Welcome mat for bees
Nonprofit group leads way in helping to develop habitat
Friday May 9, 2008
THE DALLES, Ore. – It couldn’t have been a nice way to wake up on a cold spring day.
After an entomologist dug it up from its comfy underground home overlooking a cherry orchard, the longhorn bee was placed in a tiny glass vial and passed among a crowd of curious onlookers.
To the orchardists, university extension agents and others in attendance, the sleepy insect was proof that a patch of bare soil on a scraggly hillside could serve a worthwhile purpose: as a home for native pollinators.
“There’s all sorts of different places where you can squeeze habitat in,” said Matthew Shepherd, conservationist with the Xerces Society, a nonprofit invertebrate preservation group that is organizing a series of native pollinator workshops in Oregon.
The problems plaguing commercial honeybees have attracted a lot of attention since late 2006, when roughly one-fourth of U.S. beekeepers lost about 45 percent of their hives, he said.
Mites, protozoan parasites and the mysterious Colony Collapse Disorder threaten honeybees – and thus crop pollination – but native species, like several types of bumblebees, are also in trouble, said Shepherd.
Diminished habitat, disease, improper pesticide use and other factors have reduced the populations of such native pollinators, according to the Xerces Society.
This is bad news for pollinator-dependent farmers, since native species can greatly improve crop production, said Shepherd. Each year they contribute about $3 billion to the U.S. economy, according to the Xerces Society.
Studies on sunflowers and cherry tomatoes, for example, have linked native pollinators with a doubling and tripling in yields, respectively, he said.
Native pollinators are unlikely ever to replace commercial hives, but they can obviously be a useful supplement, said Shepherd. As demonstrated in sunflowers, their presence during pollination compels honeybees to fly among a larger number of flowers instead of lingering amid just a few, he said.
“The native bees kept the honeybees moving,” Shepherd said.
Whereas honeybees might not venture from the hive in cooler temperatures, native pollinators are more apt to collect pollen and nectar in spite of the weather because they don’t have a honey supply to fall back on, he said.
“If they don’t go out during the day, they go hungry,” Shepherd said.
Farmers also stand to benefit from the lack of rental fees for native pollinators, although they should be under no illusion that the insects are free, he said.
To entice native bees to visit their fields, growers need to create habitats where the insects can live and feed, even when no crops are in bloom, Shepherd said.
In California watermelon fields, growers were able to achieve full pollination without honeybees if they left roughly one-third of the crop field’s vicinity in natural habitat, he said.
About two-thirds of the 4,000 native pollinator species in North America nest underground, while the rest live in wood snags, Shepherd said.
Before growers set out to create habitat, though, they should first identify what native species already exist on their farms, he said. Then they should adopt practices that prevent harm to insects, such as not spraying when plants are in bloom, he said.
When designing a habitat, it pays to remember that not all flowering plants are created equal, said Mike Omeg, general manager of Omeg Orchards, where a Xerces Society pollinator workshop was recently held in The Dalles, Ore.
Though some plants will attract beneficial predatory insects, others will harbor pests, so varieties should be chosen carefully, he said. “You need to be clever about how you do it.”
Other practical challenges need to be considered as well, which is why growers should start out small when creating habitat, Omeg said. “I’m taking baby steps because I don’t want to make expensive mistakes.”
For example, Omeg hasn’t had luck with pollinator-friendly plants between the rows of his cherry orchards: They seldom withstand heavy machinery, he said.
Instead, he is planting cat mint in recycled fruit bins, which allows him to transport the plants throughout the orchards as necessary. Omeg is also planting and irrigating a one-acre parcel adjacent to his orchards to specifically serve as an “insectary.”
Sometimes, however, developing pollinator habitat is a matter of what growers don’t do, said Paul Jepson, environmental and molecular toxicology professor at Oregon State University.
Farmers can simply avoid cultivating “scab” areas, like the scraggly hillside above Omeg’s orchard where the longhorn bee was dug up and eventually returned, he said.
“It doesn’t have to be a perfectly manicured and engineered to be good habitat,” said Jepson.
Staff writer Mateusz Perkowski is based in Salem, Ore. E-mail: firstname.lastname@example.org.
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