiny fly the size of a pinhead?
Chocolate, as most of us know, comes from cacao. And midges, tiny flies that live in damp, shady rainforests, are the only critters that can work their way through the complex cacao flower and pollinate it, according to some fun facts provided by the folks at www.pollinator.org.
They are spreading the word because this is International Pollinator Week.
Thanks to a proclamation by Secretary of Agriculture Mike Johanns, and a unanimous vote by the U.S. Senate, the week of June 24 to 30 marks a celebration of our pollinators, something that is destined to become an annual event.
Pollinators are serious business
That’s because this is more than just a cute bit of whimsy about birds, bees and butterflies. Taking care of our pollinators is serious business, and the more we’re all aware of that, the better. In order to bear fruit, three-quarters of all flowering plants – including most food crops and some that provide fiber, drugs, and fuel – rely on pollinators for fertilization, according to the National Academy of Science.
National Pollinator Week is a project of the North American Pollinator Protection Campaign (NAPPC), and it’s designed to publicize the importance of pollinators and to call on the public to take action to support pollinator health and abundance.
“National Pollinator Week will focus on promoting actions that help pollinators,” said Laurie Davies Adams, who manages NAPPC, before the week kicked off. “Through habitat destruction, misuse of pesticides, and pollution, humans have provoked a decline in many species of pollinators, which play an essential role in the reproduction of flowering plants both on farms and in the wild.”
Choosing native plants can help
Not just any old plant will do to keep pollinators happy. Like the cacao flower that is pollinated by that tiny fly, some plants depend on a specific pollinator species – and that pollinator depends on that specific type of plant for food. Pollinator and plant have become inter-dependent, like fig wasps and fig trees, or monarch butterflies and milkweed. If one disappears, so will the other.
That’s one reason native plants are important. Although the U.S. apparently lags behind Europe in collecting data on pollinator populations, the National Academy of Sciences has suggested that “landowners can take simple and relatively inexpensive steps to make habitats more ‘pollinator friendly’ … by growing native plants.”
Quoting some scary statistics
Professor Doug Tallamy made a similar point when he addressed the annual Native Plants in the Landscape Conference at Millersville University on June 8 (a conference for which Bartram’s Garden and the Mt. Cuba Center are co-sponsors).
Tallamy is chair of the Department of Entomology and Wildlife Ecology of the University of Delaware in Newark, and he knows his insects. He’s been studying their interaction with plants for years (his book, Bringing Nature Home, will be published by Timber Press this summer), and he quotes some scary figures on habitat loss and the impact of alien plant species.
“Insects that evolved in eastern North America cannot survive on plants from Europe or Asia,” he told the conference. But of the 1385 plant genera in the mid-Atlantic states, only 884 are natives.
Seeking 'Lepidoptera abundance'
Talking of “Lepidoptera abundance” [the prevalence of butterflies and moths, both pollinators], he said that there are 3,500 species of caterpillars in the mid-Atlantic.
Research had shown that “aliens supported 4.5 species on average, and natives supported more than 70 species on average,” he said, “which means that natives support more than 29 times as many caterpillars as aliens.”
Fewer caterpillars doesn’t only mean fewer butterflies and moths as pollinators, it means fewer birds, too, because birds eat the caterpillars.
Is there a solution?
What to do? Well, you could convert some of your lawns to pollinator-supporting gardens, creating corridors from one backyard habitat to another until you have a much larger habitat, as suggested by the National Wildlife Federation. And you can grow more native plants, especially trees and shrubs – which support greater numbers of insects than herbaceous perennials.
More important than planting native perennials, says Tallamy, is growing native shrubs and trees – because they support more species. Among the most valuable native woodies, he points out, an oak tree supports 517 Lepidoptera species, a willow supports 456, cherry and plum trees 448, birch 413, and so on. Non-native woodies simply cannot compete with those numbers. Nowhere near it.
Pollinator populations on decline
Last October, the National Academy of Science issued a report that said long-term population trends for some North American pollinators – bees, birds, bats, and other animals and insects that spread pollen so plant fertilization can occur – are “demonstrably downward.”
The report by the National Research Council said research indicates shortages of pollinators for agriculture already exist, and that decreases in wild pollinator populations could disrupt ecosystems in the future.
“Despite its apparent lack of marquee appeal, a decline in pollinator populations is one form of global change that actually has credible potential to alter the shape and structure of terrestrial ecosystems,” said committee chair May R. Berenbaum of the University of Illinois, Urbana-Champaign.
The mystery of the disappearing bees
Almost everyone got an inkling of just what that could mean recently when millions of honey bees mysteriously disappeared – a phenomenon known as Colony Collapse Disorder, or CCD. The case of the disappearing bees grabbed headlines all over the country, amid much speculation but few answers about what caused the problem.
But, warns Adams, “CCD and honey bees are just the tip of the ‘pollination iceberg.’ The health of nearly 4,000 other species of bees in the U.S., as well as butterflies, bats, birds, beetles, and other pollinators require immediate attention.”
The NAPPC is getting a helping hand from some big guns this week to help spread the word.
Help from scientist, Postal Service
Pulitzer Prize-winning scientist Edward O. Wilson lends his support to the continental coalition of pollinator advocates by speaking about the important role that birds, bees, butterflies, and other pollinating animals play in agriculture, ecosystems, and biodiversity.
Dr. Wilson, best known for his socio-biological work, On Human Nature, is also a biodiversity expert and the recipient of the highest award given in the field of ecology, the Crafoord Prize – the ecological equivalent of the Nobel Prize. His appearance at the USDA this week is expected to include actions that the public can take to support wild as well as managed pollinator populations in their own communities.
Also this week, the U.S. Postal Service will do a first day issue (June 26) of a booklet of 20 commemorative stamps entitled “Pollination,” featuring the art of Steve Buchanan. The artist created an intricate graphic scheme showing bees, bats, birds, and butterflies pollinating plants and flowers to teach stamp-buyers about the ecological process and for use in communities and schools (see illustration of the stamps, above right).
Learn more about the situation
One way of tackling the problem is to learn more about it, and discover ways in which you can help.
In August, Morris Arboretum of the University of Pennsylvania will co-sponsor a two-day conference on "Invasive Plants: Research, Removal and Renewal."
It's not strictly speaking about pollinators, but on August 16, Prof. Tallamy will speak on "The Role of Native Plants in Our Fight to Preserve Biodiversity." And on August 15, author and garden designer C. Colston Burrell will present the keynote address, on "Native Alternatives to Invasive Plants."
Conference details are below if you want to sign up.
What gardeners can do for pollinators
• Create a pollinator-friendly garden habitat in just a few simple steps.
• Design your garden so that there is a continuous succession of plants flowering from spring through fall. Check for the species or cultivars best suited to your area and gradually replace lawn grass with flower beds.
• Grow plants native to your region, using plants that provide nectar for adults plus food for insect larvae, such as milkweed for monarch butterflies. If you do use non-native plants, choose ones that don’t spread easily, since these could become invasive.
• Select old-fashioned varieties of flowers whenever possible, because breeding has caused some modern blooms to lose their fragrance and/or the nectar/pollen needed to attract and feed pollinators.
• Install houses for bats and native bees. For example, to attract bees, use wood blocks with holes or small open patches of mud. As little as 12 inches across is sufficient for some bees.
• Avoid pesticides, even so-called “natural” ones such as Bacillus thuringiensis (Bt). If you must use them, use the most selective and least toxic ones, and apply them at night when most pollinators aren’t active.
• Supply water for all wildlife. A dripping faucet or a suspended milk carton with a pinhole in the bottom is sufficient for some insects. Other wildlife need a small container of water.
• Provide water for butterflies without letting it become a mosquito breeding area. Either refill containers daily or bury a shallow plant saucer to its rim in a sunny area, fill it with coarse pine bark or stones and fill to overflowing with water. Butterflies can drink from the cracks between the filler but mosquito larvae have a hard time becoming established.
For More Information...
For more information about International Pollinator Week, go to www.pollinator.org; for information about the North American Pollinator Protection Campaign, visit www.nappc.org; to read the National Academy of Science report on "Status of Pollinators in North America," go to www.nap.edu.
For information on the conference on "Invasive Plants," to be held at the University of Pennsylvania on Aug. 15 and 16, visit www.morrisarboretum.org. For a downloadable registration form, click on Education and Symposia and Seminars.
For information about native plants in this region, check out the web sites of Bowman's Hill Wildflower Preserve at www.bhwp.org, or the Brandywine Conservancy at