PRAs for consultation on pest risk management

The species is not known to have caused any economic impact in either its area of origin or where it has established elsewhere.

It is a serious pest of wheat, oats and barley in South Africa. Attacks by the bug in the drier grain-growing area of the Western Cape Province often make cultivation of these crops uneconomic. However, outdoor establishment in the UK is unlikely because the climates of the Western Cape and the UK are very different and this species is unlikely to survive the prolonged cold and damp conditions of British winters except where they are protected, e.g. in farm buildings. This species has not been observed in protected crops. The poor wintering survival, coupled with low population densities if survival did occur, indicates that any impacts are expected to be very small. Where populations have been able to overwinter and establish on grasses and grain crops in the vicinity, densities are likely to be highest in the warmest and driest areas of eastern England but these are still significantly cooler and wetter than areas of South Africa where it is a damaging pest. Control on cereal crops would probably be relatively straightforward, in the absence of insecticide resistance, although it could involve additional treatments and there is some uncertainty concerning the effectiveness of available products. The key issue for this RA is the climatic suitability of the UK in comparison with areas of South Africa where it is a serious pest. Since this has already been explored, a more detailed UK PRA on this pest is not required. Details of this risk assessment should be passed to EPPO for awareness and to alert southern EPPO countries which may be more at risk.

It is likely that M. nitidalis entered the UK in association with tree ferns imported from Australasia. Due to the level of non-native organisms that may be associated with this trade, tree ferns are treated prior to export. Previously, the trade in tree ferns was largely unregulated for 10 years or more and this may have been when this particular pest entered. Some uncertainty exists over the potential economic and environmental impact of the pest on native species. However, there are no records of damage reported in its native habitat. Specialist growers of ferns could also be at a low risk of the moth spreading from tree ferns to other species in a nursery. Overall the environmental and economic impact is expected to be low.

Given that M. nitidalis is already likely to be naturalised, probably having entered on a pathway which has since been regulated, further action and a more detailed PRA are not required.

PRA Summary

• Major hosts:Prunus avium - Sweet/wild cherry; Prunus cerasus - Sour, pie or tart cherry; Prunus salicina - Japanese plum; Pyrus communis - European pear, species from which most orchard cultivars in Europe, USA and Australia are developed
• Minor hosts: Prunus serotina - Wild black cherry, normal wild host in USA; Prunus virginiana - Common choke cherry tree; Prunus mahaleb - Mahaleb cherry
• Incidental: Other Prunus spp

Overall assessment of pest: It is possible for it to enter the UK along the pathways discussed, but unlikely that it would transfer to hosts, find a suitable environment and establish. More information on host and environmental preferences would be required to reduce the level of uncertainty. If it did establish, however, the pest would be difficult to eradicate as it could easily survive in untreated and unmonitored wild host populations. The pest is likely to be detected early in the UK though, due to our lack of other fruit fly pests on cherries with which it may be confused. The area most at risk is the south-east, where conditions are most likely to be favourable and where the largest concentration of hosts (commercial and other) are found.

It is an important economic pest of many tropical and subtropical crops, and citrus, none of which are grown as commercial crops in the UK. It may have a small impact on the aesthetic quality and market value of indoor ornamental plants but there is little data available to quantify the economic implications. In the absence of phytosanitary measures the scale is likely to continue to enter the UK. It may be controlled using the same products used for other soft scales already present in the UK.

The rapid assessment was undertaken to determine if continued statutory action is justified.

With the information that we currently have available on the pest it is not of sufficient concern to the UK to justify a more detailed assessment.

Based on its biology and low potential impact continued action on this pest in the UK would not be considered appropriate. It is likely to be of more concern to southern Member States of the EU, as it is an economic pest of citrus.

Very few of the known host genera are grown outdoors in the UK, being mostly unable to survive harsh winters. They are mainly kept as household ornamental plants and the pest is therefore most likely to find hosts under protection. The optimum conditions for development (23.4°C, 70% humidity), suggests that areas most at risk would be botanical collections with 'tropical glasshouses', their optimum humidity being higher than would normally be found in domestic situations.

The rapid assessment is being carried out to determine whether this pest should be notifiable and if statutory action against it should continue.

With the information that we currently have available on this whitefly it is not of sufficient concern to the UK to justify a more detailed assessment. As such a recommendation for no statutory action is proposed.

There are several closely related species of Parthenolecanium already present in Britain which are controlled by a complex of naturally-occurring parasitic wasps, insect predators and entomopathogenic fungi. P. fletcheri is likely to be controlled, at least partially, by these same natural enemies already present in the UK, so control measures are unlikely to be necessary unless severe infestations occur on individual plants. The population found in Britain was already being controlled to some degree by hymenopteran parasitoids.

Economic impacts are expected to be restricted to a reduction in the aesthetic appearance and therefore market value of ornamental plants although the potential losses are likely to be small.

With the information that we currently have available on the scale it is not of sufficient concern to the UK to justify a more detailed assessment. As such a recommendation for no statutory action is proposed.

If P. peruvianus became established in Britain, the economic impact is likely to be very small, as although it may damage individual bougainvillea plants grown indoors, its host plants are not common in Britain. It is unlikely to have any impact on biodiversity, ecosystems, crops or forestry in the UK. However, there is a degree of uncertainly as it was only described recently (2007) and its full host range, biology and economic importance have not been studied in detail.

With the information that we currently have available on the scale it is not of sufficient concern to the UK to justify a more detailed assessment. As such a recommendation for no statutory action is proposed.

Consultation letter

Lettuce is an important crop in the UK with a 'field-gate' value of £82 million in 2008 (Defra, 2008). It is thought that F. oxysporum f.sp. lactucae is specific to lettuce (Lactuca sativa) and lamb's lettuce (Valerianella locusta) and it is likely that other species are not at risk. The pathogen is known to occur in the EU, having been recorded in Italy in 2001 and Portugal in 2004. It is also present in the USA (the main source of UK seed), parts of Asia and possibly Brazil. As far as is known, this pathogen is not established in field-grown or protected lettuce in the UK. However, there have been no specific surveys for the pathogen. The pathogen has never been regulated, trade in lettuce plants and lettuce seed into and within the EU are not specifically regulated under phytosanitary legislation. This means that the pathogen has not been restricted in its movement and may have already entered the UK. Therefore there may be implications for the prospects of eradication.

1. Immediate move to no statutory action in the event of any future outbreak - i.e. industry management

2. Statutory action against initial outbreaks, but keeping under review and moving to no statutory action if eradication/containment is not achievable.

Further information on the advantages and disadvantages for each option is provided in the attached rapid assessment and summary note.

Consultation letter

EPPO PRA

The attached PRA prepared by an EPPO Expert Working Group in July 2010, concluded that "based on the current knowledge there is a strong probability that SWD could cause significant yield loss and reduction in crop quality". In addition, only the very northern areas of Europe are unsuitable in terms of climate, with all of England and Wales (and most of lowland Scotland) being at risk.

There is no EU regulation of SWD, and this is unlikely to change. The response of other European countries to their findings to date has been focused on trapping surveys to monitor for pest presence, advice on Integrated Pest Management (IPM), information campaigns and destruction of infested host material. Many countries in the EU are now carrying out research into the biology of the pest and the efficacy of different control measures; adapting these measures to develop strategies appropriate to their geographical location and fruit production industries.

• No statutory action, leave to industry to manage
• Work in collaboration to limit spread including limited statutory action when necessary

Further information on the advantages and disadvantages for each option is provided in the attached PRA cover note.

Consultation letter

Consultation paper

Cost benefit analysis

List of consultees

Since 2009 there has only been one recorded outbreak of L. huidobrensis in the UK (in 2011), despite an increase in interceptions from Third countries in recent years. There were also interceptions of Liriomyza sativae and Liriomyza trifolii in 2011.

The main question, therefore, is, whether in the absence of these pests, PZ arrangements should be retained or extended? The PZ would place an emphasis on the supply of clean planting material, serving as a mechanism to shift the focus for controlling and eradicating the pest onto suppliers from outside of the UK reducing the risk of the pest being re-introduced. But it would also involve burdens for industry and Government, to maintain pest free status.

• Maintain the status quo i.e. a Protected Zone for Liriomyza bryoniae in Northern Ireland and existing restrictions on the introduction and movement of L. huidobrensis and L. trifolii
• Maintain the Northern Ireland Protected Zone for Liriomyza bryoniae and expand the requirement to incorporate a UK wide Protected Zone for L. huidobrensis and L. trifolii
• No PZ for any of the Liriomyza spp. on the basis that detections in imports have in general fallen in recent years possibly as a result of improved control measures in other MS and third countries resulting in a reduced risk of the pest being imported and therefore a reduction in the need for a PZ

Furthermore the pest appears to have been present in the UK for a number of years, has already had the opportunity to spread widely and is very likely to be present (undetected) at camellia growers nurseries in the UK. It is very difficult to detect because of its small size and consequently it would be very difficult to prevent spread of this pest. The pest appears relatively straightforward to control, and as it is one of an assemblage of mites and insect pests on camellias, it will probably be controlled by generic control measures for camellia pests. Spray programs appear to have successfully controlled the pest where it has occurred to date in the UK.

In the absence of phytosanitary measures the whitefly is likely to continue to enter the UK. With the information that we currently have available on the whitefly it is not of sufficient concern to the UK to justify a more detailed assessment. No specific management options are available. Destruction of infested plants and precautionary treatment of those remaining may be the simplest and most straightforward way of achieving eradication.

The host plant genus that is of most economic importance in Europe is Citrus, although there do not appear to be published records of A. psidii causing economic damage to citrus.

Unlike other Asian whitefly species that have spread (for example Dialeurodes citri) A. psidii has so far only been recorded in the Andaman and Nicobar Islands and within mainland Asia. This suggests that it may have limited ability to colonise new areas, even when it is carried to areas where hosts are available and the climate is suitable. A. psidii has not demonstrated much capacity to invade new geographical areas.

A. psidii is likely to be restricted to protected ornamental plants and may be controlled by using the same products used against the regulated whitefly pest Bemisia tabaci. With the information that we currently have available on the whitefly it is not of sufficient concern to the UK to justify a more detailed assessment. The EU and EPPO will be notified as it may be more of a concern to southern member states with its hosts including Citrus.

The PRA concluded that there is a high risk of establishment and spread if the pest is introduced into the EPPO region and that if this occurred it would have major economic and environmental consequences. The probability of entry of the pest from the identified pathway was assessed as low to moderate. The PRA concluded that management measures to prevent the introduction, establishment and spread of the pest are appropriate and a number of recommendations were made.

In responding to the consultation we would be particularly keen for views on the proposed management options in the PRA, for example, would they be practical from an industry perspective and about the level of trade, and sources of material.

In the short term:

• A publicity/awareness raising campaign
• Possible national measures (based on the PRA)

Longer term:

• Push for EU wide measures based on the PRA

C. rusci occurs widely in tropical, subtropical and warm temperate areas. It is unlikely to be able to overwinter outdoors in the UK and therefore establishment is likely to be restricted to protected ornamental plants. All previous populations on indoor plantings have been transient.

With the information that we currently have available on the scale it is not of sufficient concern to the UK to justify a more detailed assessment. It is already present in many areas of Europe and the Mediterranean where its most economically important hosts are found. As such a recommendation for no statutory action is proposed.

It is likely to be able to naturalise, at least in southern England, wherever mint is grown. This is what has recently happened with the closely related rosemary beetle, C. americana, which is native to southern Europe, but is now widely naturalised on rosemary across much of the UK.

C. coerulans is not recorded as an economic pest of commercial mint production in Europe, although it is recorded damaging mint in gardens. In some circumstances it is likely to cause serious damage (complete defoliation) to individual cultivated plants in private gardens. On rare occasions, management action may be required in commercial mint crops. Potential yield losses are likely to be small, although it may be more important in organically grown crops. It is unlikely to have any significant impact on biodiversity, ecosystems and forestry in the UK.

In the absence of phytosanitary measures the beetle is likely to continue to enter the UK and measures would be difficult to implement for casual introductions. It is most likely that this beetle will turn up in private gardens, rather than at commercial premises, which could restrict management options.

PepMV PRA cover note

Fera supports the PRA recommendation but also asks respondents for their views on plants for planting. At present statutory action is taken when PepMV is detected in tomato plants for planting but this would not be possible if an Annex IIAII listing was restricted to seeds. Respondents are asked to consider the information at section 3.4.2 of the PRA in considering this issue.

The highest risk areas are restricted to southern England and the economic impact is expected to be small. Natural predators exist for native phylloxerid, which it is expected, would help to control infestations of P. quercus to an acceptable level.

Given that it is not known with any degree of certainty whether or not P. quercus group species are already established in the UK, and that control measures are in any case often unnecessary (as the damage is largely aesthetic) no statutory action is recommended.

Consultation outcome

More rarely nursery stock and gardens.

Although it was thought that the 2009 findings were the first records of the pathogen in the UK, subsequent investigation has revealed that records date back to at least 2004. The pathogen may even have been present at least as far back as early as 1938 but misidentified as another Phytophthora species, many years before P. pseudosyringae was first described (in 2003). P. pseudosyringae is therefore considered to be established here with no prospect of eradication or official control.

PRA cover note