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. 2023 Jul 28;21(7):e08118. doi: 10.2903/j.efsa.2023.8118
Overview of the evaluation of Thaumetopoea processionea for bundles of whips and seedlings
Rating of the likelihood of pest freedom Almost always pest free (based on the Median).
Percentile of the distribution 5% 25% Median 75% 95%
Proportion of pest‐free bundles 9,992 out of 10,000 bundles 9,995 out of 10,000 bundles 9,997 out of 10,000 bundles 9,998.5 out of 10,000 bundles 9,999.6 out of 10,000 bundles
Percentile of the distribution 5% 25% Median 75% 95%
Proportion of infested bundles 0.4 out of 10,000 bundles 1.5 out of 10,000 bundles 3 out of 10,000 bundles 5 out of 10,000 bundles 8 out of 10,000 bundles
Summary of the information used for the evaluation

Possibility that the pest could become associated with the commodity

The pest is present in the UK territory because of an introduction from the EU with infested plants in early 2000. The species is established in the Greater London area and a buffer zone is delimited each year around the infestation points that are going through eradication. Several eradications of newly found spots were carried out successfully in the whole country while eradication is not considered any longer possible in the establishment area. One of the production nurseries is included in the 2022 buffer zone. In the documents provided by the applicant there is no mention of Fagus as host of the pest. Fagus has been found to host the pest only occasionally in the Netherlands, because of spill over from heavily infested oak trees. The pest, however, can develop from mature larva to moth on Fagus. Egg masses and young larvae were never found on Fagus either in the EU or in the UK.

Measures taken against the pest and their efficacy

Nursery staff is trained to identify the development stages of the pest and regular inspections are carried out in the nurseries. The pest was never detected so no specific measures were adopted.

Interception records

The pest was intercepted frequently on plants for planting of Quercus from the EU to the UK, never on Fagus.

Shortcomings of current measures/procedures

Although the nursery staff is trained, the frequent interceptions of the pest on nursery material indicates that the pest is very difficult to detect, especially at the egg stage because the egg masses have the same colour of the twigs on which they are laid. The detection of the pest at the egg stage is difficult on large plants because of the high number of twigs to check, and especially when they are carrying leaves.

Main uncertainties
  • The possibility for the moth to lay egg masses on Fagus.
  • The possibility for the young larvae to feed on Fagus leaves.
Overview of the evaluation of Thaumetopoea processionea for bare root plants/trees up to 7 years old
Rating of the likelihood of pest freedom Almost always pest free (based on the Median).
Percentile of the distribution 5% 25% Median 75% 95%
Proportion of pest‐free plants 9,992 out of 10,000 plants 9,995 out of 10,000 plants 9,997 out of 10,000 plants 9,998.5 out of 10,000 plants 9,999.6 out of 10,000 plants
Percentile of the distribution 5% 25% Median 75% 95%
Proportion of infested plants 0.4 out of 10,000 plants 1.5 out of 10,000 plants 3 out of 10,000 plants 5 out of 10,000 plants 8 out of 10,000 plants
Summary of the information used for the evaluation

Possibility that the pest could become associated with the commodity

The pest is present in the UK territory because of an introduction from the EU with infested plants in early 2000. The species is established in the Greater London area and a buffer zone is delimited each year around the infestation points that are going through eradication. Several eradications of newly found spots were carried out successfully in the whole country while eradication is not considered any longer possible in the establishment area. One of the production nurseries is included in the 2022 buffer zone. In the documents provided by the applicant there is no mention of Fagus as host of the pest. Fagus has been found to host the pest only occasionally in the Netherlands, because of spill over from heavily infested oak trees. The pest, however, can develop from mature larva to moth on Fagus. Egg masses and young larvae were never found on Fagus either in the EU or in the UK.

Measures taken against the pest and their efficacy

Nursery staff is trained to identify the development stages of the pest and regular inspections are carried out in the nurseries. The pest was never detected so no specific measures were adopted.

Interception records

The pest was intercepted frequently on plants for planting of Quercus from the EU to the UK, never on Fagus.

Shortcomings of current measures/procedures

Although the nursery staff is trained, the frequent interceptions of the pest on nursery material indicates that the pest is very difficult to detect, especially at the egg stage because the egg masses have the same colour of the twigs on which they are laid. The detection of the pest at the egg stage is difficult on large plants because of the high number of twigs to check, and especially when they are carrying leaves.

Main uncertainties
  • The possibility for the moth to lay egg masses on Fagus.
  • The possibility for the young larvae to feed on Fagus leaves.
Overview of the evaluation of Thaumetopoea processionea for plants in pots up to 15 years old
Rating of the likelihood of pest freedom Pest free with few exceptional cases (based on the Median).
Percentile of the distribution 5% 25% Median 75% 95%
Proportion of pest‐free plants 9,971 out of 10,000 plants 9,984 out of 10,000 plants 9,992 out of 10,000 plants 9,996 out of 10,000 plants 9,999.2 out of 10,000 plants
Percentile of the distribution 5% 25% Median 75% 95%
Proportion of infested plants 0.8 out of 10,000 plants 4 out of 10,000 plants 8 out of 10,000 plants 16 out of 10,000 plants 29 out of 10,000 plants
Summary of the information used for the evaluation

Possibility that the pest could become associated with the commodity

The pest is present in the UK territory because of an introduction from the EU with infested plants in early 2000. The species is established in the Greater London area and a buffer zone is delimited each year around the infestation points that are going through eradication. Several eradications of newly found spots were carried out successfully in the whole country while eradication is not considered any longer possible in the establishment area. One of the production nurseries is included in the 2022 buffer zone. In the documents provided by the applicant there is no mention of Fagus as host of the pest. Fagus has been found to host the pest only occasionally in the Netherlands, because of spill over from heavily infested oak trees. The pest, however, can develop from mature larva to moth on Fagus. Egg masses and young larvae were never found on Fagus either in the EU or in the UK.

Measures taken against the pest and their efficacy

Nursery staff is trained to identify the development stages of the pest and regular inspections are carried out in the nurseries. The pest was never detected so no specific measures were adopted.

Interception records

The pest was intercepted frequently on plants for planting of Quercus from the EU to the UK, never on Fagus.

Shortcomings of current measures/procedures

Although the nursery staff is trained, the frequent interceptions of the pest on nursery material indicates that the pest is very difficult to detect, especially at the egg stage because the egg masses have the same colour of the twigs on which they are laid. The detection of the pest at the egg stage is difficult on large plants because of the high number of twigs to check, and especially when they are carrying leaves.

Main uncertainties
  • The possibility for the moth to lay egg masses on Fagus.
  • The possibility for the young larvae to feed on Fagus leaves.
  • Whether and to which extent plants transplanted to the pots before export have undergone a cleaning of roots.