Colony Collapse Disorder and Pollinator Decline
Statement of
May R. Berenbaum
Professor and Head, Department of Entomology
University of Illinois Urbana-Champaign
and
Chair, Committee on the Status of Pollinators in North America
Board on Life Sciences and Board on Agriculture and Natural Resources
Division on Earth and Life Studies
National Research Council
The National Academies
before the
Subcommittee on Horticulture and Organic Agriculture
Committee on Agriculture
U.S. House of Representatives
March 29, 2007
Good morning, Mr. Chairman and members of the Subcommittee; thank you for the opportunity to talk
to you about colony collapse disorder and related issues affecting American agriculture. My name is
May Berenbaum and I am Swanlund Professor and Head of the Department of Entomology at the
University of Illinois at Urbana-Champaign. I recently served as chair of the National Research Council
Committee on the Status of Pollinators in North America; I also currently serve on the Council of the
National Academy of Sciences and am former chair of the NRC Board on Agriculture and Natural
Resources.
Background to Colony Collapse Disorder—Committee on the Status of Pollinators in North
America
The principal focus of this hearing is the sudden inexplicable disappearance of millions of honey bees
across the nation, a phenomenon called, for want of an identified cause, colony collapse disorder
(CCD). To understand the magnitude and potential impacts of this problem, however, it is important to
place it into the broader context of pollinator decline in general. Pollination is the process by which
pollen grains are transferred to receptive female floral parts to bring about fertilization. Because they
are for the most part firmly rooted in the ground, approximately 3/4 of the 250,000 + species of
flowering plants on the planet rely on mobile animal partners—pollinators—to carry out this vital
process. Over the past two decades, concern has grown around the world about apparent reductions in
the abundance of pollinators of all descriptions, with declines reported on no fewer than four continents.
During this same time period in the U.S., the western honey bee Apis mellifera, the world’s premier
managed pollinator species, experienced dramatic population declines, primarily as a result of the
accidental introduction in the 1980s of two bloodsucking parasitic mites. Between 1947 and 2005,
colony numbers nationwide declined by over 40%, from 5.9 million to 2.4 million. These losses have
occurred as demand for pollination services has soared for a number of fruit, nut and vegetable crops,
most notably for almonds. The NRC, the research arm of the National Academies of Science, is
chartered to provide independent objective analysis and advice on scientific matters of national
importance. Thus, with funding from the US Department of Agriculture, the US Geological Survey,
and The National Academy of Sciences itself, the National Research Council’s Board on Life Sciences
and Board on Agriculture and Natural Resources jointly convened an ad hoc committee to document the
status of pollinating animals in North America.
The committee was charged with determining whether, and to what degree, pollinators are experiencing
significant declines, identifying causes of such declines, and detailing the consequences of pollinator
declines in both agricultural and natural ecosystems. The committee was also asked to make
recommendations on research and monitoring needs and on conservation or restoration steps to prevent,
slow, or reverse potential decline. The committee addressed their charge by compiling and analyzing
published literature and evaluating expert testimony to determine the current state of knowledge on
pollinator status, to identify knowledge gaps, and to establish priorities for closing these gaps.
The Committee, comprising a group of 15 members from the U.S., Canada, and Mexico with expertise
encompassing ecology, population biology, ethology, genetics, botany, entomology, systematics,
agricultural economics, apiculture and conservation biology, quickly ascertained that there is an
extraordinary paucity of reliable data on pollinator populations. This dearth surprisingly applies even to
the honey bee, a species that has been semi-domesticated and managed for thousands of years. Honey
bees are in effect six-legged livestock that both manufacture agricultural commodities—honey and wax
—and, more importantly, contribute agricultural services—pollination. Close to 100 crop species in the
U.S. rely to some degree on pollination services provided by this one species—collectively, these crops
make up approximately 1/3 of the U.S. diet, including the majority of high-value crops that contribute
to healthy diets. Although economists differ in calculating the exact dollar value of honey bee
pollination to American agriculture, virtually all estimates are in the range of billions of dollars. It is
difficult in fact to think of any other multi-billion-dollar agricultural enterprise that is so casually
monitored.
Despite the enormous importance of the honey bee, methods for estimating the availability of bees for
pollination services are outdated and disturbingly inadequate. Since 1947, the National Agricultural
Statistics Service has conducted an annual survey of honey bees, but the focus of data collection has
been honey production and not pollination services; moreover, this assessment excludes hobbyist
beekeepers with fewer than five colonies, does not take into account colony movement between states,
and does not include assessments of the general health and vigor of the bees. Every 5 years, NASS
conducts a census that covers all farming operations with honey bees, including the 30% that do not
produce honey, but this census also does not assess pollination activities or colony health. Thus, the
magnitude of decline in honey bee abundance and efficacy, despite six decades of data collection, is
difficult to assess with precision.
That colony health is not regularly assessed is a serious deficiency. Bees in America have been beset of
late; colony collapse disorder is just the most recent of a seemingly unrelenting series of devastating
problems for the beekeeping industry. Introduced pests and parasites, microbial diseases, pesticide drift,
and competition with Africanized bees have all contributed to reductions in colony numbers since
NASS assessments began. Exacerbating the shortages created by the decline in numbers is the steadily
increasing demand for pollination services. Shortages were sufficiently acute that, in 2005, for the first
time since passage of the Honeybee Act of 1922, honey bees were imported from outside the U.S.,
primarily to meet the needs of the $2 billion almond crop. Importing bees, although necessary to meet
the demand for pollination, is an inherently risky enterprise in that it increases the chances of
introducing new pests and parasites. Even before CCD came to light, our committee estimated that, if
honey bee numbers continue to decline at the rates documented from 1989 to 1996, managed honey
bees will cease to exist by 2035. Historically, feral, or “wild,” honey bees have provided pollination
services to both natural and managed plant communities but no system is in place for monitoring their
numbers. Some evidence suggests that parasite infestations have all but eliminated feral colonies in
some areas, yet in the absence of systematic monitoring there is no certainty as to their distribution or
abundance.
Potential impacts of pollinator decline on U.S. agriculture
Why should reductions in the availability of one species of insect (one that can inflict a painful sting to
boot) be a concern of Congress? Even the complete disappearance of honey bees would not
fundamentally jeopardize food supplies in terms of calories because grains—the world’s primary
sources of dietary energy—do not depend upon animal pollinators. However, supplies of animal-
pollinated foods—most fruit, vegetable, and nut crops, which provide the bulk of vitamins and other
necessary nutrients in our diets—may well be dramatically affected. Among the most conspicuous
demonstrable consequences of honey bee declines in agriculture are the rising costs of producing bees
and hence rising costs for honey bee rentals, contributing in turn to rising prices for crops and
reductions in consumer welfare. Honey bee declines can reduce crop quality as well as yield. Rising
production costs combined with declining yields may lead economically marginal producers to switch
to crops independent of pollinators or to leave the industry altogether. Even before the advent of CCD,
financial impacts of honey bee shortages have materialized; varroa mites are estimated to have
increased honey bee colony rental fees by $30 million annually. Because bee pollination contributes to
so many different sectors of the agricultural economy, including the beef and dairy industries (via
pollination of clover and other hay and forage crops), disruption of the honey bee supply will likely
reverberate across the entire country. Free markets work well only when good information is available
and, without information on how to manage CCD, beekeepers will not be able to keep their bees alive.
If honey bees die in numbers large enough to compromise pollination,
markets will respond, but may do so in ways that are detrimental to the overall economy. Possible
outcomes include greater imports of bees from abroad (with associated risks of importing new pests),
higher prices of nuts, fruits and vegetables, reduced exports of major commodities, and increased
imports of cheaper fruits and vegetables from foreign markets where CCD is not a problem, all of which
will likely exacerbate the record U.S. trade deficit.
Short-term and long-term recommendations for honey bees
To address the problems in assessing honey bee decline, our committee recommended changes in data
collection methodologies to take into account colony use (i.e., honey production or pollination) and
colony seasonal losses. Moreover, our report recommended increased investment to encourage
innovative approaches to protecting honey bee health and improving genetic stocks of bees. Investment
in honey bee research has hardly been commensurate with the economic importance of this species.
Certain elements of contemporary apiculture have remained essentially unchanged for the past century;
in part, the lack of innovation reflects the relatively low priority accorded to honey bee research in the
agricultural sector. Appropriate investment requires minimally restoring lost positions in ARS for bee
scientists.
The Committee concluded its deliberations before Colony Collapse Disorder came to light. That honey
bees are experiencing losses on an unprecedented scale, however, was essentially predicted by the
report—over-reliance on one managed non-native species is inherently unstable. CCD has accelerated
the rate of colony loss, and beekeepers as well as growers need immediate relief. In view of the urgency
of this new problem, support in the form of new extramural funds would have the desirable effect of
rapidly expanding the now limited pool of investigators addressing the gaps in knowledge of honey bee
biology. Competitive funds offered through the USDA National Research Initiative (NRI) provide an
ideal mechanism for bringing new methods, new approaches, and new investigators into bee biology. In
particular, completion of the honey bee genome in October 2006 provides extraordinarily powerful new
tools for diagnosing problems, including CCD, and developing new management strategies. At the
moment, many investigators in the Colony Collapse Disorder working group are donating their own
time and money to solve this problem; such altruism, although befitting the social behavior of the honey
bee, is not sustainable long-term.
The 2002 Farm Bill is set to expire September 30 2007 and proposed 2007 legislation identifies
specialty crops as a high priority for research; many, if not most, of these specialty crops depend
heavily upon insect pollination, and pollinator sustainability should be a conspicuous component of
such research. At present NRI represents a tiny fraction of research funding within USDA; in
comparison with the proposed $1.38 billion intramural ARS budget, only $180 million is assigned to
the Cooperative State Research, Education and Extension Service (CSREES) for competitive grants
through NRI. Altogether, only 10% of USDA funding is competitive. No fewer than three NRC reports
attest to the value of competitive programs such as NRI in generating high-quality basic and mission-
oriented research (the 1989 study proposing the creation of NRI, Investing in the National Research
Initiative: A Proposal to Strengthen the Agricultural, Food and Environmental System, the 1994 study
Investing in the National Research Initiative: An Update of the Competitive Grants Program of the U.S.
Department of Agriculture and the 2000 report National Research Initiative: A Vital Competitive
Grants Program in Food, Fiber, and Natural Resources Research). As well, a permanent surveillance
program for parasites and diseases of the honey bee is clearly in the best interests of the nation; such a
survey could prevent the introduction of new pests and bring the U.S. into compliance with international
trade agreements. The request from APHIS for a National Honey Bee Pest Survey, declined last year, is
well worth reconsidering in the light of CCD.
Wild pollinators—putting pollen in more than one basket
It is an unfortunate consequence of benign indifference to the precarious nature of an overwhelming
reliance on a single species that few alternative actively managed species are currently available for use.
And despite evidence of their efficacy as crop pollinators, wild species are not being exploited to any
significant extent. While efforts to monitor honey bees are inadequate, efforts to monitor the status of
wild pollinators in North America are essentially nonexistent. Wild pollinators contribute in important
ways to crop pollination; in fact, pollination by native bees was recently estimated to be worth 3 billion
dollars annually in the US. In the Central Valley of California, for example, a wide variety of native
bees meet part or all of the crop pollination requirements for the region. Collectively, native bees are
more versatile than the honey bee; some species, including mason bees and bumble bees, are active
when conditions are unsuitable for honey bees, and others are capable of buzz-pollination—vibrating
the flower to induce it to release pollen—and thereby can service crops such as tomatoes, cranberries
and tomatoes more efficiently. Yet the status of wild pollinators is essentially undocumented for all but
the most charismatic species. There is reliable evidence that some North American pollinator species
have gone extinct, become locally extirpated, or have declined in number. At least two bumble bee
species, one of which is a crop pollinator, could face imminent extinction, and several other pollinators
have declined significantly. For some species, there is no evidence of population decline because their
populations have never been monitored over time; there is seldom a historical baseline with which
contemporary data can be compared.
The committee noted that, while systematic, thorough monitoring programs in Europe have revealed
dramatic declines in native pollinator abundance and diversity, there are no comparable North American
programs. The European experience demonstrates that monitoring is needed to document changes in
pollinator status. Additional recommendations for long-term pollination sustainability include
discovery surveys supported by the U.S. Geological Survey, the Fish and Wildlife Service, and other
agencies responsible for natural resource protection, to identify potential new pollinators. As well,
because of the importance of pollination as an ecosystem service in both agricultural and natural
ecosystems, federal funding agencies should recognize pollination as a cross-cutting theme in their
competitive grant programs and work together to integrate research that ranges from the genomics of
honey bees and the systematics and ecology of wild pollinators.
Conserving America’s pollinators will require economic incentives. Upcoming discussions of the Farm
Bill provide an opportunity to address this need. Through the Farm Bill, the federal government has an
opportunity to encourage state-level Natural Resources Conservation Service (NRCS) offices to
promote scientifically tested and approved pollinator-friendly practices for farmers participating in
USDA cost share programs (the Wildlife Habitat Incentives Program and the Environmental Quality
Incentives Program) and land retirement programs (the Conservation Reserve Program (CRP), the
Conservation Reserve Enhancement Program, and the Conservation Security Program (CSP)). CRP
should explicitly incorporate pollinator habitat in the environmental-benefits index used to evaluate
land parcel proposals and CSP should incorporate the value of pollinator habitat development into its
determination of the stewardship tiers that are the basis for federal payments. USDA cost-sharing, land
retirement, and production stewardship programs should be available to producers of all commodities
that depend on pollinators. The Xerces Society For Invertebrate Conservation (of which I am President)
has been working with the Natural Resource Conservation Service to incorporate native pollinators into
Farm Bill programs at both the National and State level and offers its time and expertise to
congressional staffers on language for the Farm Bill and its programs to accomplish this goal.
Pollination reserves and the American quality of life
Insuring the safety and security of our national food supply is an explicit national priority. Although it
is generally discussed in the context of vulnerability to attack and disruption from beyond our borders,
food security may well face a greater threat from within our borders--the overly optimistic deep-seated
conviction that pollination resources will always be available. The honey bee was critical to the success
of the earliest European colonists of the New World--English immigrant William Blackstone’s efforts
to grow apple trees in New England in 1623, e.g., were unsuccessful until honey bees were also
brought over to provide the necessary pollination. Four centuries later, American farmers remain
dependent upon this insect to produce their crops. Beyond agriculture, pollinators are crucial to
maintaining the quality of American life. They serve as keystone species in most terrestrial ecosystems
in that the services they provide allow most plants to reproduce and maintain genetic diversity. These
plants in turn provide food and shelter for animals; fruits and seeds produced by insect pollination are a
major part of the diet of approximately 25 percent of birds and of mammals ranging from red-backed
voles to grizzly bears. In some areas, pollinator-supported plant communities prevent erosion by
binding the soil—thereby conserving an important resource and keeping creeks clean for aquatic life.
Phalanxes of economists devote many hours to estimating and calculating our energy reserves but there
has been no comparable effort to calculate our pollination reserves. Human technological innovation
has not, in most cases, replaced or even improved upon animal pollinators and is unlikely to do so in
the immediate future. “The birds and the bees” remain an essential fact of life; as long as plants depend
on pollinators, so will people and it behooves us to shepherd them wisely.
Congressional testimony on CCD
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