Combating the Medfly
case study was written by Anne Dawson, Sarah Hassenpflug, James Sloan,
Izumi Yoshioka with the assistance of Andrew Procassini, D.B.A.
Copyrighted by the Center for Trade and Commercial Diplomacy,
Monterey Institute of International Studies, Monterey, California, 1998.
The medfly poses perhaps the single greatest pest-related threat
to California’s multi-billion dollar agriculture export industry. The pest is responsible for the mass destruction of a wide
variety of crops, and continues to plague farmers and growers throughout
the world. The threat of
the medfly crossing international borders through trade in contaminated
agricultural goods has prompted governments to take often-severe
measures to prevent such a potential disaster.
Japanese government has maintained a particularly firm stance with
regard to standards and procedures governing the import of produce from
countries having any history of medfly appearances.
Although California agricultural exports to Japan play a
significant economic role on both sides, the Japanese government remains
committed to taking trade restrictive actions to reduce the possibility
of importing medfly-contaminated products.
As the most drastic measure, Japanese officials have indicated
that Japan would impose a comprehensive embargo on produce imports from
California due to increasing concerns over the presence of the medfly in
regions. U.S. federal and
state officials have responded to the intense foreign and domestic
pressures by implementing a number of major control measures designed to
rid the California agricultural industry of the menace of the medfly.
the intensity of U.S.-California efforts to combat the pest, the medfly
issue remains one of the key problems facing agricultural trade.
It has created hostile political divisions among members of the
government, farming, and scientific communities.
Government officials face pressures from foreign governments and
key interest groups, as the medfly continues to etch a lasting place in
U.S. agricultural trade history. This case study examines the medfly crisis in California,
from its beginnings in 1975, through the tumultuous 80s and 90s, and up
to the current status of the issue.
A: THE ORIGIN OF THE MEDFLY CRISIS
The history of California’s continuing war with the medfly is
comparatively short, spanning approximately twenty years to the present.
However, the conflict has proven to be extremely expensive and
highly controversial in many aspects.
The agricultural industry has long played a critical role in
California’s economy, prompting state and federal government officials
to take any necessary actions to preserve the continued health of the
industry. As the 20th century has progressed, California
produce growers have witnessed significant expansion in the market for
their agricultural goods. Accordingly,
the state farmers have become increasingly dependent on out-of-state
revenue sources for their produce.
Expansion of California’s agricultural export industry has
included increased exports to other states within the U.S., as well as
the opportunity to enter foreign markets such as Japan, South Korea,
Hong Kong, Taiwan, and China. With
reductions in some of the traditional trade barriers, and the
encouragement and assistance of local, state, and federal governments,
California's agricultural producers have recognized the value of the
blossoming foreign export industry and have realized significant
increases in the amount of exported produce.
While the health of the state agricultural economy has become
more closely associated with export revenues, producers have found
themselves subject to the product import standards and regulations of
the countries receiving California goods.
The plant quarantine laws adopted by each individual government
determine these rules and standards.
In Japan, the government has long had a reputation for
implementing particularly stringent regulations on agricultural imports
from abroad. The Japanese
system is characterized by rigorous product inspection and import
clearance procedures aimed at preventing the entry of any perceived
agricultural pests and contaminants into the local environment (see
Appendix A). Naturally, the
Mediterranean fruit fly is categorized as a particularly dangerous
exotic pest whose introduction to the Japanese environment could prove
highly detrimental to its domestic agricultural industry.
Should a medfly infestation ever occur in Japan due to
agricultural trade, the occurrence might extract both high economic and
political costs. Accordingly, the Japanese government has implemented
particularly strict standards with regard to the medfly. Costs are also
a consideration for the other side, as Japan has steadily evolved into
the largest export market for California producers. This fact, coupled
with the likelihood that other East-Asian governments such as Taiwan and
South Korea would most likely follow Japan’s lead in imposing
agricultural trade restrictions, makes Japan’s position on California
agriculture and the medfly issue an extremely important one for all
parties in the industry.
state and federal government agencies have responded to the medfly
threat by supporting an aggressive program designed to monitor for the
presence of the medfly. Officials have further implemented strict plant quarantine
measures to contain a medfly problem should one ever be discovered.
State and federal agencies maintain an intensive and often
controversial eradication program, incorporating the use of potentially
risky pesticides such as malathion, to handle any outbreak of the
destructive pest. Although
the cost of these measures can be enormous, the medfly programs are
viewed as essential to the preservation of both the agricultural
industry and the general health of certain state economies.
The medfly case has confounded policy makers due to its
policy makers have been confronted by pressures from the U.S. federal
government, individual U.S. state governments, foreign governments
(namely the Japanese), public interest groups, the scientific community,
various private interest groups, and the domestic agricultural industry.
All sides have engaged in strong and frequent dialogues in
pursuing their particular interests.
These political struggles among the opposing sides have erupted
into hostile exchanges in the courtroom and in the media.
With the steady increase in inter-state and international trade,
the current practices and procedures governing the California medfly
issue are the result of these intense foreign and domestic pressures.
In the course of addressing the unresolved concerns surrounding
the medfly, policy makers will continue to face significant political
and economic tension.
Mediterranean Fruit Fly
As one of the most destructive pests known to the agriculture
industry, the medfly can affect over 250 species of fruits, vegetables,
and other crops. The medfly
prefers fleshy fruits, such as peaches, apricots, and cherries, but may
infest virtually any fruit as well as most vegetables raised in
Female medflies destroy fruit by laying large numbers of
fertilized eggs beneath the skin’s surface of the host fruit or
vegetable. The eggs hatch
into larvae, which then consume the pulp of the fruit or vegetable.
The food product begins to rot, and usually falls to the ground.
The larvae then leave the fruit, burrow into the ground, pupate,
and finally reemerge as adult medflies (see Appendix B).
The entire life cycle may take as little as three weeks during
the warm summer months or can be as long as three months during the
The length of the life
cycle varies depending on the temperature of the environment and the
exact species of host fruit or vegetable that the pest chooses to
infest. These cyclical variations make the medfly a particularly
difficult insect to eradicate, as pesticides or other treatments cannot
always be precisely timed to have the maximum effect.
This results in the necessity for extensive measures to ensure
that the pest has truly been contained.
In every case, medfly-infested food products are rendered
inedible and completely worthless on the market.
The scope of destruction can be severe, with some farmers losing
their entire crops in a matter of days or weeks.
The medfly is believed to have originated in the tropical
climates of Africa. The
pest later invaded Europe, parts of the Middle East, South America,
Central America and Australia, eventually establishing itself in Hawaii
during the first decade of the 20th century.
The pest could not be eradicated due to the abundance of
potential host crops and the highly favorable climate conditions in the
twenty years later, the medfly made its first recorded appearance in the
continental U.S. The pest
was detected in several counties in the state of Florida.
After intense eradication efforts using arsenic-molasses sprays,
at an estimated cost of $7.2 million, the pest was officially eliminated
by the end of 1930. The
pest reappeared in Florida on three separate occasions between 1956 and
1963. The pesticide
malathion was used in the ensuing eradication efforts.
Texas became the next victim in 1966.
Here, malathion was again successfully used to eradicate the
pest. By this time,
California could only step up monitoring efforts and hope that the
medfly would not be found within its borders.
The medfly, however, did finally make its first appearance in Los
Angeles, California, in 1975 signaling the start of one of the most
complex trade cases in California’s agricultural history.
Medfly Eradication Program
In anticipation of future medfly discoveries within California's
borders, policy makers enacted an eradication program designed to
effectively deal with any potential medfly threat.
This program consisted entirely of measures to be applied in the
areas where medflies would be discovered, and did not include any
post-harvest treatment of the affected crops.
Once a medfly had been positively identified, government
representatives were to declare a state-of-emergency, calling for swift
actions to protect the important agricultural industry.
Policy makers could readily declare an emergency due to the
destructive reputation of the pest, given the fact that the medfly was
not a permanently established resident of California.
One of the key benefits to the emergency-based approach was that,
as an "emergency," state and federal government funds would
pay for the ensuing eradication program.
Thus, the industry would receive its much-needed protection from
the medfly without incurring state costs associated with eradicating the
a state-of-emergency had been declared, officials would respond by
placing a quarantine over a large area surrounding the actual discovery
sight. Under the quarantine
rules, no fruit would be allowed to leave the area.
In addition, the government would dispatch a ground-based
pesticide application force in order to conduct extensive ground
spraying using the pesticide malathion.
These measures would be accompanied by the release of hundreds of
millions of sterile male medflies.
These would hopefully mate with adult female flies, rendering the
female eggs infertile. It
was believed that collectively these measures would effectively
eradicate medflies in the affected area.
The quarantine would then be lifted, and business would continue
For most parties involved in the issue, these measures provided
an acceptable means of preventing medfly problems and, thus, allowed the
continuation of the lucrative agricultural trade.
Opposition, however, came from some public interest groups
expressing deep concern over the potential hazards of using malathion.
Nevertheless, industry interests prevailed and these methods were
utilized, as policy makers seemed determined to take any steps possible
to win a potential war against the medfly.
Only time would tell if these measures would be sufficient to
accomplish this ultimate goal.
The medfly was first discovered in California during 1975 in Los
Angeles. It is believed to
have arrived due to the illegal entry of contaminated fruit.
After the initial medfly detection, the problem quickly swelled
into an infestation. California
officials declared a state-of-emergency, and approximately 100 square
miles of land were placed under quarantine.
Under industry pressures, government agencies quickly initiated
the state’s first medfly eradication efforts.
The program involved the release of approximately 600 million
sterile male medflies and the heavy use of the pesticide malathion for
ground spraying. Total
costs of eradication were estimated at $1 million.
Officials declared victory in August 1976, lifting the regional
quarantine, ending extermination efforts, and finally announcing that
the medfly had been officially eradicated from the state of California.
The California agriculture industry emerged mostly unscathed from
the 1975 medfly infestation. The
economic impact to producers was relatively minor, and the successful
eradication efforts helped to establish government and market confidence
that California could effectively address the medfly issue.
As for the cost of the eradication efforts, this was paid for in
joint cooperation between the state and federal governments.
The industry paid nothing for the sterile medfly research and
release program or the extensive pesticide treatments.
Following the initial infestation of 1975, California’s
agricultural community experienced several years of peace with regard to
the medfly threat. However,
this calm was not to last, and the state found itself faced with a major
crisis at the start of the new decade.
In 1980, medflies were detected in several counties, spanning a
wide portion of the state. Monitors
detected four adult flies and one medfly larva in Los Angeles.
Officials responded with a declaration of a state-of-emergency,
spelling the beginning of a new round of eradication efforts.
These efforts consisted of the mass-release of sterile male
medflies and the use of malathion in heavy ground spraying.
Medflies were declared eradicated from Los Angeles in December of
Further north in California, the agriculture industry was, again,
embroiled in a major struggle with the formidable pest.
Hundreds of medflies were discovered over a wide range of
territory. Eight counties,
including Alameda, Contra Costa, Monterey, San Benito, Santa Clara,
Santa Cruz, San Joaquin and San Jose were affected.
The discoveries resulted in officials placing a quarantine over
the region, which eventually spanned approximately 530 square miles.
Eradication efforts were greatly expanded in response to the
crisis. Sterile male
medflies were released by the millions, and the government initiated an
extensive program of malathion spraying on the ground.
time, however, the usual eradication efforts did not appear to be
working. Monitoring traps
continued to turn up medflies, much to the chagrin of domestic producers
and state, federal, and foreign governments.
It became clear that the crisis could escalate if more serious
measures were not taken. California
officials responded by establishing the California Medfly Project in
June 1980. This was
followed by the creation of the Technical Advisory Committee, made up of
members of the scientific community who would assist in the anti-medfly
program efforts. These officials and committee members would soon face a
barrage of political pressures from all sides, as the medfly continued
its assault on California agriculture.
November 1980, the medfly problem in Northern California had not
subsided in the least. California
officials responded by initiating massive efforts to strip and destroy
fruits and vegetables in the affected areas, as the industry began to
show signs of severe panic. Domestic
producers called for more aggressive measures to combat the medfly.
Adding to the tribulations of the California agriculture
industry, out-of-state importers expressed deep concern over the crisis.
The Japanese government indicated that it was considering the
implementation of import restrictions should California be unable to
solve its medfly problem. Japanese
officials indicated that they would be unwilling to accept the increased
domestic risk of medfly contamination from imported California produce
and would be obligated to take actions accordingly.
California private industry parties and governing officials
agreed that this could be the beginning of a chain reaction in which
other foreign governments might impose severe trade restrictions on
California policy makers struggled with mounting foreign pressures, the
U.S. federal government expressed its alarm over the crisis. On November 24, 1980 the US Department of Agriculture (USDA)
issued its decision that the current medfly eradication efforts were
insufficient and called for an unprecedented program of aerial spraying
of malathion. A number of
state governments had already begun to exert pressures on California
industry members and policy makers, indicating that the future market
for California exports to their states might look increasingly grim
unless appropriate measures were taken.
These states supported the USDA's resolution that aerial
malathion spraying was in order.
November 27, officials from the California Department of Food and
Agriculture (CDFA) met with USDA officials to discuss the increasing
tensions surrounding the medfly issue.
The CDFA finally announced that it was seriously considering the
implementation of an aerial spraying program over much of the
quarantined area. This
announcement met with staunch opposition from several city governments
in the affected areas, as well as increased public interest group
pressure. Members of the
Technical Advisory Committee remained divided over the issue, while
local governments voted to prohibit the aerial spraying program.
with such a controversial decision, the CDFA agreed to postpone any
aerial spraying and, instead, relied on the massive eradication efforts
being conducted on the ground. Meanwhile,
the California State Department of Health Services issued a report on
the health issues surrounding the use of malathion.
The report insisted that the pesticide was a safe and effective
method for eradicating the medfly.
This allayed some of the fears associated with the aerial spray
program, as out-of-state pressures continued to mount over its
1980 came to a close, all of the parties involved waited to see if the
medfly would survive the combination of the increased eradication
measures and the approaching California winter.
The fact that medflies cannot tolerate cold weather conditions
led many scientists to speculate that the pest would not survive winter
in California. However, the
state is characterized by a highly desirable climate with comparatively
temperate winters. As the
medfly reemerged in the warmer months of 1981, it became evident that
the insect could survive the less-than-brutal weather conditions in
California. This discovery
turned the medfly into an even greater threat, calling for effective
eradication efforts to prevent it from becoming established in the
July, the Technical Advisory Committee decided that aerial spraying of
malathion might be a necessary step in the medfly eradication program,
releasing their decision in an emergency meeting on July 7.
The following day, the committee held talks with California
Governor Edmund "Jerry" Brown, Jr., strongly encouraging him
to initiate the controversial aerial spraying program.
Faced with political pressures from all sides, Governor Brown
delayed the decision and announced that the current ground based program
would be intensified. This
resulted in heated exchanges from all sides, as tensions mounted to
their highest level since the beginning of the crisis.
US Department of Agriculture (USDA) finally decided that more drastic
measures were in order. U.S.
Secretary of Agriculture John Block expressed the federal government’s
extreme dissatisfaction with CDFA medfly efforts, and issued the threat
that, unless California initiated the malathion aerial spraying program
immediately, the USDA would place a quarantine on the entire state. The announcement came on July 9, sending tremors throughout
California. Less than a
week later, the state governments of Florida, Mississippi, South
Carolina, and Texas threatened to impose unilateral quarantines on
certain California produce. Other
states followed, and California quickly found itself against a wall of
quarantine restrictions which could cause considerable damage to the
thereafter, foreign government officials claimed that they had seen
enough as well. Both Japan
and Mexico threatened to impose severe trade restrictions on much of
California’s produce exports. Japanese
officials were adamant that the California eradication and internal
quarantine procedures were unacceptable, and that unless the state could
handle its medfly problem, the produce export industry to Japan would
remain in extreme peril.
Thus, California officials conducted lengthy discussions over the
possibility of intensified internal quarantine measures.
In conjunction with the expressed concerns of the federal, state
and foreign governments, CDFA officials engaged in extensive
negotiations on expanding the medfly eradication program.
In addition to the ground efforts, officials suggested a new set
of guidelines involving both aerial pesticide spraying and post-harvest
treatment of exported crops. The
proposed post-harvest measures included mandatory produce fumigation
treatments using one of two extremely potent pesticides, methyl bromide
or ethylene dibromide. These
pesticides had the advantage of being both penetrating and extremely
lethal to any insect life in the produce.
However, methyl bromide damaged some of the fumigated fruits and
vegetables, reducing the market value of the crop.
And although ethylene dibromide caused little damage to the
fumigated produce, this pesticide’s use was to be phased out by 1983.
Another element of the proposed post-harvest treatment program
involved placing export produce into cold storage for up to ten days
prior to preparation for shipping.
This control method would prove particularly effective, as
medflies would not be able to endure the extended periods of low
temperature exposure. The
drawbacks of such an approach would be the tremendous expense of
constructing cold storage facilities to house all of the produce to be
fluctuations in the amount of produce harvests created additional cost
concerns. There would have
to be ample storage to accommodate produce exports from the rich summer
harvests, while many of the storage facilities would lie unused during
the less productive periods. The
extensive use of cold storage would involve both high initial production
costs, and continuing maintenance and operation expenses.
the new proposed quarantine treatment procedures, all export crops would
be submitted to both fumigation and cold storage prior to shipping to
out-of-state destinations. This
process would virtually eliminate the threat of inadvertently
transporting medfly-infested produce across borders.
However, some interest groups raised concerns as to the safety of
the current and newly proposed plant quarantine program.
Parties feared that the extensive use of malathion would not only
inflict severe environmental damage, but could potentially render the
food products unsafe. Coupled
with the newly proposed use of the notoriously potent pesticides, methyl
bromide and ethylene dibromide, critics suggested that these programs
used to address the medfly problem might entail significant health
risks. Thus, California
officials were faced with the unique dilemma of how to satisfy the
concerns of the domestic industry while simultaneously determining how
to respond to the restrictive pressures from foreign governments and
increasingly powerful interest groups.
Brown was obligated to release his decision over the medfly issue on
July 10, with the health of the California agriculture industry hanging
in the balance. Public
interest groups indicated that they would pursue measures to impeach the
governor should he decide in favor of the aerial pesticide spraying
program, while industry and government parties insisted that it was
necessary to preserve the produce export market.
As the medfly crisis intensified, the governor struggled to reach
his all-important decision on how best to handle the political and
Who are the important parties in the medfly
Define the political, economic, and/or social interests of each
of the involved parties.
Define the policy instruments available to each party in pursuing
Propose alternative strategies for achieving consensus on the
What viable policy
options can be implemented by California policy makers?
STUDY B: THE CHANGING CLIMATE OF THE MEDFLY CONTROVERSY
THE END OF THE '80s CRISIS
In the wake of the intense political pressures that
characterized the medfly debate, California's Governor Brown released
his decision on the eradication efforts on July 10, 1981. He declared that the state would commence with an aggressive
aerial spraying program of the pesticide malathion, as a necessary step
to preserve the state's agricultural economy.
Helicopters began spraying during the early morning hours of July
14, performing their missions from a secret landing base set up in a
Shortly after this initial application, officials launched an
all-out aerial assault on the medfly, using aircraft to spray malathion
over an area of approximately 1500 square miles.
Much of this territory included residential areas.
In addition, the state adopted the other proposed harsh
quarantine measures in an attempt to preserve California's produce
export market. In response
to the state's pest control problems, several U.S. states, including
Texas and Florida, and the foreign governments of Japan and Mexico
placed trade restrictions on California produce imports during the weeks
following the governor's announcement.
California officials and the domestic industry braced to see if
the intensified eradication efforts would eliminate the medfly and save
them from the economic peril.
By 1982, it appeared that the eradication efforts were indeed
successful in eliminating the destructive pest.
Only two medflies were discovered during 1982.
As a result of the state adopting the strict quarantine measures,
the industry was spared from lasting export restrictions. Finally in September 1982, supported by scientific evidence,
the USDA and CDFA declared the medfly to be effectively eradicated from
the state of California. The
victory came at a significant cost.
Officials estimated that the total expenditures for eradication
efforts alone amounted to approximately $100,000,000[iii].
With this announcement of victory over the medfly, all
eradication efforts and quarantine procedures were halted, the state
industry slowly resumed its normal operations.
Following the crisis of the early 80s, the medfly made periodic
appearances in California.
In 1984, two medflies were discovered in baited traps. However,
it appeared that these were isolated incidents, which did not suggest a
medfly infestation. Two
more were discovered in 1986, sparking renewed concern over the volatile
issue. Then in 1987, the
medfly made its presence felt in much greater numbers, resulting in the
regional quarantine of the Los Angeles area and renewed aerial
application of malathion. 1988
proved just as problematic, with the discovery of 54 medflies in the Los
Angeles area. This resulted in further area quarantines and continued
aerial pesticide spraying.
THE MEDFLY CONTROVERSY IN THE
medfly problem escalated in the 1990’s.
From 1989 to 1994, medflies were discovered every year in several
areas. 1989 was the
year in which the most medflies were ever found in California, totaling
260. On July 20, 1990, one wild Medfly was discovered in a trap
near Dodger Stadium in Los Angeles.
The discovery prompted an eradication program that grew to
encompass 21 treatments in Los Angeles, Orange, San Bernardino, and
Riverside counties. 536 six
square miles received aerial applications of malathion bait.
On November 8, 1990, the CDFA secretary officially ended the
eradication program and quarantine.
1991 one wild Medfly was found near the Koreatown area of Los Angeles.
An additional wild Medfly was found about 15 miles to the east of
San Gabriel. Eradication
methods used included high density yellow panel trapping, ground
malathion and bait sprays of all properties within 200 meters of each
fin, and sterile medfly releases over a 26-square mile area at a rate of
approximately 30 million per week between October 1991 and August 1992.
1992 and 1993, 202 wild Medflies were found in Pasadena, Jefferson Park,
Duarte, Inglewood and Griffith Park.
Consequently, eradication responses were initiated around all
multiple finds. The methods
used included intensive trapping, ground malathion and bait treatments,
and sterile medfly releases.
1993, one mated female Medfly was discovered in Corona, Riverside
County. Trapping and ground
application of malathion bait began.
On January 21, 1994, Governor Pete Wilson issued an emergency
declaration authorizing the state government to do everything necessary
to alleviate the infestation. Eight
aerial applications of malathion bait and intensive trapping followed.
On July 5, 1994, the CDFA secretary declared eradication and
lifted the agricultural quarantine in Corona.
March of 1994, following the recommendations of the International
Scientific Advisory Panel, CDFA began a basin-wide sterile Medfly
release program over a 1,464-square-mile area in Los Angeles, Orange,
and San Bernardino counties. The
program released a total of 250,000 sterile flies per square mile per
week over the entire area, and released an additional 250,000 sterile
flies over those areas where wild flies were found in 1994 (core areas).
The program was completed in March of 1996.
After finding two mated female Medflies in Ventura County in
1994, an aerial malathion and bait treatment program in the Camarillo
area of Ventura County was initiated on October 6, 1994.
Fourteen aerial applications were completed in a 16-square-mile
area, the last occurring on May 23, 1995.
On August 1, 1995, after ten months of treatment, the CDFA
secretary lifted the agricultural quarantine in Camarillo.
As the Medfly became a more frequent visitor to California, the
concern for the economic ramifications continued to grow.
In 1991, James Siebert and Vijay Pradhan, agricultural economists
at the University of California at Berkeley, conducted a study analyzing
the economic impact of the Medfly on California agriculture. It was based on a 1981 study and focused on many of the same
areas in determining the costs of dealing with Medfly infestations.
Primarily, the expenses incurred through damaged produce, Medfly
control, and post-harvest quarantine were estimated.
The CDFA, in 1990, identified 35 commodities as possible Medfly
hosts. If accurate, the
Medfly could have potentially affected $6.528 billion worth of
California produce, of which $1.708 billion was to be exported.[iv]
The impact on the value of production and export markets,
therefore, was definitely significant.
(see Appendix C)
Facing such tremendous losses, California officials recognized
the need to address Medfly infestations.
One method utilized was that of controlling it while the produce
was still in the fields. The
total field costs, including the expense of the pesticides as well as
that of their application, were estimated to range from $349.6 million
to $731.9 million.[v]
(see Appendices D and E)
An alternative to the sole use of pesticides, known as Integrated
Pest Management, combined the use of non-pesticidal methods of control
with limited use of pesticides. This
practice became prevalent in the 1980’s and could not be overlooked
when discussing the costs of controlling the Medfly. However, calculating the actual costs of this program during
that time was difficult as the strategic combinations were as varied as
the numbers of growers and crops were.
Even with these efforts, controlling the Medfly was not
included in the 1991 study, were the estimated costs of a post-harvest
quarantine system. The two
options for treatment were the use of methyl-bromide and cold storage.
These, however, were not without their own negative consequences:
shortened shelf-life and deterioration of produce quality; costs
incurred in upgrading or building new facilities; and increased
transportation costs to and from quarantine sites.
The total expenses of this post-harvest treatment were estimated,
in 1991, to be $109.5 million. Another
$25.7 million was the estimated damage resulting from the treatment.
In total, the quarantine phase was expected to cost $135.3
(see Appendix F)
New Twist to the Medfly Problem
By 1994, Japan had had enough. The consistent and seemingly worsening
occurrences of medfly attacks in California caused Japan to threaten an embargo on California fruits, based on which fruits were affected. The embargo never occurred, as the Japanese government was satisfied with the CDFA’s eradication methods, but the threat was a symptom of an increasingly serious problem for California growers.
The Medfly problem in the1990s was aggravated further when in
1990 James Carey, an entomologist at the University of California Davis,
went before a session of the California State Assembly and presented his
theory that the medfly was already established in California and had
become a permanent resident[vii].
Carey proposed that the medfly appearances experienced in the
1980’s were not isolated events but rather reappearances of the same
small population established in California.
According to Carey, the medfly probably first came to California
before the turn of the century, but the population was so small that it
took until 1975, when the first medfly was discovered in California, to
become detectable. Since
that first sighting in 1975, the medfly has appeared every year from
1980 to 1994, except for 1983 and 1985, and the areas in which it has
appeared have widened every year. Carey
sees this as evidence the already established medfly population is
slowing spreading north and east across California in a relatively
straight-line pattern and hindered only by mountain ranges.
Carey says that “these steady, near-straight-line progressions
can’t be random introductions from people carrying in infested fruit;
if that were the case, there’d be medflies scattered all over the
map.” Instead, new medfly
outbreaks almost always appear in roughly the same neighborhoods as
The California Department of Food and Agriculture has
continuously maintained that each appearance of the medfly is an
isolated incident and that it keeps being reintroduced to California by
people shipping or carrying in infested fruit illegally.
Hawaii has been sited as a major source of infested fruit.
However, a small group of entomologists from Florida to Hawaii
have conducted tests in which they study the DNA of medflies captured in
California and compare them to the DNA of medflies from areas where the
medfly is already established to determine their origin.
They do this by looking for a banding pattern that would
differentiate populations by country or region.
They use an enzyme that cuts the mtDNA every six base pairs.
In one particular analysis of 14 banding patterns, they
distinguished two distinctive haplotypes in their medfly samples.
Those from Hawaii and Venezuela exhibited one haplotype, whereas
samples for Argentina, California, and Guatemala showed the alternate
haplotype. That the
Hawaiian haplotype was not present in the California medfly provides
strong evidence that Hawaii was not the geographic source of the
This finding also supports Carey’s theory that the medfly
population came from South America back in the nineteenth century.
In addition, Carey notes that when USDA Plant Protection and
Quarantine personnel inspected baggage coming into major international
airports in the period 1985 through July 1990, relatively few medflies
were discovered. In fact,
there were only five medfly interceptions in all three California
international airports during the 5-to 6-year period: four in Los
Angeles, one in San Francisco, and none in San Diego.
Yet in the same period there were over 4000 interceptions of
other fruit flies[x].
This evidence, in addition to the results of the DNA testing,
presents a strong case in support of Carey’s theory.
Despite the evidence that Carey has presented, the CDFA maintains
that the medfly is not a permanent resident and has not become one
because of the efforts of the CDFA and the USDA to eradicate it each
time it appears. Says CDFA
entomologist Bob Dowell, “We believe the insect has invaded and begun
to colonize, but we find it and eradicate it.
That’s followed by another invasion and we start all over
The CDFA has every reason to maintain this position.
There is a lot at stake if the medfly is officially declared a
permanent resident of California.
One of the biggest concerns surrounding this issue is the welfare
of the international market for California fruit, especially in Asia.
The medfly is already established in many countries in Europe and
South America, so there is not a threat of losing these markets.
However, it has not reached countries like Japan, Hong Kong,
Korea and Taiwan. The CDFA is especially concerned about Japan, which provides
the largest market for exported California produce. In 1994, the fear of losing the Japanese market became a
definite possibility. Japan
threatened an embargo on California produce when the medfly reappeared.
The international community had been concerned about the previous
medfly appearances in the late 1970’s and the 1980’s, but this was
the first time an embargo was threatened.
CDFA officials believe that Carey’s theories may have
contributed to this threat.
What is especially troubling to the CDFA is that since Carey
first presented his theories in 1990, he has not presented any new
evidence to back his theories up. But
at the same time, he has caused panic in foreign markets.
In the summer of 1992, assistant director to the CDFA Isi
Siddiqui faced a roadblock in China, a potentially $200 million market
for California produce, based on the Chinese fear of Carey’s
presentation of the medfly threat.
at stake for the CDFA is the federal support it currently gets for
medfly eradication procedures. Each
time a medfly outbreak occurs, the CDFA declares it an emergency
situation. This makes them eligible for additional aid from state and
federal emergency funds. If
the medfly were determined to be a permanent resident of California, the
CDFA could no longer declare each appearance an emergency and would lose
this funding. The burden
would then be laid on the growers, who maintain a powerful lobbying
presence in Sacramento. Carey
claims that these political-economic issues influence the CDFA, so it
will therefore never accept his theories.
CDFA is also facing opposition from the residents of the affected
counties in their eradication efforts as people fear the potentially
severe side effects of exposure to malathion spraying.
There have been reports that some people who have been exposed to
malathion experienced problems in their nervous and respiratory systems.
Malathion can also peel the paint off a car.
In 1990, Ventura County filed an injunction against the CDFA to
prevent malathion spraying, which delayed eradication and resulted in
the end to the sweeping spraying of malathion by helicopters.
In 1992, 10 percent of the residents in the affected areas
refused to allow access to their backyards for spraying.
The CDFA maintains that malathion is safe if used properly, and
the reason it harms the paint on cars is because it is corn-starch
medfly has been eradicated after each appearance and the threat from
Japan has dissipated, but how would Japan react if the medfly residency
theory were proven? Given
the already strict import procedures (See Appendix A) for produce in
Japan to eliminate pests that already exist in Japan, as well as the
devastating effect the medfly has on fruit, it is possible that Japan
would place an indefinite embargo on California fruit.
Japan has already done this to some countries, such as Mexico,
Brazil and Spain where the medfly is definitely established.
If Japan did this, other Asian countries would be likely to
follow suit. The result for California agriculture would be disastrous.