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Michael J. Firko and Edward V. Podleckis
both native and exotic plant pests were discussed by Lockwood (1993) and
Carruthers and Onsager (1993), who examined these issues from different perspectives. Other arthropods have been introduced as crop pollinators; significant
international trade in nonhoneybee crop pollinators began during the past decade
with technical innovations for mass rearing of bumblebees (see discussion below).
Walk-through displays of live butterflies and other arthropods have become
popular worldwide. Currently, there are about 35 facilities in the United States
displaying live nonindigenous butterflies, and many more are currently in the
construction or certification phase. Most nonindigenous butterflies imported for
display are imported as pupae, many of which are collected from the wild or
“farmed” in open areas where host plants are cultivated to provide oviposition
sites for wild females. A variety of other taxa such as walking sticks, leaf cutter
ants, beetles, and cockroaches are also imported and displayed. Although strict
guidelines are in place to prevent escape of displayed organisms, escapes have
occurred. Importation of any of these organisms may lead to introductions of
associated species such as endo- and exoparasites, phoretic organisms, and
diseases.
International trade in agricultural commodities such as fresh produce is also a
potential pathway for movement of nonindigenous organisms. Vast quantities of
fresh produce are traded on international markets. Although the United States
enjoys a large agricultural trade surplus, millions of tons of fresh produce are
imported annually, especially during the winter. Virtually all the bananas consumed in the continental United States are imported, and for each of the 5 years
between 1992 and 1996, the United States has imported at least 30 million lugs
(boxes) of table grapes from Chile alone.
The responsibility for regulating most of the activities listed above falls on
federal and state government agencies. USDA-APHIS is the lead regulatory
agency for many of these issues. Regulating the movement of nonindigenous
organisms, primarily plant pests, via agricultural trade, passenger traffic, and
other human activities is the fundamental mission of PPQ. APHIS also considers
requests for release of a variety of organisms with potential plant pest characteristics including genetically modified organisms and nonindigenous biological control organisms and pollinators. USDA has deliberated the risk of introducing
nonindigenous organisms with agricultural trade for more than 100 years. However, over the past two decades, analysis of phytosanitary risks has attracted
increased scrutiny by governments, trading partners, and academic institutions
around the world. The advance of free trade agreements such as the General
Agreement on Tariffs and Trade and the North American Free Trade Agreement
has fueled the increased emphasis on pest risk analysis by removing tariffs as tools
for restricting trade while dictating that phytosanitary decisions be technically
justified. Technical justification is most often achieved through pest risk analysis
conducted according to accepted international standards (FAO 1996).
APHIS’ heuristic model for risk analysis (Gipson 1991) identifies three distinct
components: risk assessment, risk management, and risk communication. Risk
management includes consideration of risk mitigation measures and the decision-
Michael J. Firko and Edward V. Podleckis
both native and exotic plant pests were discussed by Lockwood (1993) and
Carruthers and Onsager (1993), who examined these issues from different perspectives. Other arthropods have been introduced as crop pollinators; significant
international trade in nonhoneybee crop pollinators began during the past decade
with technical innovations for mass rearing of bumblebees (see discussion below).
Walk-through displays of live butterflies and other arthropods have become
popular worldwide. Currently, there are about 35 facilities in the United States
displaying live nonindigenous butterflies, and many more are currently in the
construction or certification phase. Most nonindigenous butterflies imported for
display are imported as pupae, many of which are collected from the wild or
“farmed” in open areas where host plants are cultivated to provide oviposition
sites for wild females. A variety of other taxa such as walking sticks, leaf cutter
ants, beetles, and cockroaches are also imported and displayed. Although strict
guidelines are in place to prevent escape of displayed organisms, escapes have
occurred. Importation of any of these organisms may lead to introductions of
associated species such as endo- and exoparasites, phoretic organisms, and
diseases.
International trade in agricultural commodities such as fresh produce is also a
potential pathway for movement of nonindigenous organisms. Vast quantities of
fresh produce are traded on international markets. Although the United States
enjoys a large agricultural trade surplus, millions of tons of fresh produce are
imported annually, especially during the winter. Virtually all the bananas consumed in the continental United States are imported, and for each of the 5 years
between 1992 and 1996, the United States has imported at least 30 million lugs
(boxes) of table grapes from Chile alone.
The responsibility for regulating most of the activities listed above falls on
federal and state government agencies. USDA-APHIS is the lead regulatory
agency for many of these issues. Regulating the movement of nonindigenous
organisms, primarily plant pests, via agricultural trade, passenger traffic, and
other human activities is the fundamental mission of PPQ. APHIS also considers
requests for release of a variety of organisms with potential plant pest characteristics including genetically modified organisms and nonindigenous biological control organisms and pollinators. USDA has deliberated the risk of introducing
nonindigenous organisms with agricultural trade for more than 100 years. However, over the past two decades, analysis of phytosanitary risks has attracted
increased scrutiny by governments, trading partners, and academic institutions
around the world. The advance of free trade agreements such as the General
Agreement on Tariffs and Trade and the North American Free Trade Agreement
has fueled the increased emphasis on pest risk analysis by removing tariffs as tools
for restricting trade while dictating that phytosanitary decisions be technically
justified. Technical justification is most often achieved through pest risk analysis
conducted according to accepted international standards (FAO 1996).
APHIS’ heuristic model for risk analysis (Gipson 1991) identifies three distinct
components: risk assessment, risk management, and risk communication. Risk
management includes consideration of risk mitigation measures and the decision-