She's a Genius for Honey Bees
Last week, University of Minnesota entomologist Marla Spivak was awarded a $500,000 "genius grant" by the John D. and Catherine T. MacArthur Foundation for her work with honey bees. (David Simon, creator of TV's "The Wire" and "Treme," was among the other 2010 recipients.) Spivak started studying bees at the age of 18; she’s now 55, and over the course of her career, bees have grown in economic importance as growing numbers have been trucked around the country to pollinate crops, including apples, blueberries, almonds, and countless other fruits and vegetables. Yet over the same period, the health of bees has seen a steady decline, culminating in the phenomenon known as "colony collapse disorder," in which most bees within a colony simply disappear. (OnEarth first reported on this phenomenon in "The Vanishing" from our Summer 2006 issue.)
Since the 1940s, the number of managed honey bee colonies has fallen by half, to 2.5 million today. And just as mega-scale operations have led to trouble among meat processors and, lately, egg producers, bee keepers are experiencing problems, too, as exposure to pesticides, increased disease, and poor nutrition erode the health of hives. The upshot is a mortal crisis for bees -- keepers in the U.S. and Europe have seen up to half of their hives die from season to season in recent years.
Spivak has focused on breeding a better bee. By identifying behaviors that appear to help bees survive disease, Spivak has developed a "hygienic" bee strain that’s healthier than most; she has also advanced the fundamental understanding of bee biology on many fronts. In honoring Spivak, the MacArthur foundation cited the creativity, originality, and potential of her work. We caught her for a discussion just days after the award was announced last week.
The health of bee populations has worsened just in the past ten years. What’s changing?
The cause is humans. It’s our land use and how we treat our environment. The bees are holding up a mirror to us, showing they cannot live in this landscape. Crops are grown in huge monocultures requiring that bees be transported all over the U.S. to fulfill contracts -- to pollinate almonds, blueberries, apples, vine crops, and other fruits and vegetables.
How have our landscape and farming practices changed in ways that hurt bees?
It’s a combination of factors that influence one another. The first is nutrition. Both honey bees and our indigenous bees are compromised nutritionally due to a reduction in the amount of flowering plants. In particular, we’re growing less clover and alfalfa -- which both require pollination and are amazing bee food. Urban sprawl is also eating up farmland. Poor nutrition means the bees are more likely to be weakened, making them more vulnerable to the effects of naturally occurring diseases and parasitic mites and less resilient to the pesticides and farm chemicals that bees encounter.
What happened to those bee-friendly crops?
A half-century ago, as part of the process of crop rotation, farmers would let fields go fallow, growing clover on them between crops. The clover fixes nitrogen into the soil, which increases its productivity. But now instead of clover, commercial farmers rely on fertilizers made from fossil fuels to make the field more productive. It’s a similar story with alfalfa, which used to be grown widely for hay, to feed to cows and horses. But again, we’ve replaced that crop: corn and derivatives are used as feed instead. Plant variety on farms was also once more mixed, with wildflowers interspersed between crops. Now we kill all the weeds along the crop borders, further reducing bee habitat.
Are bee diseases spreading because of how we transport them for agriculture?
Moving bees isn’t the cause of disease. Commercial beekeepers are the unsung heroes in the fight to keep bees healthy. But increased demand for pollination has meant that when sick bees are moved, the problems spread, especially since many hives are already weakened due to disease, poor nutrition, and chemical exposure. Bees are trucked across the country and stockpiled for pollination services when different crops come into bloom. At this time of year, for instance, commercial beekeepers in the East will be getting ready to ship their hives to California for the almond blooms. Putting that many bees together in one place accelerates the spread of disease. It’s like if you’re sick, and you get on a plane, you risk transmitting that disease to everybody on the flight and wherever you land.
How does your work help the bees’ health?
In the vernacular, "hygienic" means cleanliness. In the context of my work, it refers specifically to the bees’ ability to detect diseased larvae in their nest and remove them before the disease becomes infectious. It’s similar to if you and I were on an airplane, and I could smell that you’re coming down with a cold and throw you off the flight.
In a colony, we can enhance behavioral tendencies through accelerated natural selection. We see which colonies are best at detecting and getting ride of the diseased larvae. Once we find colonies with this behavior, we can raise queen bees from them. I can then artificially inseminate that queen with semen from male bees from other hygienic hives. That queen will then lay new brood with a strong inclination for hygienic behavior. In this way, we can propagate these behaviors, and breed a line of hygienic bees.
Is climate change a problem for bees?
Native bees are having a harder time than honey bees. Native bees are extremely important pollinators and are in decline too, but don’t get enough press. Don’t forget, honey bees aren’t native to North America. And they’re more resilient because they hibernate. They can adjust how and when they find food in the spring. But native bees typically live and die in a season and have evolved in close synchrony with particular plants. If blooms have come and gone a month earlier because of warming, when the native bees emerge, they’ll starve. What’s more, many native bees are ground-dwelling, and their habitat is being eliminated, too. Their hives are being dug up for new construction or are harmed by pesticides.
Will the MacArthur grant let you do anything that you’ve been dreaming of?
I do have some fun ideas: to look at urban bee keepers and projects in bee breeding. I’m especially interested in developing a new bee research facility here in Minnesota, designed to be ideal for bees, highly accessible by the public, where visitors could come in see and hear bees in all their life stages all the time. They could learn how bee biology works, how honey is extracted, how landscapes affect them, how bees affect our food and health. I know what the world would look like if I could make it better for bees.