Quarantine Treatments and Systems Approach to Quarantine Security

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Quarantine Treatments and Systems Approach to
Quarantine Security

• Robert L. Mangan
• Crop Quality and Fruit Insect Research
• USDA-ARS, Weslaco, Texas, USA

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Quarantine Goal

• Prevent undesirable pest introduction
• Allow transport of commodities

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Importance of Quarantine Treatments

• Industrial nations need more variety in diet and
  improved nutrition

• Access to Markets for Fruits and Vegetables

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Quarantine security

• confidence that there will be no pest
  introduction capable of reproduction in an
  imported commodity

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Fruit Flies

• introductions are usually by transport of fruit
  with immature insects
• immature stages are usually clustered in fruit
• probit 9 requirement was devised to account for
  this clustering (Baker 1939)

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Probit 9 (as applied to quarantine of insects)

• 95 confidence that less than 0.00032 of treated
  insects will survive

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Historical Development of Systems Approach

• Withdrawal of quarantine treatments
• Ethylene dibromide 1984
• Methyl bromide phase-out 1992-present
• No acceptable quarantine treatments
• Cost, damage, new commodities
• Questionable need for quarantine treatments
• Infestation very rare
• Production and marketing system meets quarantine
  requirements

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the integration of those preharvest and
postharvest practices used in production,
harvest, packing and distribution of a commodity
which cumulatively meet the requirements for
quarantine security. E. B. Jang and H. R.
Moffitt (1994)
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Components of a Systems ApproachJang and Moffitt
1994 vs ISPM 14

• Pre-plant
• Pre-harvest
• Harvest
• Post-harvest treatment and handling
• Transportation and distribution

• Production
• Preharvest treatments
• Postharvest treatments
• Inspection and Certification
• Marketing and Distribution

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Pre-harvest vs Post-Harvest Treatments

• Pre-harvest treatments that control the pest
  usually reduce the number of fruit infested but
  not the number of pests per infested fruit.
• Post-harvest treatments usually kill individual
  pests in the fruit thus reducing the number of
  pests per fruit.

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A. ludens infesting Mangos- Baja CA. 1992
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Frequency Distribution A. ludens in Oranges
Baja Ca. Sur 1992
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Perform dose - response tests

• Statistically determine treatment that will
  achieve required mortality

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Confirmatory Tests

• Confirm effectiveness of propose treatment under
  conditions similar to commercial use.
• Data must be analyzed statistically to
  demonstrate confidence that required mortality
  level is achieved.
• Precise methods used in confirmatory tests must
  be approved by importing country.

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Experimental Hot Forced Air Unit USDA ARS Weslaco
Texas
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Experimental Unit Hot Water Treatment
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Heat Treatments
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Experimental Units Modified Atmosphere/Heat Treatm
ents
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Radiation Treatments Screwworm Sterilization Kerrv
ille Tx. 1946-51?
Fruit Irradiation Moore Airbase USDA PPQ
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Commercial Radiation Treatment Hilo Hawaii
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Fumigation Treatments
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Commercial Hot Forced Air Chamber Montemorelos
Mexico
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Dose-Response Treatments Controlled Atmosphere

• Pupal survival drops fastest at 10-15 days
  treatment.
• Variability is highest below 12 days.

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Number of Dead A. ludens Larvae after Exposure to
46C
Z. Grapefruit artificially infested with 25 live,
3rd instar larvae
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Radiation Dose-Mortality Pupae Anastrepha
obliqua Hallman 1997

• Mortality is sigmoid-maximum chnge in survival at
  5-gt10 g.
• Variance in mortality is highest at 50 mortality.

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Advantages of Post Harvest Quarantine Treatments

• Mortality is known from dose-response and
  confirmatory tests.
• Mortality rate is independent of other systems
  approach factors.
• At appropriate doses, variability in the system
  can be greatly reduced.

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Product Quality Certain yellow varieties of
mangoes, immature tissue converts starch to
fibrous material in place of sugar. Temperate
Fruits more sensitive to heat treatments
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Summary and Recommendations

• The systems approach was developed in as an
  alternative to post harvest quarantine
  treatments.
• Operation of post harvest treatments is
  independent of production, and marketing
  conditions, can be monitored at treatment
  facility and provides a known level of pest
  mortality.
• Post harvest treatments treat individual pests
  infesting the commodity and reduce variation in
  infestation rate per commodity.
• Many post harvest treatments for other purposes
  such as hot water dips for disease control, cold
  storage and controlled atmosphere for shipping
  and radiation for sanitation cause high pest
  mortality and should be considered as systems
  approach components.