Metro Atlanta Beekeepers Association

Saving Bees: What We Know Now

 By The Editors. The New York Times. September 2, 2009.

The first alarms about the sudden widespread disappearance of honey bees came in late 2006, and the phenomenon soon had a name: colony collapse disorder. In the two years that followed, about one-third of bee colonies vanished, while researchers toiled to figure out what was causing the collapse. A study published last week in the Proceedings of the National Academy of Sciences surmises that there may not be a single pathogen involved but a collection of culprits. What have entomologists and beekeepers learned in the last few years of dealing with the crisis? We asked May R. Berenbaum, an author of the study, and other experts for an update.

Living with a Crisis

Marla Spivak is a professor of entomology and social insects at the University of Minnesota.

 All bees — honey bees and native bees — are still in decline, and it is a serious issue. It is true there is less news coverage of bee health issues, but bees are not faring better. Over 30 percent of our honey bee colonies die every year, from colony collapse disorder or other causes. Some native bumblebee species have become nearly impossible to find, and we don’t know how many other native bees are threatened.

Beekeepers are treading water, replacing as many colonies as economically feasible for their operations. Researchers are hard at work using cutting-edge methods to determine why honeybee colonies are collapsing and how we can mitigate the decline of all bees.

 While bees may have faded from the news, they have not faded from the public eye. In fact, the opposite has occurred. People are more aware than ever about bees. The crisis has helped us understand the importance of pollinators to our diet and environment and many people want to know how they can help.

 What can we do to help bees? Plant lots of flowers that provide nectar and pollen for bees, and reduce pesticide use. These two tangible and relatively easy actions, when implemented by many people, can save our bees and restore health and diversity to our agricultural and urban landscapes.

A Viral Overload

May R. Berenbaum is a professor of entomology at the University of Illinois at Urbana-Champaign.

 A few things have changed with respect to colony collapse disorder (CCD) in the past year. First, whereas surveys conducted by the Apiary Inspectors of America estimated CCD losses in America’s managed honey bee colonies during the winters of 2006-2007 and 2007-2008 at 36 percent and 32 percent, over the winter of 2008-2009 losses dipped to 29 percent, possibly indicating a decline in severity.

Secondly, an extensive survey conducted by researchers from two land grant colleges, the United States Department of Agriculture (USDA) and two Belgian universities examined adult and larval bees and hive products from almost 100 colonies for parasites, pathogens, pesticides and nutritional factors. Although no single diagnostic difference was identified, one consistent finding was that colony collapse disorder bees were infected with multiple pathogens; over fifty percent of CCD colonies, e.g., were infected with three or more viruses, almost twice the percentage of healthy colonies.

 Most recently, a whole-genome honey bee microarray analysis allowed investigators from the University of Illinois at Urbana-Champaign and the USDA to examine differences in patterns of expression of all 10,000+ genes in the honey bee genome, the sequencing of which was completed in 2006. Multiple comparisons of hives varying geographically, temporally, and in CCD severity winnowed the list of genes whose expression was most closely associated with the disorder down to a handful representing fragments of ribosomes, the “protein factories” of the cells, thus implicating ribosome breakdown as a “root cause” of CCD.

Genetic material from common bee pathogens, also on this microarray, revealed, as before, that CCD bees were infected with a greater number of viruses, specifically picornalike viruses, all of which cause infection by hijacking the ribosome, reprogramming the “factory” to make viral proteins instead of honey bee proteins. Thus, viral overload may lead to ribosome breakdown, which is manifested as CCD. Together these studies may explain why so many explanations of colony collapse disorder seem plausible; in the absence of functional ribosomes, bees would be hard-pressed to respond to any of the multiple stresses to which they are subjected in 21st century apiculture — pathogens, pesticides or nutritional deficiencies. Detecting the ailment early might give beekeepers a chance to provide supportive care.

As for practical applications of these findings, the most immediately useful product of the microarray study is an objective genetic diagnostic indicator of colony collapse disorder — the ribosome fragments. Such a diagnostic indicator would be useful in determining whether other CCD-like disappearances in England, Spain and elsewhere are in fact colony collapse disorder or entirely different in origin.

Early diagnosis of the ailment might not be directly useful — there are no vaccines to combat bee viruses and no known ways to patch up broken ribosomes — but beekeepers who detect this breakdown early on may be able to provide supportive care to help their bees recover.

Needed: More Disease-Resistant Bees

Diana Cox-Foster is a professor of entomology at Pennsylvania State University.

In the almost three years since the plight of honey bees caught the public’s attention, we have learned that bees are faced with many different obstacles, some naturally occurring (such as diseases) and others that are byproducts of human activity.

The honey bees in the U.S. have been in trouble since the introduction of parasitic mites (Varroa and tracheal mites) in the late 1980’s. Varroa has continued to be the major problem, in part because the mites have become resistant to the acaricides used for control.

Our study of hundreds of pollen samples showed on average six different pesticides. Do chemicals impair bees’ immune systems?

Colony collapse disorder (CCD) has severely affected many beekeepers in the United States and caused some to go bankrupt. We have learned much about CCD, but we are still a long way from determining its exact causes and how to mitigate this disease. Of major worry is that these same causes may be affecting native insect pollinators. This translates into concerns not only for security of our food crop production but also for the overall health of the ecosystems that we depend upon for survival.

Data indicate that colony collapse disorder here in the U.S. has a common set of symptoms that differ from colony losses associated with late-summer or over-winter death. CCD colonies have elevated levels of at least one of three closely related viruses: Israeli Acute Paralysis Virus, Kashmir Bee Virus or Acute Bee Paralysis Virus. The microsporidian parasite Nosema ceranae by itself does not appear to be a major cause of hive mortality in the U.S.

Studies at Penn State indicate that Israeli Acute Paralysis Virus can cause some of the symptoms of CCD. However, we think that stress is an added major component and that other microbes and parasites present in the bees play a role. Stresses such as sub-lethal pesticide exposure and lack of adequate nutritional sources (pollen and nectar) may be affecting the bees. In hundreds of samples of incoming pollen, a team at Penn State and the USDA has found that over ninety-nine percent have at least one pesticide contaminant, on average six different pesticides, and up to 35 different pesticides in a single sample. Over 100 different pesticides have been identified.

What impact do these chemicals have on bee health via impairment of bee’s immune system to fight off diseases like viruses, through impact on bee behavior, or by decreasing colony build-up and reproduction? We have preliminary data to suggest that all of these aspects are part of the problem, but we do not know to what extent or exactly how, preventing mitigation of this stress.

New approaches are needed to mitigate the problems in pollinator health. It is clear that our recent recommendations to the beekeepers are having a positive effect: sterilize the equipment from collapsed colonies using gamma irradiation, use soft chemicals to control Varroa mites and Nosema, and feed artificial pollen when needed. Prior to CCD, these measures would not have significantly affected overall colony survival. However, these are temporary Band-Aids; these methods are costly and do not eliminate the underlying causes.

Beekeeping operations need sustainable solutions to stay in business and provide essential pollination services. Needed are new strains of bees with more resistance to diseases and parasites. The impact of pesticides needs to be lessened.

Lastly, bees need more flower or pollen/nectar sources nationwide. In summary, we are a long way from “solving” the pollinator crisis.

Bias Against a Non-Native Species

Joe Traynor is a bee broker for apiarists and almond growers. His company, Scientific Ag, is based in Bakersfield, California

.The current consensus is that honey bee problems are caused by multiple stressors. Bees, like us, carry viruses and harmful microbes all the time. When we (and they) get run down, these nasties can take over, making us sick. Colony collapse disorder peaked during 2007, which was also a year, due to drought conditions in many areas of the U.S., that good bee forage was in short supply; as a result, honey bees suffered nutritionally, making them more susceptible to viruses carried and transmitted by varroa mites and to a new (to the U.S.) fungus, Nosema ceranae, believed to have been introduced here in 2007.

Possible culprits: developers, second-home buyers, corn producers — and conservation purists.

Bee forage was more plentiful during 2008 and as a result there were less incidences of CCD.  We won’t know for a while how 2009 will turn out. Beekeepers that have kept their bees in top shape nutritionally have had lower than normal problems with colony collapse disorder.

There is no question that annual honey bee losses are far greater today than they were 20 years ago. Twenty years ago, before virus transmitting Varroa mites were found in the U.S., 10 percent winter losses were normal.  Now 20 percent losses are normal and losses hit 36 percent in 2007 and around 30 percent in 2008. Beekeepers have to work much harder to keep their bees in good health than they did 20 years ago. This means paying close attention to nutrition, via supplemental feeding of both proteins and carbohydrates, and controlling both Varroa mites and Nosema, easier said than done as there are limited means of controlling these two pests.

Natural bee forage, including some agricultural crops, is better for bees than artificial supplements. Bees, like us, require a varied diet to remain in top health. The ethanol boom has caused corn, a poor pollen source for bees, to replace clover and alfalfa, relatively good bee plants, in some parts of the U.S.

Increased urbanization, especially here in California, has resulted in the loss of excellent bee pasture. When baby boomers build a second home in the foothills of California (or in Montana) they don’t want any bees near their homes, so the first thing they do is evict beekeepers from long-held locations.

Counterintuitively, the Nature Conservancy has also contributed to honey bee problems. The group purchases large tracts of undeveloped land for the laudable purpose of preserving these tracts in their native state for future generations. Unfortunately it has a policy of evicting all non-native species from the property it acquires. This includes honey bees since they are an introduced species, brought over from Europe by early settlers.

The Nature Conservancy recently took over a large tract of land in San Diego County that provided sustenance for many commercial bee colonies. The bee colonies were evicted and are now competing for ever diminishing bee pasture in the San Diego area.  (There are probably 100,000 commercial bee colonies competing with each other in San Diego County alone.) 

Evicting commercial (European) bees from Nature Conservancy holdings is shortsighted as it creates a vacuum that allows Africanized honey bees, which are prevalent in Southern California and are becoming more prevalent in other parts of the U.S., to establish themselves on the group’s property.

The recent finding of fossilized honeybees in the U.S. (thousands of years old but now extinct) may cause the conservancy to change its policy, but beekeepers aren’t holding their breath on this.

The costs of keeping bees in good condition to ward off colony collapse disorder have increased dramatically over the past two years. A main reason CCD has decreased this past year is that beekeepers are spending much more time and money keeping their bees healthy.

Increased pollination fees for agricultural crops requiring honeybees are paying for these increased bee maintenance costs.

Profound Changes

Kim Flottum is the editor of Bee Culture, the Magazine of American Beekeeping and the author of The Backyard Beekeepe” and The Backyard Beekeeper’s Honey Handbook.

Pesticides, bacterial diseases and varroa mites have been implicated in the search for the causes of colony collapse disorder. Plus, viruses in conjunction with environmental stresses are suspects, and University of Illinois scientists have discovered what occurs at the genetic level of CCD. I suspect it is only a matter of time before the pathogens are known.

Meanwhile, individual beekeeping operations have been damaged, some beyond repair because of this malady. Others have been able to recover. The overall picture is, however, not quite as bleak as the press and the blogosphere might lead you to imagine. Colony numbers in the U.S. show the resiliency of American beekeepers.

But beekeepers know that changes are necessary. The changes involve effective and efficient management of Varroa mite populations. A beekeeper’s obvious first choice is to manage honey bee lines that are resistant to or tolerant of these mites. But there is a very limited quantity of these bees, and they are expensive. Or beekeepers can choose a line of bees that tolerates mites to a great degree, but differ in behavior from the bees they are familiar with. Russian bees are resistant to the mites, but their seasonal timetable is much different from that of the bees most U.S. beekeepers are used to.

In particular, Russian bees require extra work in late fall and early winter to accommodate the mid-winter almond crop in California. Almonds bloom in February and March, much earlier than any other major pollination crop. More than half of the honey bees in the United States are used to pollinate almond orchards, and many, if not most, migratory beekeepers depend on the crop for pollination income. The migratory beekeeping industry goes as the almond crop goes, and the crop is suffering from water shortages, price fluctuations, and beekeeper availability due to CCD and other forces.

The only alternatives to the use of resistant honey bees are chemical miticides that effectively and efficiently control Varroa mites while they are in the hive. Newer products using essential oils are safe and effective but labor-intensive, while traditional choices require less labor but are less effective.

Reducing the insidious use of pesticides on everything honey bees eat has been a priority.

But for the longer term commercial beekeepers have concluded that if they are going to succeed in the migratory pollination business, they need to change and attend to the discoveries made in the search for clues to colony collapse disorder.

High on beekeepers’ lists, besides controlling Nosema ceranae, is reducing the insidious pesticide barrage applied to everything honeybees eat, and insuring that bees’ nutritional needs are met by feeding them better food more often. These management changes have been rapidly accepted and have lead to profound improvements in honeybee health.

The benefits? The pesticide abuse debacle in this country may have finally come to a head, and discussions among beekeepers, the Environmental Protection Agency and agricultural pesticide companies have begun.  But is the new E.P.A. better than the last, and are chemical companies on the level? Plus, honeybee health has gained more attention and made more progress in the last two years than the last three decades. Better resistant bees are next in line.

But most important? Awareness of the value of the beekeeping industry to the production of the food we need is better understood now than perhaps ever before.