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Following a request from the European Commission, in this scientific opinion the EFSA Panel on Plant Health evaluates the risk of entry into the European Union of harmful organisms associated with soil or growing medium attached to plants for planting, as commodities, and as contaminants on imported consignments. The Panel compared several definitions of soil and growing media and used, in this opinion, the current definition for growing media of the International Plant Protection Convention. In Council Directive 2000/29/EC, no specific definition of soil and growing media is provided but growing media are described in two different ways. From the soil and growing media and/or components thereof identified through extensive literature searches, the Panel distinguished eight groups of soil and growing media and assessed the probability of association of these groups with harmful organisms. A total of 207 scientific publications were reviewed by the Panel in order to identify and rate the effectiveness of options that could reduce the risk of entry of pests posed by the import of soil and growing media. A detailed description and evaluation of the requirements for soil and growing media laid down in current EU legislation on plant health and in a few other regions of the world is provided. The Panel found that the ‘prohibition of import’ is the only phytosanitary measure with a very high effectiveness and a low uncertainty. The effectiveness of the phytosanitary measures ‘pest free production site and preparation of consignment’ is rated as moderate to high with an uncertainty rated as medium to high. Although several phytosanitary measures in these categories of risk reduction options could be highly effective, EU legislation does not provide clear formulation and guidance on their implementation.

The European Commission requested EFSA's Panel on Plant Health to perform the pest categorisation for Clavibacter michiganensis subsp. insidiosus. The identity of the bacterium responsible for the bacterial wilt of lucerne is clearly defined. C. michiganensis subsp. insidiosus is present in only a few MSs in the EU and it is listed in the Annex IIAII of the Directive 2000/29/CE. Only sporadic disease outbreaks occur, and not in countries where lucerne production is of importance. The pathogen causes yield and quality loss only if susceptible cultivars are grown and conditions are favourable for disease expression. The pathogen is not reported in the main lucerne‐producing MSs. There are no indications that in last decade the pathogen has a high impact on lucerne production in the EU, possibly because of the use of bacterial wilt‐resistant varieties. C. michiganensis subsp. insidiosus is seed‐borne and probably seed‐transmitted, although with some uncertainty. The main pathway for long‐distance dispersal of this pathogen is very likely via seeds, while machines and contaminated hay may also potentially play some role in the dissemination of the pathogen. The pathogen can be easily detected and identified on the basis of various microbiological and molecular tests and disease symptoms, including leaf mottling, reduction in plant height, and “witches’ broom” syndrome. Effective management strategies are available and include the use of resistant cultivars and, probably, the use of pathogen‐free seeds. Finally, the Panel concluded that severe consequences, in terms of yield and quality losses, are expected for lucerne only if bacterial wilt‐susceptible varieties are grown and if weather conditions are conducive to the disease.

The Panel on Plant Health performed a pest categorisation of potato stolbur mycoplasma, recently renamed Candidatus Phytoplasma solani (CPs), for the European Union (EU) territory. CPs is a well‐defined species of the genus Candidatus Phytoplasma, for which molecular detection assays are available. It is a regulated harmful organism in the EU, and is listed as potato stolbur mycoplasma in Annex II, Part A, Section II of Council Directive 2000/29/EC. Although CPs can infect a wide range of host plants, this listing concerns only Solanaceae plants for planting. CPs is transmitted by grafting and vegetative propagation of infected hosts, and by several insect vector species including Hyalesthes obsoletus, Reptalus panzeri, Pentastiridius leporinus and possibly others. The geographical distributions and population densities of these vectors govern the spread of CPs. CPs can infect a wide range of host plants and has been reported in 14 EU Member States (MSs). CPs can cause yield losses in potato and other solanaceous crops, in grapevine, strawberry, maize and lavender. Because host plants, wild or cultivated, are widely distributed throughout the EU, the distribution of vector populations is the main determinant of CPs establishment and spread; therefore, CPs has the potential to establish and spread in unaffected parts of the EU with the extension of the distribution range of its vectors. There are high annual fluctuations in the impact of CPs, and this is mostly affected by the prevalence of plant reservoirs for CPs and by the size of local vector populations, which cannot easily be controlled. There are uncertainties regarding the precise distribution of CPs and its vectors, the evolution of vector distribution, the long‐term impact of emerging CPs genotypes and the extent of impact on the various susceptible crops grown in the EU.

The European Commission requested the EFSA Panel on Plant Health to perform the pest categorisation for Erwinia amylovora, which is the causal agent of fire blight. E. amylovora is a plant pathogenic bacterium regulated by the Directive 2000/29/EC (Annexes II‐A‐II). E. amylovora is a single taxonomic entity. This organism can be accurately identified, based on a range of discriminative methods. Detection methods are available for symptomatic and asymptomatic plant material. E. amylovora ispresent in all EU Member States except Estonia, Finland and Malta, where host plants are not widely distributed or are rare. The host plants (mainly pear and apple) are cultivated throughout Europe where environmental conditions are conducive to disease development. Although no recent data are available on losses caused by E. amylovora in the EU, fire blight is considered to be the most destructive disease on pear and apple owing to the loss of trees. The analysis of past disease outbreaks previously reported in the EU highlights their considerable potential to have a severe impact on commercial horticulture, especially on apple, pear and quince, as well as on ornamentals and on nursery trade. The disease causes a range of symptoms on the aerial parts of plants, including the fruits, and E. amylovora often kills the trees and causes destructive outbreaks. Contaminated rootstocks, cuttings and grafted trees for transplanting, beehive transportation, rain and wind, are responsible for medium‐ and long‐distance dissemination of the pathogen. Existing control is mainly based on prevention and exclusion. The use of chemical or biological products can prevent infection, and sanitation methods applied to infected plants can control the disease to a certain extent. No curative chemical control agents are available that eradicate E. amylovora in infected orchards.

The European Commission requested the EFSA Panel on Plant Health to perform a pest categorisation of Verticillium albo‐atrum Reinke and Berthold, the causal agent of Verticillium wilts. V. albo‐atrum causes wilt and plant death, impairing the growth and shortening the lifespan of its hosts. V. albo‐atrum was recently split into three species, V. albo‐atrum sensu stricto V. alfalfae and V. nonalfalfae for which reliable detection and identification methods exist. V. albo‐atrum sensu lato is present in most parts of the EU. The new taxonomic status of the pathogen, and the confusion that existed in the past between V. albo‐atrum sensu lato and V. dahliae, cause uncertainty on its distribution worldwide and in the EU. Based on recent studies, the presence of each of the new species (V. albo‐atrum sensu stricto, V. alfalfae V. nonalfalfae) has so far been confirmed in a relatively small part of the EU. The pathogen has a wide host range. In the EU, it affects many cultivated and non‐cultivated plant species, including some very important crops (alfalfa, cotton, hop, potato and tomato). However, the so far known host range of each of the above‐mentioned new species is more restricted than that of V. albo‐atrum sensu lato. There are no obvious ecoclimatic factors limiting the potential establishment and spread of the pathogen in the non‐infested part of the EU where hosts are present. Once established, the pathogen can spread by natural and human‐assisted means. Movement of infected host plants for planting, especially asymptomatic plants, can introduce the pathogen into new areas. Integrated management strategies may reduce impacts of V. albo‐atrum sensu lato in the EU, but they do not eliminate the pathogen. V. albo‐atrum sensu lato is listed in Annex IIAII of Directive 2000/29/EC. Despite its wide host range, it is regulated only on Humulus lupulus.

The European Commission requested EFSA's Panel on Plant Health to perform the pest categorisation for Xylophilus ampelinus, which is the causal agent of bacterial necrosis of grapevine. X. ampelinus is a single taxonomic entity and grapevine is the only known host. X. ampelinus is regulated in the EU; it is listed in Annex II, Part A, Section II of the Directive 2000/29/EC. Reliable detection and identification tests are available. X. ampelinus is present on grapevine in 5 out of the 21 grapevine‐producing EU countries. Nevertheless, it should be stressed that disease occurrence is sporadic in areas where X. ampelinus is present and depends on cultivar susceptibility and environmental conditions. The survival of X. ampelinus is unlikely to be affected by ecoclimatic conditions. In areas where X. ampelinus is present, the direct and indirect impacts can be high: yield reduction, death of grapevine plants and specific disease management procedures (use of healthy plant for planting, cumbersome management of infected vineyards). X. ampelinus is transmitted locally by rain, wind, overhead sprinkler irrigation and human activity within vineyards, and by plants for planting material over long distances, especially as infected planting material is, most of the time, asymptomatic. Control measures include the destruction of the infected plants and the application of copper compounds.

The Panel on Plant Health undertook a pest categorisation for the scale insect Aonidiella citrina for the European Union. A. citrina is a distinct species, but examination with a microscope is required to distinguish it from A. aurantii, which is also a citrus pest originating from Asia, but is much more widespread in southern Europe and far more damaging than A. citrina. A. citrina was first found in Europe in 1994 but has been recorded only in Italy, France and Greece. It is primarily a citrus pest, but has been found in association with a variety of other plant genera. Southern areas of the EU, where citrus plants are cultivated, are potentially suitable for outdoor establishment of A. citrina. The pest has not been recorded in protected cultivation. No serious impacts of A. citrina have been recorded in Europe, and an integrated pest management programme, combining chemical and biological controls, is considered to be effective. A. citrina is an insect listed in Annex IIAI of Council Directive 2000/29/EC in relation to its main hosts: Citrus, Fortunella and Poncirus plants. These hosts are also regulated in Annex III and Annex V and are explicitly mentioned in Council Directive 2008/90/EC.

The European Commission requested the EFSA Panel on Plant Health to perform the pest categorisation for Xanthomonas campestris pv. vesicatoria, which is the causal agent of bacterial spot of tomato and pepper. X. campestris pv. vesicatoria is not a single taxonomic entity, and four separate species have been described: X. vesicatoria, X. euvesicatoria, X. perforans and X. gardneri. These organisms can be accurately identified based on a range of discriminative methods. Detection methods are available for seeds. Among the four species described within X. campestris pv. vesicatoria, all except X. gardneri were reported to be present in the EU territory. The host plants (tomato and pepper) are cultivated throughout Europe and conditions are conducive to disease development in open fields in southern Europe and in greenhouses. The disease causes a range of symptoms on aerial parts of plants including fruits. Contaminated seeds and transplants are responsible for longdistance dissemination of the pathogen. Control is mainly based on prevention and exclusion. Extraction of seeds from fruit debris using fermentation and acid treatments and thermotherapy treatments were shown to be effective in reducing the bacterial load in seed lots. No methods and chemical control agents are available that effectively control xanthomonads in infected crops. Although no recent data are available on economic losses caused by these pathogens in the EU, the organisms are considered important bacterial pathogens of tomato and pepper. Infections resulting in up to 30 % losses have been reported. Xanthomonads causing bacterial spot of tomato and pepper meet all criteria defined in International Standard for Phytosanitary Measures (ISPM) 21 and they also meet all ISPM 11 criteria, although X. vesicatoria, X. euvesicatoria and X. perforans are present in the EU territory. © European Food Safety Authority, 2014

The European Commission requested the EFSA Panel on Plant Health to perform the pest categorisation for Clavibacter michiganensis subsp. michiganensis (Cmm). The agent responsible for vascular tomato wilt and canker is the clearly defined and valid gram-positive taxon C. michiganensis subsp. michiganensis. This pathogen can be accurately identified based on a range of sensitive and specific methods. Tomato (Solanum lycopersicum) is the main host, but peppers (Capsicum annum and C. frutescens) are also naturally susceptible to Cmm. These host plants are cultivated throughout Europe and conditions are conducive to disease development in open fields in southern Europe and in greenhouses. The disease is present in many EU Member States. Outbreaks are rare but usually severe. It causes a range of symptoms on the aerial parts of plants, including the fruits. Detection methods are available for any type of plant material either presenting symptoms or symptomless. Seed testing has proven to be a good control option by discarding contaminated seed lots. Despite tomato seed production being done under strict sanitation using recommended practices, seed contamination still occurs occasionally. Contaminated seeds and transplants are responsible for long-distance dissemination of the pathogen. Under conducive conditions, even low levels of seed contamination can result in disease outbreaks. Cultivation practices can favour secondary spread of the bacterium and an increase in disease incidence both in greenhouse and in open-field crops. No effective biological or chemical control agents are registered for bacterial canker in Europe. Cmm meets all criteria defined in International Standard for Phytosanitary Measures (ISPM) 21. Cmm meets all ISPM 11 criteria, although it has been observed in 16 EU Member States. The outbreaks are usually severe but sporadic.

The Panel on Plant Health assessed the risk to plant health of Strawberry crinkle virus (SCV) for the European Union (EU) territory, and evaluated the current EU legislation and possible risk reduction options. This virus is widely distributed both within and outside Europe and the same applies to its main vector, the strawberry aphid, Chaetosiphon fragaefolii. At-risk hosts (Fragaria spp.) occur widely in Europe. Plants for planting were identified as the most significant entry pathway and the probability of entry is rated as unlikely to moderately likely with high uncertainty. The probability of establishment is rated as very likely with low uncertainty. The probability of local spread by natural means is moderately likely, with high uncertainty, whereas that of human-assisted long-distance spread is unlikely, with medium uncertainty. The potential consequences are rated as minimal to minor with medium uncertainty. Prohibition and restricting import or intra-EU trade to certified materials or to materials originating from pest-free areas or pest-free places of production are the options with highest effectiveness against the risks of introduction or against the risks of further spread. Prohibition and certification are also among the options of high or very high feasibility. In addition, it should be noted that the combination of options (cultural practices, certification, exclusion conditions, tolerant varieties) has an overall high to very high level of effectiveness and feasibility. The current legislation has few weaknesses: the reliance on visual inspection, as well as the exceptions or derogations offered to some countries in which SCV is present. If the current legislation were removed, no major consequences would be expected unless the industry simultaneously ceased its widely adopted certification activity, which seems unlikely given the potential consequences.

EFSA requested the PLH Panel to review the current state of the art of the biology and ecology of apple snails, reported in this opinion, and to perform an environmental risk assessment for validation of the Plant Health environment guidance document, which will be provided in a second opinion. The Panel presents in this opinion the current state of the art of the biology of apple snails, and develops and uses a population dynamics model to assess the potential establishment of apple snails in the EU. A thorough review of the literature on the biology of Pomacea canaliculata and P. maculata was performed to collect information and data on life history characteristics related to temperature, which was used in the population dynamics model. Although uncertainties on the systematics and taxonomy of the genus Pomacea remain, it is now acknowledged that Pomacea insularum is a synonym of P. maculata and can be undoubtedly differentiated from P. canaliculata. Natural spread occurs via rivers and canals, in which the snails crawl, drift, float and raft. Flooding increases spread. In addition, attachment to animals (e.g. birds, cattle, horses, deer and aquatic invertebrates) results in spread. Human assistance results in spread through cultivation transport of rice seedlings, aquaculture, aquaria, boats, and agricultural field machinery. The potential distribution of P. canaliculata in Europe was obtained by calculating with the population dynamics model, the average snail abundance per year in each node of a grid of 0.25 × 0.25 degrees covering Europe, which resulted in the following conclusions: (1) the area of potential establishment comprises wetlands of southern Europe (i.e. Spain, southern France, most of Italy and Greece) and the Balkans up to the latitude of the Danube river, (2) the potential area of establishment includes the rice production areas in Europe. © European Food Safety Authority, 2013