As last week’s Congressional Research Service report on bee health makes clear, the crisis plaguing pollinators is not a single, big bad bogey man. It’s likely a combination of factors such as habitat loss, pesticide poisoning, introduced diseases and the stress of making domesticated honey bees the insect equivalent of migrant workers. That’s the bad news. The good news is that complex problems call for solutions based on complex systems. That’s why a more diverse, sustainable agriculture could play such a key role in helping pollinators.
Pollinators—wild creatures and domesticated honeybees—help 70 percent of the world’s wild and cultivated flowering plants reproduce. Every third bite of food is directly or indirectly the result of an insect carrying a few grains of pollen from one flower to another. Honeybees alone pollinate approximately $15 billion to $20 billion worth of American crops each year, according to the USDA.
Bees purposefully collect pollen to feed on its rich protein, but a variety of creatures participate in pollination, often accidentally, when they travel between plants. Butterflies, moths, wasps, flies, ants, bats, hummingbirds, and yes, mosquitoes, play a role in plant pollination, although they do not feed on pollen.
Without pollinators we would have to say goodbye (or at least do with less) tomatoes, squash, melons, cranberries, almonds, blueberries, cherries, asparagus, broccoli, carrots cucumbers, onions, and various tree fruits like apples, to name a few. And because pollinating insects are needed to produce seeds for forage crops like alfalfa, our meat and milk are partially reliant on their services.
“Pollinators are really the keystone group of organisms that other organisms rely on,” Eric Mader, assistant pollinator program director at the Xerces Society for Invertebrate Conservation, told me. “Losing pollinators is probably equivalent to the ramifications of losing all our oxygen. I don’t want to be an alarmist, but these are keystone species.”
That’s why farmers, environmentalists and even consumers should be concerned by this troubling fact: pollinators—everything from the domesticated European honeybee to the wild bumblebee—are quickly declining.
But this agro-environmental crisis offers a sweet opportunity for farms that contain diverse habitats full of flowering plants and other natural areas. Such wildly successful farms could serve as pollinator havens while remaining productive. Because pollinators are such critical species, doing things that benefit them could provide multiple ecological services: from improved water quality and carbon sequestration as a result of more perennial plant cover, to habitat for birds and mammals. And the perils facing pollinators provides an opportunity for average consumers to take part in the solution.
Collapse of the colony
If it weren’t for “Colony Collapse Disorder,” also known as CCD, showing up in this country about half-a-dozen years ago, the importance of pollinators would probably have gone unnoticed by the public. The USDA estimates that overwinter honey bee colony losses from 2006 to 2011 averaged more than 32 percent annually.
Honeybees have experienced massive die-offs in the past, but CCD is particularly troubling because it occurs when worker bees leave the hive and don’t return, a behavior quite unusual for the highly organized domestic honeybee, Marla Spivak, a University of Minnesota entomologist and nationally-recognized expert on bees, told me.
Such catastrophic losses have sent beekeepers and scientists scrambling for solutions. It’s of particular concern to the California almond industry, which has become increasingly reliant on the pollination services provided by honeybees. In February and March each year, half of the nation’s hives are in California providing pollination services for almond groves.
The health food industry’s skyrocketing demand for almonds has made hives from top beekeeping states like Minnesota, South Dakota and North Dakota high demand items, with hive rental rates at least tripling in just a few years. Today, most commercial beekeepers no longer rely on honey sales to make a living—rather they move their hives around to various parts of the country to provide pollination services.
In fact, the collapse of honeybee colonies may be the result of expecting too much from these apian workhorses. After all, since the 1950s in the U.S. alone, the number of crops we need pollinated by bees has doubled, while the number of honeybees has dropped by at least half. It’s like a factory where half the workers have been laid off while the assembly line has been sped up.
And all of that traveling and concentration of hives in a feedlot-like environment exposes the bees to an alphabet soup of diseases they aren’t used to dealing with. In her cramped office next to the bee lab at the University of Minnesota, Spivak showed me a computer graphic illustrating the migration patterns of beehives each winter. Large swooshing arrows represent the movement of Midwestern hives South and West in the winter, and back again in the spring.
“This huge movement horizontally has increased the disease transmission significantly,” said Spivak.
Bees and other pollinators are notoriously sensitive to pesticide poisoning. And because bees are natural born collectors, they often bring contaminants such as pesticides back to their hives. A Penn State University study released in 2008 showed that low levels of over 70 pesticides and metabolites of those pesticides were present in hives. Most of them were common insecticides and herbicides used in agriculture and around the home. Penn State researchers are particularly concerned that when the pesticides combine in a hive, they can have a synergistic effect hundreds of times more toxic than any of the pesticides individually.
Fortunately, labeling restrictions (no spraying during the middle of the day when bees are most likely to be foraging) and a transition to chemicals of lower toxicity have made it less likely bees will be outright killed by spraying.
However, recent research has shown that a relatively new class of pesticides could offer a more insidious threat to bees and other pollinators. In recent years, organophosphate insecticides, which are toxic to mammals and birds, have been replaced by a class of pesticides called neonicotinyls.
Derived from nicotine, these bug killers are systemic, meaning they are put on a plant’s seed, or injected straight into the roots or stem. They work their way up to the leaves, killing insect pests that feed on the plant. The advantages to these kinds of bug killers are many: for one thing farmers, greenhouse keepers and homeowners aren’t spraying toxins in the open air, reducing the chance of the chemical going where it’s not supposed to. In addition, it works specifically on insects, offering little threat to other creatures, including humans.
That’s the main reason neonicotinyls have become one of the most widely used pesticides—particularly in greenhouses, by landscape companies and in homes. If you bought a potted plant recently, likely it’s been fortified with neonicotinyl.
“I can’t impress on you how common this is on everything,” said University of Minnesota entomologist Vera Krischik, adding that these types of pesticides can stay in a plant for up to a year.
The effects of neonicotinyls on non-target species such as bees is of particular interest now that the emerald ash borer, a devastating killer of ash trees, has arrived in the Midwest. This class of pesticides is an effective tool for controlling the borer.
“This pesticide isn’t all bad. It’s just not a good idea if it finds its way into plants insects use for nectar,” Krischik told me.
Bringing in wild help
One way to reduce stress on honeybees—whether it’s from disease, overwork, pesticide poisoning or a combination of all three—is to tap into help from the wild. Wild insects already provide roughly 15 percent of food crop pollinator services. In the Upper Midwest, the potential for native species to transport pollen is huge—Minnesota, Wisconsin and Michigan alone have more than 500 species of native bees.
In many ways, native bees are superior pollinators to domesticated honeybees. Bumblebees will fly in bad weather when their domestic cousins are holed up. As few as 250 orchard mason bees—native metallic-tinted bees present throughout the country—can pollinate an acre of apples, a job that could require 40,000 honeybees. A bumblebee can cling to inverted flowers such as blueberries and efficiently buzz pollinate—shake pollen off by vibrating its wings.
“Bees are the apex pollinators,” Mader said. “Bumblebees are the most efficient of the efficient.”
But wild pollinators are having their own problems.
The National Academy of Sciences reported in 2007 that long-term population trends for North American wild pollinators are “demonstrably downward.” At least four dozen species of wild bees in this country are on the Xerces Society’s “red list” of at-risk pollinators.
The U.S. Fish and Wildlife Service has gotten so concerned about the loss of native pollinators that it has launched its own pollinator conservation effort. Not only are insects like bumblebees important for propagating wild flowering plants, but their sensitivity to the environment makes them key ways of monitoring what’s going on in the ecosystem, say wildlife experts.
The issue that overshadows every other threat to wild and domesticated pollinators is lack of natural habitat to forage on and live in. Diverse landscapes can go a long ways toward making beneficial insects more resilient in the face of disease, toxic chemicals and general stress, say entomologists and ecologists. And this is where diverse, sustainable farms can play a role.
Research shows that farms with woods, meadows and other natural areas growing flowering plants have a larger number of insect pollinators. But monocultures of corn, for example, are deserts to pollinators. Beekeepers often get panicked calls from vegetable producers who are trying to raise melons and other pollinator-dependent crops in the midst of corn country.
In addition, heavy tillage disrupts wild bee habitat—two-thirds of native bees nest underground. And according to a paper just published in the entomology journal Psyche, plants grown in healthier soil—in this case soil treated with earthworm compost to increase biological activity—produced plants that are much more attractive and nutritious when it comes to pollinators. That study found plants grown in chemically-treated soils were less likely to attract pollinators such as bees. And when they did visit those plants, the insects found them less nutritious. Chalk that up as one more reason we should be excited about efforts in the Midwest to improve soil health on farms.
Minnesota beekeeper Darrel Rufer once provided me a graphic description of how natural habitat benefits pollinators. Rufer noticed that when wintering his honeybees in a part of east Texas where natural habitats such as woodlands predominate, the insects came back to Minnesota in May seemingly rejuvenated. That means they do well during the first part of the summer, when blooming plants like dogwood and basswood provide plenty of healthy nectar. By the end of June and the first part of July, the bees are forced to begin foraging in cornfields, which offer them little nectar and can be full of pesticides. That’s when the bees start to lose their vigor.
“Progressively with each trip to the beehive you have fewer and fewer bees,” Rufer told me. “You’ll have clusters that will have instead of 10 frames you’ll have three. Plus you’ll have more dead bees around.”
Congress, prompted by concerns over the loss of honeybees, made pollinator research and protection one priority in the 2008 Farm Bill. In fact, last week’s CRS report is partially a result of that effort. In addition, the Natural Resources Conservation Service (NRCS) has been directed to make pollinator habitat restoration and protection a key part of such initiatives as the Conservation Reserve Program and the Conservation Stewardship Program.
NRCS guidelines in many states recommend at least one to two acres of pollinator habitat for every 25 acres of pollination-dependent cropland. And it needs to be relatively close. Bumblebees will range up to a mile from their nest to forage, while for tiny solitary bees (some species are small enough to ride on a bumblebee’s antenna), a flight of 200 yards would be a major undertaking.
Botanists and entomologists say careful planning is needed when planting for pollinators. The peak of pollination may be August, but insects need nectar throughout the growing season, particularly during the fall as they prepare for winter. That means diverse plantings that bloom throughout the spring, summer and fall are key.
Beneficial habitat can be had in some surprising places. Research out of Kansas has shown that “linear habitat corridors”—native prairie plantings along roads—can produce major habitat benefits for pollinating insects. Over twice as many wild bees were found along roads planted to native prairie as compared to weedy roadsides, according to one University of Kansas study. In Iowa, over 45,000 acres of roadsides have been planted to native plants during the past few decades, providing pollinator habitat as well as other benefits such as natural snow fences.
But it doesn’t necessarily take thousands of acres of wild habitat to help pollinators—sometimes just a little splash of diversity will help. Pollinator-friendly habitats on farms can take the form of hedgerows, dead snags, bare ground for bee nesting and native plant systems. Flowering trees such as willows can be critical to bees when they emerge in the spring, while asters, goldenrod and sunflowers are key sources of food in late summer and fall. Even allowing vegetables like broccoli to bolt late in the season can help. (An LSP podcast features entomologist John Luhman talking about the importance of small patches of habitat.)
Pollen & the plate
The beauty of pollinator conservation is that because these creatures play such a key role in the food chain, anyone that eats can play a positive role by creating a “demand” for diverse habitat. Beekeeper Brian Fredericksen has developed a business model based on such a relationship. On a late summer afternoon, Fredericksen showed me his honey processing facility west of Minnesota’s Twin Cities, near the town of Watertown.
A counter on one side of the climate-controlled room held meticulous records of the work Fredericksen’s bees have been doing during the previous months. Documented were where the hives are located and the type of plant the bees collected pollen from. The beekeeper pulled out a few jars of the finished product to show how that data is put to use. One label makes it clear that some “Dutch Clover” honey was collected from Hive 609A at Parley Lake. Another was collected on the Blue Earth River (Hive 354A), yet another from Meadow Wood (Hive 504A).
The list goes on. Fredericksen’s Ames Farm business has several different labels, representing hive locations that range from central Minnesota all the way down to near the Iowa border. Such a diversity of locations means a lot of work is invested in maintaining the hives, but it’s worth it, said Fredericksen.
“If some feedlot bee guy moves in next door, I won’t get wiped out by disease because I am diversified in location,” he said. (Listen to an LSP podcast featuring Fredericksen.)
This isn’t just a hive-survival insurance policy. Fredericksen sees “single source honey”—being able to track the product back to one hive from one location representing one type of plant—as a viable way to make a living from bees without shipping them all over the country. This artisanal method of honey production results in a flavorful product consumers are willing to pay extra for—providing a direct, market-based mechanism for supporting healthy habitat for local pollinators—both wild and domesticated honeybees.
But the beekeeper also sees it as a way for consumers to do things on a bigger, landscape scale and support the overall natural infrastructure required for a type of honey production that preserves wild habitat. If eaters are more aware that top-quality honey requires diverse habitat, they may be more likely to do everything from establish native plantings on their own property to encouraging local governments to reduce chemical-intensive landscaping. They may also see the importance of supporting government policies that encourage, rather than discourage, farmers who diversify out of corn and soybean monocultures.
“Maybe while they’re spreading honey on their toast people will be reminded that it takes a certain habitat to produce this product locally,” said Fredericksen as he left the honey packing facility. “Everybody can pitch in on this one.”