Fighting for the Bees

As if it weren't bad enough that a mysterious decline in honeybees is threatening our nation's fruit, vegetable and flower crops and honey production, consider this: Many of these yield the ingredients that go into ice cream. That's why, with nearly 40 percent of Haagen Dazs flavors depending on bee-pollinated ingredients, the ice cream giant recently introduced a new flavor, Vanilla Honey Bee, and launched a Web site (www.helpthehoneybees.com). Haagen Dazs' aim: to raise the public's awareness about what's known as Colony Collapse Disorder (CCD), as well as raise money for research to save the bees-and consequently the future of American and European agriculture.

In fact, since its arrival on our shores with European colonists in the 1600s, Apis mellifera has shaped the American landscape (1). You only have to go back as far as your high school biology class, however, to understand the important job bees carry out. All summer long, worker bees-of which a single colony might have between 20,000-80,000-forage from flower to flower in their quest for the nectar used to make honey back at the hive. As they work, their fuzzy bodies collect pollen that's transferred from the stamen to pistil. The fertilized flower becomes a fruit bearing seeds for the next generation of plant. It's a natural win-win scenario, brought to a field-and table-near you via co-evolution.

It may be hard to believe these few links on the food chain could have such a huge impact, but make no mistake: Even with the advances in agricultural technology, we rely on this species of bee to pollinate plants that make up one third of our food supply-everything from apples and oranges, to almonds and corn-grown on 3.5 million acres and worth roughly $15 billion (2).

As industrious as the honeybee is, it's a fragile creature. It is the colony that endures. Normal colonies that are healthy overall harbor many diseases without noticeable or extreme loss of life. Your typical colony persists despite mite infestations and bacterial, viral, fungal and parasitic infections, diminished nutrition and pesticide exposure, even increased stress or a heightened susceptibility to such threats due to decreased genetic diversity. Any time temperatures drop below 50 degrees, large die-offs of bees can occur, but the colonies rebound when warmer weather returns. That is nature's ebb and flow.

Colony Collapse Disorder, first reported in late 2006, is something much different. For whatever reason, a well-stocked hive is abandoned, larvae left behind. The adults simply disappear; no bodies can be found to autopsy. Even more haunting, the hive seems off-limits to common opportunistic pests such as the wax moth and hive beetle, who typically prey on weakened colonies (3).

Just what drives the bees out of their hives, never to return, is a mystery. Is it an emerging disease organism? Is it a combination of factors in a straw-that-broke-the-camel's-back scenario?

So far, researchers have identified 18 pathogens in bees from colonies experiencing CCD (2). Their work is like piecing together a complex puzzle. Many pathogens found in some colonies aren't present in others. Most of the identified pathogens were found in CCD and in healthy hives. Other pathogens have been ruled out because the known symptoms and effects are not those of CCD.

One pathogen, Israeli acute paralysis virus (IAPV) present in every CCD colony analyzed in one study, has been singled out for increased scrutiny. The virus was introduced to the United States via recently imported Australian honeybees. Bees with IAPV develop shivering wings and paralysis before ultimately dying, although usually just outside the hive. The varroa mite, prevalent in the United States, weakens the immune system of the bees, and may make them more susceptible to IAPV. The virus is present in Australia, but in the absence of the varroa mite, the bees do not suffer to the extent seen with CCD in the United States. Traces of IAPV were also found in royal jelly, a type of honeybee food, from China (4) . It's a tenuous thread of clues at this point, but at least one that has yet to run into a dead-end.

Blame has also been cast upon pesticides, especially neonicotinoids. This pesticide class, resembling nicotine, has largely been used since 1994. Like most pesticides, it poisons the nervous system of insects. Pesticides can harm non-target, or unintended, possibly beneficial insects. Social insects, such as bees, pose a particular challenge to evaluating pesticide toxicity. For example, lethal concentrations are established for individual insects but do not take into account resource pooling resulting in pesticide concentration within the hive. Further clouding the influence of pesticide toxicity is the fact that ingredients from not only pesticides in use but also those already banned continue to be identified in pollen, requiring researchers to screen for 175 or more active ingredients (2).

At Penn State, experiments are under way to replicate a colony collapse under controlled condition (2) . Entomologists, chemists, plant pathologists, beekeepers, elected officials and conservation groups have joined the fight to save the bee, and now so can you. Support local beekeepers by buying their honey and substituting it for sugar in your favorite recipes. Cultivate a bee-friendly yard by growing plants such as lavender, thyme, sunflower and coreopsis. Use pesticides sparingly and only as directed. Donate to organizations engaged in CCD research and support bee-friendly companies such as Haagen Dazs. And most of all, like the busy bee spreading pollen from flower to flower, spread the word about the threat to our beloved Ambrose mascot.

All food for thought when you're chanting "Go, Bees!" this fall-or the next time you take a bite of ice cream.

References:
(1) Elzinga, R.L. 2000. Fundamentals of Entomology. Prentice Hall.

(2) Williams, S. 2008. The Case of the Missing Bees. Penn State Agriculture Magazine.

(3) MidAtlantic Apiculture Research and Extension Consortium.

(4) Khamsi, R. 2007. Paralysing virus a suspect in disappearing bee mystery.