Draft import health standard for fresh table grapes for human consumption

All imported fresh table grapes need to comply with the general import requirements and meet basic measure requirements.

All fresh table grapes exported to New Zealand must be commercially produced.

We define commercial production as:

"A process (system) where activities, such as in-field monitoring, pest control activities, harvesting, cleaning, sorting, and grading, have been undertaken. These activities are carried out to minimise: 

• the presence of regulated pests; and 
• damage that may be a result of the presence of a regulated pest or that could expose the commodity to regulated pests."

The activities carried out in a commercial production setup are referred to as basic measures. MPI considers that the pests listed as being managed by basic measures will have their risk reduced to an acceptable level, not zero. These basic measures also help lower the risk of any other regulated pests that may be associated with table grapes but are not specifically listed. We used basic measures as a baseline for our risk assessment. This means we did not treat pests as a risk requiring additional measures on the pathway if they were already being adequately managed by commercial production practices.

Outcomes of basic measures (commercial production activities)

While identifying the hazards on table grapes, we reviewed pests listed on the existing grapes import health standards. We removed from the pest list those that were no longer considered a hazard and so did not pose a risk on the import pathway. 

Proposed exclusions of existing pests managed by basic measures [XLSX, 25 KB]

While identifying the hazards on table grapes, we reviewed existing pests that were managed by basic measures to reduce the risk on the pathway. We identified those pests for which this strength of measure (basic) should be retained.

It is important to note that these pests will not be listed in the IHS itself, but the list of pests associated with fresh table grapes and managed by basic measure can be found on PIER, our database of import and export requirements.

PIER – Product Import and Export Requirements

Note that some countries may have been added to this list of pests based on the evidence from our risk assessment.

While identifying the hazards on table grapes, additional pests not listed in current import health standards were identified as posing a risk on the pathway. Some pests (indicated with *) were not fully assessed because the initial evidence showed that risk would be reduced to an acceptable level by basic measures. For all remaining pests on the list below, further assessment was required to determine if basic measures would be sufficient.

All pests listed on the table below are proposed for inclusion and basic measures are considered to reduce the risk to an acceptable level. It is important to note that these pests will not be mentioned in the IHS itself, but the list of pests associated with fresh table grapes and managed by basic measure can be found on PIER.

PIER – Product Import and Export Requirements

Some species (for example scales and mealybugs) were assessed as a group since they have similar biology, ecology and are likely to have comparable impacts.

For an explanation of how we assess risk, see  details on risk assessment and impact ratings [PDF, 90 KB]

Targeted measures are justified where the risk posed by a pest is not sufficiently managed by basic measures alone. The following are a selection of measures that may be considered for managing pests requiring targeted measures:

Pest risk assessments determined that 2 mealybugs and 1 scale insect that are in some existing table grape import health standards do not require additional measures. These 3 pests are now proposed to be managed by basic measure requirements only.

Additionally, 8 spiders previously listed as venomous and requiring additional measures have been reassessed and now proposed for removal from the pest list as they are not a phytosanitary or human health risk.

During hazard identification, we reviewed existing pests that still require targeted measures to reduce the risk on the pathway. These pests are proposed to be retained on the IHS, requiring targeted measures. Note that some countries may have been added to this list of pests based on the evidence from our risk assessment.

After hazard identification, several new pests were flagged for further risk assessment to determine if additional measures were needed. Based on these assessments, the pests listed below are proposed to require measures beyond basic requirements.

Background and assessment

MPI has assessed the use of fumigation with ethyl formate + carbon dioxide as a new treatment to manage venomous spiders on imported table grapes. While previously used for vehicles and machinery since 2014, this is its first proposed use on fresh produce. The treatment was suggested by a trading partner, supported by research from De Lima (2009, 2015), which we reviewed to assess its suitability for quarantine use on grapes.

Summary of supporting studies

De Lima 2009

The study showed that fumigation with ethyl formate + carbon dioxide was effective against spiders found on table grapes.

However, the research noted that young spider stages (early instars) were more tolerant to the treatment, meaning they were harder to kill compared to adult spiders. It highlighted the need for sufficient dose and time to ensure that even the more resistant spider stages were managed.

Limitations: Few eggs and adults tested, gas-tight chambers in which the experiments were done are not reflective of real-world conditions.

De Lima 2015

The study found that applying fumigation treatments with ethyl formate + carbon dioxide during the cooling process of table grapes effectively controlled spiders while still maintaining grape quality for export. It focused on 1st–3rd instars. An increase in dose by 25% (50 g/m³) and duration to 2.5 hours was tested.

Limitations: Did not test eggs and adults, the authors did not explain why they used different doses and times.

What have we done about the identified gaps

To address the limitations identified in the 2009 and 2015 studies, we’ve refined the fumigation protocol to ensure efficacy across all spider life stages, including the more resistant early instars and adults.

Increased dose and exposure time

We’ve raised the ethyl formate concentration to 65 to 85 g/m³ and extended the treatment duration to 4 hours, based on efficacy data from the Vehicle/Machinery Pathway (VMP). This ensures a cumulative concentration-time (CT) value of 185 to 240 grams per hour per cubic meter (g/h/cm³) which is critical for penetrating spider silk structures and reaching spiders that may be hidden in grape bunches.

Temperature-adjusted schedules

Because fumigant efficacy is temperature-dependent, we’ve developed tiered treatment schedules:

• At 20°C, a lower dose (65 g/m³) is sufficient.
• At 15°C, the dose increases to 75 g/m³.
• At 10°C, the highest dose (85 g/m³) is required. These adjustments maintain consistent CT values across cooling regimes, ensuring reliable pest control even during cold-chain operations.

Defined loading factor

We’ve capped the maximum loading factor at 12%, aligning with the data from the chambers used in the experiments by De Lima. This ensures adequate gas distribution and prevents underexposure in densely packed grape boxes.

Minimum end-point concentrations

Each schedule specifies a minimum final concentration of ethyl formate and CO₂ (for example, 32.5 to 42.5 g/m³ EF and 3% CO₂), ensuring that fumigant levels remain lethal to spiders throughout the exposure period.

Proposed schedule

Ethyl formate (EF) fumigation:

• Apply a minimum dose of 65 g EF/m³ with 4% CO₂ at a temperature of 20 °C or higher for 4 hours. The treatment must achieve a CT of at least 185 g EF·h/m³, and end with a final concentration of at least 32.5 g EF/m³ and 3% CO₂. The maximum loading factor must not exceed 12%;
• Apply a minimum dose of 75 g EF/m³ with 4% CO₂ at a temperature of 15 °C or higher for 4 hours. The treatment must achieve a CT of at least 210 g EF·h/m³, and end with a final concentration of at least 37.5 g EF/m³ and 3% CO₂. The maximum loading factor must not exceed 12%; or
• Apply a minimum dose of 85 g EF/m³ with 4% CO₂ at a temperature of 10 °C or higher for 4 hours. The treatment must achieve a CT of at least 240 g EF·h/m³, and end with a final concentration of at least 42.5 g EF/m³ and 3% CO₂. The maximum loading factor must not exceed 12%.

Fruit flies are a high-risk pest group, and even an incursion could disrupt trade and cause large economic losses for New Zealand horticulturists. We propose managing fruit flies with the following specified measures, on top of basic measures.

Evidence supporting this proposal includes:

1. The fruit flies are recorded in association with table grapes.
2. Infestations may not be visible because the eggs and maggots will be inside the fruit.
   1. The complexity of the grape bunch makes it more difficult to detect fruit fly puncture marks.
   2. Fruit culling and general post-harvest handling is unlikely to remove all infested fruit.
3. The flies are likely to survive transit to New Zealand.
4. The flies have the potential to survive and complete development in table grape waste, i.e., discarded fruit.
5. The flies are likely to find suitable host plants in New Zealand.
6. The flies all have potential to establish in at least some parts of New Zealand due to climatic factors.
7. If a single fruit fly is detected, it has the potential to cause major negative economic impacts to New Zealand, largely due to New Zealand’s current pest-free status for tephritid fruit flies.
   1. Costs incurred to investigate an incursion or to respond to and eradicate an outbreak are high.
      1. For example, the B. tryoni (Queensland fruit fly) response in 2019 cost the New Zealand government approximately NZ$18 million.
   2. There would be financial and trade impacts on New Zealand.
      1. New Zealand horticulture exports are worth over NZ$6.7 billion (MPI, 2023).
      2. Trading partners are likely to impose export restrictions and/or additional phytosanitary measures for all fruit fly host material, which can be costly to implement.
         1. Market access loss at a cost of close to AU$100 million was recorded for the incursion of B. dorsalis (recorded as B. papaya) in north Queensland.
      3. Fruit fly establishment can cause high control costs for growers.
         1. Control costs due to fruit flies have been estimated at over US$7.5 million per annum in a single province (Western Cape) in South Africa (Barnes, 2016).
         2. Without control measures, direct damage of fruit and vegetable commodities can be as high as 100%.
8. The flies have the potential to cause significant damage to other plants in New Zealand, including economically important species such as citrus.
9. The flies have the potential to cause social impacts by affecting plants in residential gardens.

During hazard identification, we reviewed pests in existing IHSs that require MPI-specified measures applied to reduce the risk on the pathway. These pests are proposed to be retained in the IHS, requiring MPI-specified measures. 

An import health standard (IHS) specifies the requirements for importing risk goods into New Zealand from all countries with approved market access for that commodity.

To check the approval status and import requirements for specific commodities and countries, use PIER search.

PIER search

If a commodity is not approved from a certain country, you can find more information about requirements on our page 'Steps to importing fresh fruit and vegetables'.

MPI determines the strength of the measures required for pests based on the risk of entry and establishment in New Zealand, the potential consequences of establishment, as well as the uncertainty of the risk assessment.

The risk evaluation criteria include:

• current scientific evidence of pest biology and association
• relevant production processes and methods
• relevant inspection, sampling, and testing methods
• prevalence of pests and diseases in the country of origin
• relevant ecological and environmental compatibility (potential for long-term establishment in New Zealand)
• quarantine or in-transit treatment options
• potential economic and environmental consequences of entry and establishment (including the impact on cultural values).

MPI uses 3 different types of measures to manage pests and diseases: basic, targeted, and MPI-specified.

Pests managed by basic measures are those where commercial production practices (for example standard cultivation, pest control, harvesting, inspection, and packing) will reduce the population to an acceptable level, not zero.

Pests that are not sufficiently managed by basic measures require targeted measures, such as pest-free areas, pest-free places of production, end-point treatment, systems approaches or in-field pest control. Targeted measures are negotiated between New Zealand and the exporting country’s National Plant Protection Organisation (NPPO) and are captured in the export plan.

MPI-specified measures are required when the risk of entry and establishment of a pest is high and the consequence of establishment of a pest is severe. These are also included in the export plan and agreed on between New Zealand and the exporting country’s NPPO.

During the risk analysis stage, MPI identifies pests and diseases associated with the commodity (table grapes) and the import pathways covered in the IHS. Many pests may be associated with the grapevine plant (vitis vinifera) though not the commodity. For these pests that are unlikely to be found on the commodity, commercial production practices sufficiently manage the risk to the import pathway.

Other reasons for not being included as a risk pest for the commodity are: 

• the pest is already present and established in New Zealand
• updated scientific evidence concluding the pest is not associated with the commodity
• absence of the pest in the exporting markets
• non-regulated in the Official New Zealand Pest Register.

Official New Zealand Pest Register

Regardless of the strength of a measure, any viable regulated quarantine pest will be actionable at the border if intercepted. The same principle applies to pests that were not assessed in full. Although pests managed through basic measures are not listed in the import health standard, they will be listed in the Official New Zealand Pest Register, along with the actions that border inspectors should take if intercepted.

Official New Zealand Pest Register

Pest interception data is used early in the risk assessment when identifying pests that may be associated with the commodity and to inform the decisions on appropriate measures to manage the risk. Intercepting a pest frequently does not always mean stringent measures are required.

If a pest or disease of interest lacks sufficient evidence to proceed to the pest risk analysis, it is referred to our Emerging Risks System (ERS) team, who will actively monitor for new information and status changes involving this pest. When trade begins, we continue to monitor the interception data on the pathway to verify the measures in place are effectively managing the risk.

Before border clearance, all unaccompanied consignments of fresh fruit and vegetables may be sampled and inspected for the presence of pests, seeds, symptoms of disease, soil, and other non-conformities.

Under sampling option 1 (unless the importer has nominated a sample size), up to 6 weed seeds are acceptable in a consignment of 1,000 units (with 450 units sampled). If regulated weed seeds exceed this threshold, the consignment will be held at the border and the non-conformance documented. Quarantine officers will determine if remedial action, such as resorting, would be feasible. 

For more information on non-conformance and the alternate sampling options, refer to:  Guidance document – information on clearance of fresh fruit and vegetables for human consumption [PDF, 296 KB]

For further information on the sampling, inspection, and clearance processes at the border refer to the Guidance document – information on clearance of fresh fruit and vegetables for human consumption [PDF, 296 KB]

You can find an updated human health risk assessment of venomous spiders undertaken by Health New Zealand on its website.

Health risk assessment on poisonous spiders and the risks associated with the importation of table grapes – Health New Zealand