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Invasive Arthropods in Agriculture
G. J. Hallman and C. P. Schwalbe, Editors
Science Publishers, Enfield, NH
2002, 447 pp.
Price: $99.50, hardcover
ISBN: 1-57808-172-6
U.S. agriculture is crawling
with pests and diseases introduced from other countries. Approximately 500
nonnative arthropods are serious pests in crops. Billions of dollars are lost
annually, in part, from lost crop production and greater management expenses
that often follow pest invasion. By recognizing the risks posed by exotic
arthropods, nations may wisely stiffen regulation of international trade to
limit new arrivals, but political expressions of concern about invasive species
can be mere ploys to change the balance of trade between nations. Beyond trade,
awareness of the impacts of invasive species on managed and unmanaged ecosystems
continues to grow. Within this context, editors Hallman and Schwalbe depict
past, present, and future challenges posed by exotic species in Invasive
Arthropods in Agriculture.
The text provides unique insights on the invasive
species problem from the perspective of regulatory entomology, where laws,
rules, and regulations provide additional tools for the integrated management of
introduced pests. In this case, management includes efforts to prevent new
arrivals, detect recent introductions, eradicate highly threatening species, and
implement areawide pest control programs, especially classical biological
control.
The text emphasizes challenges faced by the U.S.
Department of Agriculture, Animal and Plant Health Inspection Service (USDA,
APHIS). This agency strives to “protect the health and value of American
agriculture and natural resources” by “safeguard[ing] the health of animals,
plants, and ecosystems in the United States; and [facilitating] safe
agricultural trade” (USDA 2005). APHIS receives its authority from federal
statute (e.g., Plant Protection Act of 2000) but it must work within bounds
established by international agreements (e.g., the World Trade Organization
[WTO] Agreement on the Application of Sanitary and Phytosanitary Measures).
To achieve its mission, APHIS collaborates with
numerous partners within and outside the federal government. The USDA
Agricultural Research Service (ARS) provides many key collaborators, especially
for the development of quarantine treatments and new pest detection methods.
APHIS also works with university and federal scientists to refine methods for
pest risk assessment (the process used to evaluate the probability and
consequence of establishment by new pests) and improve biological control
practices. Hallman (from ARS) and Schwalbe (from APHIS) draw from this pool of
scientists and regulatory officials to demonstrate how responses to invasive
species have changed and are likely to evolve in the future.
Contributions from 28 authors are loosely organized
around four general topics. Chapters 1–6 and 9 deal with the “socio-political
facets” of arthropod invasion, including the history and status of current
regulations governing invasive species, costs associated with exotic pests, and
factors predisposing agricultural systems to invasion. Chapters 7, 8, and 11
address pest risk assessment. Chapters 10, 12–14, and 16 describe new methods
for quarantine, eradication, and control. Chapters 15, 17, and 18 focus
specifically on classical biological control, a special case in which arthropod
invasion can have tremendous advantages, if carefully planned and executed, or
disastrous consequences, if not. The final chapter, 19, concludes with thoughts
on the future of regulatory entomology.
In many agricultural systems, low genetic diversity
among crop plants, high resource input, and high degrees of disturbance create
simplified ecosystems that seem prone to invasion. The purported relationship
between species diversity and ecosystem stability provides the theoretical
underpinnings of this argument. Recommendations for greater agricultural
biodiversity would have been stronger had an alternative explanation been
addressed. For example, not mentioned in the text is Simberloff (2000) who
dismisses the diversity–stability relationship and suggests that a greater
frequency and density of new arrivals accounts for the larger number of
successful invasions in agricultural systems than in other ecosystems.
Preventing new introductions is recognized as the
ideal method to combat the invasive species problem, though this was not always
the case. From the 1700s through the establishment of the Department of
Agriculture in 1862, introduction of potentially valuable foreign plants was
encouraged. With these plants came new pests. The Insect Pest Act of 1905 and
the Plant Quarantine Act of 1912 marked the start of a growing awareness about
the invasive species problem and an appreciation for stronger regulatory
responses. The historical account in the book is outstanding. Domestic
regulations are placed into an international context with a clear, thorough
explanation of current WTO rules governing regulatory responses to exotic
species moved in international trade. Beyond trade, exotic species may arrive in
the United States through a mind-boggling diversity of pathways (e.g., living
beetles adorned with rhinestones brought as living jewelry!). These pathways are
thoroughly discussed.
Three particularly valuable chapters discuss a suite
of tools for pest risk assessment (e.g., phenology models, CLIMEX, GARP
analysis, process-oriented simulation models). Better predictions of where
exotic species might become established and which systems might be affected will
be essential to determine when and what regulatory actions are appropriate.
The discussion of costs
associated with introduced species is disappointing. This chapter is almost
identical to a paper first publishedBioScience (Pimentel et al. 2000),
but it is limited to excerpts relevant to arthropods and mollusks. The chapter
provides no new information. Interested readers would be better served to review
the original, which is the source for the widely quoted $137 billion anual
impact from all nonindigenous species in the United States.
The text is particularly suited to those who are
interested in but unfamiliar with regulatory entomology and could be the basis
for an interesting graduate-level colloquium. Elements of the book will also
appeal to anyone interested in historical entomology. A notable, but hardly
fatal, shortcoming of the book is a lack of contribution from the USDA Forest
Service. The Forest Service has been a partner with APHIS, for example, to slow
the spread of gypsy moth [Lymatria dispar (L.)] and to evaluate the
previously underappreciated risks posed by solid wood packing materials. Some
perspectives from this organization would have been an interesting complement to
a diverse group of authors who share the common goal of preventing damage from
invasive arthropods.
References Cited
Pimentel, D., L. Lach, R. Zuniga, and D. Morrison.
2000. Environmental and economic costs of
nonindigenous species in the United States. BioScience 50: 53–65.
Simberloff, D. 2000.
Foreword to reprinted edition of C. S. Elton. The ecology of invasions by
animals and plants. University of Chicago Press, Chicago.
USDA. 2005.
Animal and Plant Health Inspection Service strategic plan: 2003–2008 (updated
March 2005). US Department of Agriculture, Marketing and Regulatory Programs.
Available on-line at http://www.aphis.usda.gov/lpa/about/strategic_plan/APHIS_SPlan3-05.pdf.
Accessed 6 August 2005.
Robert C. Venette
North Central Research Station
USDA, Forest Service
1561 Lindig Street
St. Paul, MN 55108
venet001@umn.edu
American Entomologist
Vol. 52, No.3, Fall 2006
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