Although ISPM No. 4 (Requirements for the establishment of pest free areas) provides the general guidance on the establishment of PFAs, the need for additional guidance on establishment and maintenance of PFAs for fruit flies was recognized. This standard describes the requirements for establishing and maintaining a FF-PFA. The target pests for this standard include insects of the order Diptera, family Tephritidae.
The establishment of a FF-PFA and its recognition by trading partners implies that no other phytosanitary measures are required for the target species of fruit fly for host commodities sourced from within the FF-PFA, if the phytosanitary integrity of the host commodity is maintained throughout harvest, sorting, storage, packaging and transport.
A pest free area is "an area in which a specific pest does not occur as demonstrated by scientific evidence and in which, where appropriate, this condition is being officially maintained" (see ISPM No. 4).
Fruit fly pest free areas may occur naturally or following the successful implementation of pest eradication programmes (see ISPM No. 9: Pest Eradication programmes). The decision to establish a FF-PFA is made by NPPOs based on technical and socio-economic feasibility.
Technical factors to consider in determining the feasibility of establishing a FF-PFA in a country may include components such as: pest population levels, geographic isolation, climate, geography and availability and feasibility of methods for pest eradication. All the procedures used for establishment and maintenance of the FF-PFA should be documented, audited and endorsed by the NPPO.
In areas where geographic isolation is not considered adequate to prevent reinfestation of a FF-PFA or where there are no other means of preventing fruit fly movement to the FF-PFA, a buffer zone will need to be established. Some of the factors which should be considered in the establishment of a buffer zone include:
pest suppression techniques which may be used to reduce the fruit fly population including: selective insecticide bait spraying, sterile insect techniques, male annihilation technique, biological control, mechanical control;
the target fruit fly species and its biology, host availability, cropping systems, natural vegetation including adjacent forest or natural ecosystems, climatic conditions;
the geographic features of the area under consideration; and
the proximity of large urban areas that may make the control of fruit fly species of economic concern difficult and/or costly.
NPPOs should have in place adequate infrastructure and trained personnel available to identify captured specimens of the species in an expeditious manner. Where expertise is not available within the country the NPPO may identify a competent authority in another country to undertake identifications.
An important factor in the establishment and maintenance of FF-PFAs is the support and participation of the people living within the FF-PFA, individuals that may travel to or through the area, and other parties with interests in the area. The FF-PFA status can be maintained only if there is no introduction of target species through the movement of infested fruit. The public and stakeholders should be informed of the importance of establishing and maintaining the pest free status of the area. This awareness may include information on exotic species of quarantine concern. The programme helps to achieve compliance with the phytosanitary measures for the FF-PFA. It may include the following elements:
penalties for non-compliance with FF-PFA requirements.
All procedures used in the establishment and maintenance of a FF-PFA should be adequately documented. The procedures should be reviewed and updated regularly. Any corrective measures implemented to refine or re-establish a FF-PFA should also be documented.
Records of all procedures (such as surveillance, detection and response activities) undertaken in the establishment and maintenance of a FF-PFA should be retained for as long as possible. Such records may be used to build confidence in the systems implemented and should be made available to trading partners on request.
The FF-PFA programme, including the surveillance procedures (both trapping and fruit sampling when used), regulatory control, and corrective actions should comply with the documented and approved procedures. The effectiveness of the programme should be monitored by the NPPO and/or trading partner, as appropriate, using quality assurance procedures.
The procedures should also record formal delegations of responsibilities to key personnel, for example:
management representative - officer with defined authority and responsibility to ensure the systems/procedures are implemented and maintained appropriately;
nominated reference entomologist - officer with responsibility for the authoritative identification of fruit flies to species level; and
other formal delegations where appropriate.
All operational activities should strictly follow documented and approved procedures, and will be subjected to both internal and trading partner audit as appropriate.
The following characteristics of a FF-PFA should be considered in the determination of a specific area:
buffer zones (where necessary).
The following should be developed and implemented:
the establishment of buffer zones where necessary.
A regular survey programme for fruit flies of economic concern should be established and implemented. Generally it is considered that trapping, using an established trapping network throughout the FF-PFA, is sufficient to determine fruit fly absence or presence in an area. Should a population of fruit flies be detected during the establishment phase using lure-responsive trapping methods, fruit sampling may be used to provide additional information regarding the level of infestation and location of the infestation.
For species that are non-responsive to specific pheromone lures, fruit sampling may be used during the establishment phase of a FF-PFA. However, non-pheromone lure based traps (i.e. food-based traps) are generally used for large scale monitoring of FF-PFAs where non-pheromone lure responsive fruit flies are to be monitored. Should a population of non-pheromone lure responsive fruit flies be detected during the establishment phase, fruit sampling may be used to provide additional information regarding the level of infestation and location of the infestation.
Surveillance should be undertaken for at least 12 months in the FF-PFA, or a period agreed to by consultation with prospective trading partners, using specific trapping and fruit sampling procedures throughout the potential FF-PFA. Trapping and sampling procedures should be applied to both commercial and non-commercial host material. These procedures are used to demonstrate that the pest is not present in the potential FF-PFA. There should be no detections (adult or immature stages) of the target species during the survey period. Trapping and/or fruit sampling techniques adopted should follow established protocols for the target species of concern.
This section contains general information on trapping procedures. There are long-established trapping systems that have been used to survey fruit fly populations.
Trap type and lures
Traps used for fruit flies depend on the target species, the season and the nature of the attractant. The most widely used traps contain para-pheromone or pheromone lures that are male specific. Lures for capturing non-pheromone responsive species or females of both lure and non-lure responsive species are based on food or host odours. Historically, liquid protein baits have been used to catch a wide range of fruit fly species. Liquid protein baits capture both females and males, with a slightly higher percent of females captured (though identification of the fruit flies can be difficult owing to premature decomposition of trap catches caused by the liquid nature of the trap). Dry synthetic protein baits which are commonly used for some fruit fly species are female biased. These baits tend to capture fewer non-target organisms and when used in dry traps prevent decomposition of captured specimens.
Trap density
Trap density is critical for fruit fly surveys and will be dependant on the target fruit fly species, trap efficiency and biotic and abiotic factors. Density may change depending on the programme phase, with possibly different densities being required during the establishment and maintenance phases of the FF-PFA. Trap density will also be dependant on host occurrence from production to marginal areas and the risk associated with potential points of entry.
Trap deployment
In FF-PFA programmes an extensive trapping network should be deployed over areas where host plants are found. The trapping network layout will depend on the characteristics of the area, host distribution and biology of the fruit fly of concern. One of the most important features of trap placement is selecting a proper trap location and trap site within the selected host tree. If low growing host plants (strawberries, cucurbits etc.) are to be monitored or the availability of suitable host trees is limited, traps should be placed as close as possible to the canopies of non-host shade trees or an artificial equivalent, 1-2 metres above the ground.
Traps should not be hung below the foliage canopy of host trees, and should be a minimum of 1 metre above the ground. If more than one type of trap is deployed at a trapping site (e.g. two different lure traps), the traps should be separated by a minimum of 3 metres and should not be deployed in the same host tree.
Geographic positioning systems (GPS) and global information systems (GIS) are useful tools for management of a trapping network.
Preferred host(s) and fruit maturity
Trap location should take into consideration the presence of the preferred hosts of the target species. As the pest is associated with mature fruit, the location of traps should follow the sequence of fruit maturity in host plants. Consideration should be given to commercial management practices in the area where host trees are selected. For example, the regular application of insecticides (and/or fungicides) to selected host trees may have a false-negative effect on the trapping programme.
Trap servicing
The frequency of trap servicing during the period of trapping will be dependent on:
environmental conditions.
It is important that lure material does not contaminate the external surface of the trap, nearby soil or plant material. It is equally important to ensure that there is no cross-contamination between lure types, or between lures and other chemicals.
Trap replacement
Traps have a definite working life, and the replacement of traps should be undertaken periodically based on the expected longevity of the trap in the particular environment. The condition of each trap should also be examined during trap servicing and inspection activities, and where applicable (e.g. signs of deterioration), traps should be replaced.
Trap inspection
The frequency of inspection during the period of trapping will depend on the level of fly activity, response periods required at different times of the year, relative number of target and non-target fruit flies expected to be caught in a trap, and the need to prevent specimens from deteriorating and thus preventing identification.
Record keeping
All trapping and servicing data should be recorded. Records should be kept up-to-date and be readily available.
With fruit flies that are not responsive to traps, the following factors should be considered if fruit sampling is to be used as a surveillance method. It should be noted that fruit sampling is particularly effective in small-scale delimiting surveys in an outbreak area. However, it is labour intensive, time consuming and expensive due to the destruction of fruit.
Host preference
Fruit sampling should take into consideration the presence of hosts of the target species. Sample fruit should be targeted based on maturity and apparent signs of infestation.
Targeting high risk areas
Fruit sampling should be targeted to areas likely to have presence of infested fruits such as urban areas, abandoned orchards, rejected fruit at packing houses, fruit markets and sites with a high concentration of primary hosts.
Sample size
Factors to be considered include:
the sample size should be based on a statistical study to ensure samples provide an adequate level of confidence of fruit fly detection within the host commodity;
the sample size, the number and weight of fruits per sample should be planned based on the availability of primary host material in the field; and
samples may include fruit with infestation symptoms on a tree, fallen fruit or rejected fruit (at packing facilities) if this is scientifically accepted.
Procedures for holding fruit
Fruit samples should be brought to a facility for holding, fruit dissection, pest recovery and identification. Fruit should be labelled, transported and held in a secure manner to avoid contamination and mixing of fruit. Where it may be necessary for eggs/larvae to be grown out for identification purposes it is important that the fruit be held in suitable conditions to maintain the viability of immature insects.
Record keeping
All fruit sampling data should be recorded to permit trace-back of detections. Records should be kept up to date and be readily available.
Regulatory movement controls for regulated articles are required to prevent the entry of target pests into the FF-PFA. These controls will depend on the assessed risks (after identification of likely pathways and regulated articles) and may include:
listing of the target fruit fly species on a quarantine pest list;
listing of regulated articles for which movement is controlled;
publishing of regulations if necessary, including restriction of the movement of certain products within areas of a country or countries;
specification of import requirements into a country or area; and
inspection of regulated articles and examination of relevant documentation and, where necessary, application of appropriate non-compliance actions (e.g. treatment, reshipment or destruction).
Additional information may be useful during the establishment phase of FF-PFAs. This may include:
historical records of detection, biology and population dynamics of the target fruit fly species, and previous survey activities for the designated target fruit fly species in the FF-PFA;
the results of previous actions taken following detections of fruit flies in the proposed FF-PFA;
records of the commercial production of host crops in the area, an estimate of non-commercial production, and the presence of wild host material; and
lists of the other fruit fly species that may be present in the FF-PFA.
The NPPO verifies the fruit fly free status of the area (see ISPM No. 8: Determination of pest status in an area) by checking the compliance with the procedures set up in accordance with this standard (surveillance and regulatory controls). The NPPO declares the establishment of the FF-PFA and notifies trading partners as appropriate.
Following the establishment and declaration of a FF-PFA, this status should be maintained. The NPPO should continue to administer all management and operational aspects associated with the FF-PFA (for example, surveillance activities and regulatory controls).
After verifying and declaring the FF-PFA, the official surveillance programme should be continued at a level assessed to be required for maintenance of the FF-PFA, for as long as the FF-PFA is operational. Regular (for example monthly) technical reports of survey activities should be generated. This may be the same as for surveillance procedures during the establishment phase with differences in density and trap locations dependent upon the assessed level of risk of introduction and establishment of the target fruit fly species. It is likely that there will be lower densities required in commercial production sites and higher densities at points of entry and urban areas.
Additional surveillance within the declared FF-PFA may be required for non-target exotic fruit fly species of economic concern.
These are the same as for establishment. See section 3.2.2.
The NPPO should have plans for corrective action that may be implemented if the target pest is detected in the FF-PFA (see Annex 1). This should include:
criteria for the declaration of an outbreak/incursion, and the determination of the outbreak area and suspension area/s within the FF-PFA;
criteria for reinstatement of a FF-PFA suspension area following an outbreak;
procedures for responding to post-harvest interceptions, including interceptions by trading partners in imported host material;
criteria for initiating further surveillance;
rapid identification of target fruit fly species;
the rapid implementation of delimiting survey/s (trapping and fruit sampling);
eradication measures; and
notification of corrective actions to trading partners as appropriate.
A corrective action plan should be initiated within 72 hours of the detection, if previously determined criteria for the initiation of corrective action are met.
Similar corrective action plans may be prepared for non-target exotic fruit fly species.
The status of the FF-PFA will change when an outbreak of the target pest occurs or procedures are found to be faulty.
If the criteria for an outbreak are met, this should result in the implementation of the corrective action plan as specified in this standard and immediate notification of trading partners (see ISPM No. 17: Pest reporting). The whole or part of the FF-PFA may be suspended or terminated. Where a suspension is put in place, the criteria for lifting the suspension should be made clear. If the control measures are not effective and the pest becomes established within an area of the FF-PFA, the pest free status of the area, or of the infested area of the FF-PFA, should terminate. Trading partners should be informed of any change in FF-PFA status as soon as possible.
Other circumstances, such as inadequate movement controls or the detection of the target pest upon imported products, may also result in suspension of the FF-PFA.
If bilateral arrangements have been made to cover non-target exotic fruit fly species, the status of the country of FF-PFA will change if the species are detected, until surveillance defines the distribution of the pest.
Reinstatement may take place when:
following identification of non-compliance in implementing agreed procedures and appropriate corrective actions have been implemented to address the non-compliance to the satisfaction of the trading partners.
When a FF-PFA requires complex measures for its establishment and maintenance to provide a high degree of phytosanitary security, an operational plan based on bilateral arrangements may be negotiated and developed between trading partners.
