Pest categorisation of Unaspis citri

The Panel on Plant Health performed a pest categorisation of the citrus snow scale, Unaspis citri (Comstock) (Hemiptera: Diaspididae), for the European Union (EU). This is a well-de fi ned and distinguishable species, native to south-eastern Asia, which has spread to many tropical and subtropical regions. U. citri can be a pest of citrus and has been cited on over 28 different species in 16 plant families. In the EU, U. citri occurs in the Azores. There is uncertainty as to whether it occurs in continental Portugal. Reports of it occurring in Greece and Spain are likely to be invalid and based on interception records from these countries. An old Italian record is a misidenti fi cation. U. citri is listed in Annex IIAI of 2000/29/EC as a harmful organism. The international trade of hosts, as either plants for planting, fruit or cut fl owers, provide potential pathways into the EU. However, current EU legislation prohibits the import of citrus plants for planting from third countries. U. citri is mostly con fi ned to coastal humid tropical areas and does not occur in semi-arid areas that are irrigated. Nevertheless, given that it occurs in the Azores and that there are regional climatic similarities between places where U. citri occurs and climates within the EU, and taking EU host distribution into account, U. citri has the potential to establish in the EU, especially in citrus-growing regions around the Mediterranean where losses in quality and yield of citrus could occur. Phytosanitary measures are available to inhibit the likelihood of introduction of U. citri . Considering the criteria within the remit of EFSA to assess the status as a potential Union quarantine pest (QP), or as a potential regulated non-quarantine pest (RNQP), U. citri meets the criteria assessed by EFSA for consideration as a potential Union QP

Hot water treatment of Vitis sp. for Xylella fastidiosa

Following a request from the European Commission, the EFSA Panel on Plant Health (PLH) reviewed Italian technical guidelines and the ANSES (Agence nationale de sécurité sanitaire de l’alimentation, de l’environnement et du travail) opinion on the use of hot water treatment (HWT) on Vitis sp. planting material, assessing its efficacy in the elimination of the xylem-invading bacterial pathogen, Xylella fastidiosa. HWT is a robust and reliable technique used to destroy life stages of pests (insects, nematodes) and to inactivate pathogens (phytoplasma, bacteria, fungi) in dormant plant propagation materials (grapevine and other crops). An effective HWT sanitizes the planting material without affecting plant survival and development. For grapevine, HWT to eliminate the Grapevine flavescence dorée phytoplasma (FD) from planting materials is among the special requirements for the introduction and movement of Vitis sp. to protected zones in the EU. The conditions of 50°C for 45 min, prescribed and recommended to sanitize grapevine planting material against FD, are considered by the Panel to be also effective against X. fastidiosa and its subspecies. Despite uncertainties on variable thermotolerances of the bacteria, a HWT treatment of 50°C for 45 minutes can effectively account for different thermotolerances. It should be noted that the quality of the HWT is subject to the proper application of the operating procedures to guarantee vigorous growth and pathogen freedom of planting material

Pest categorisation of Scirtothrips citri

The Panel on Plant Health performed a pest categorisation of the citrus thrips, Scirtothrips citri (Moulton) (Thysanoptera: Thripidae), for the European Union (EU). This is a well-de fi ned and distinguishable species, occurring in North America and Asia. Its precise distribution in Asia is uncertain. S. citri is a pest of citrus and blueberries and has been cited on over 50 different host species in 33 plant families. Whether all plants reported as hosts are true hosts, allowing population development of S. citri , is uncertain. S. citri feeds exclusively on young actively growing foliage and fruit. It is not known to occur in the EU and is listed in Annex IIAI of 2000/29/EC as a harmful organism. The international trade of hosts, as either plants for planting or cut fl owers, provide potential pathways into the EU. However, current EU legislation prohibits the import of citrus plants for planting. Furthermore, measures aimed at the import of plants for planting in a dormant stage (no young foliage or fruits present) with no soil/growing medium attached, decreases the likelihood of the pest ’ s entry via other hosts. Considering that there are regional climatic similarities where S. citri occurs in the USA with climates in the EU, and taking EU host distribution into account, S. citri has the potential to establish in the EU, especially in citrus and blueberry growing regions around the Mediterranean where quality losses in citrus and yield losses in blueberry could occur. Phytosanitary measures are available to inhibit the likelihood of introduction of S. citri from infested countries. Considering the criteria within the remit of EFSA to assess its status as a potential Union quarantine pest (QP) or as a potential regulated non-quarantine pest (RNQP), S. citri meets with no uncertainties the criteria assessed by EFSA for consideration as a potential Union QP

Pest categorisation of Toxoptera citricida

23The European Commission requested EFSA to conduct a pest categorisation of Toxoptera citricida (Hemiptera: Aphididae), an oligophagous aphid developing and reproducing parthenogenetically on tender leaf and flower flush of citrus (Rutaceae). T.citricida is a taxonomic entity with reliable methods available for detection and identification. It is regulated in the EU by Council Directive 2000/29/EC where it is listed in Annex IIAI as a harmful organism whose introduction and spread into the EU shall be banned. T.citricida is native to tropical regions of Southeast Asia and has spread to most citrus-growing areas worldwide, except California and the Mediterranean basin, causing significant damage to citrus as it is the most efficient vector of the Citrus tristeza virus (CTV). T.citricida occurs in Madeira and, with a restricted distribution, in the north-west of the Iberian Peninsula, mostly on backyard citrus trees. This may have hindered the effectiveness of the official control measures in these areas. There are further phytosanitary measures in place in the EU in order to limit entry via traded commodities. Citrus plants for planting are regulated and are a closed pathway. However, there is uncertainty regarding host status of some non-rutaceous plants on which this aphid has been recorded and so other plant genera may provide additional pathways. The EFSA Plant Health Panelconcludes that the establishment of T.citricida in the main EU citrus growing areas around the Mediterranean would have significant impacts because of its ability to vector CTV. Considering the criteria within the remit of EFSA to assess the status as a potential Union quarantine pest (QP), as a potential protected zone quarantine pest (PZQP) or as a potential regulated non-quarantine pest (RNQP), T.citricida meets with no uncertainties the criteria assessed by EFSA for consideration as a potential Union QP.openopenJeger, Michael; Bragard, Claude; Caffier, David; Candresse, Thierry; Chatzivassiliou, Elisavet; Dehnen‐Schmutz, Katharina; Gilioli, Gianni; Grégoire, Jean‐Claude; Jaques Miret, Josep Anton; Navarro, Maria Navajas; Niere, Björn; Parnell, Stephen; Potting, Roel; Rafoss, Trond; Rossi, Vittorio; Urek, Gregor; Van Bruggen, Ariena; Van der Werf, Wopke; West, Jonathan; Winter, Stephan; Gardi, Ciro; Bergeretti, Filippo; MacLeod, AlanJeger, Michael; Bragard, Claude; Caffier, David; Candresse, Thierry; Chatzivassiliou, Elisavet; Dehnen‐schmutz, Katharina; Gilioli, Gianni; Grégoire, Jean‐claude; Jaques Miret, Josep Anton; Navarro, Maria Navajas; Niere, Björn; Parnell, Stephen; Potting, Roel; Rafoss, Trond; Rossi, Vittorio; Urek, Gregor; Van Bruggen, Ariena; Van der Werf, Wopke; West, Jonathan; Winter, Stephan; Gardi, Ciro; Bergeretti, Filippo; Macleod, Ala

Vitis sp. response to Xylella fastidiosa strain CoDiRO

Following a request from the European Commission, the EFSA Panel on Plant Health assessed a scientific report submitted by the Italian Authorities to the European Commission to support a request to delist Vitissp. from Annex I (‘specified plants’) of the Commission Implementing Decision (EU) 2015/789 of 18 May 2015 to prevent the introduction into and the spread within the Union of Xylella fastidiosa (Wells et al.). The report comprised (i) surveys to detect X. fastidiosa in vineyards located in the epidemic zone of CoDiRO with high numbers of diseased olive trees; (ii) inoculation experiments to infect grapevine with a X. fastidiosa isolate ‘De Donno’ from CoDiRO diseased olives; and (iii) vector transmission experiments with X. fastidiosa infective Philaenus spumarius. The Panel acknowledges the difficulties in providing evidence about this hitherto unknown pathogen/vector/host interaction to support the hypothesis that a plant species cannot be infected with a pathogen. Although field surveys to detect X. fastidiosa in grapevine were negative, there was no supporting information on infective vector populations present in the vineyards. Hence absence of infection pressure cannot be excluded. Furthermore the failure to infect grapevine plants either by artificial inoculation or by vector transmission might be due to inoculation conditions not appropriate to induce infections in grapevine. The detection of X. fastidiosa DNA in inoculated grapevine plants even 12 months after inoculation, although localised at the inoculation points, cannot exclude that the DNA amplified by qPCR was from viable cells. The results presented are coherent and provide converging lines of evidence that grapevine (Vitis vinifera) is not a major susceptible host of X. fastidiosa strain CoDiRO. However, from the experimental evidence it is premature to exclude that systemic infections of V.vinifera and Vitissp. occur and that infections at limited foci could serve as a source of inoculum

Pest categorisation of Venturia nashicola

The Panelon Plant Health performed a pest categorisation of Venturianashicola, the causal agent of Asian pear scab, for the European Union (EU). The pathogen is a well-defined, distinguishable fungal species affecting Pyruspyrifolia var. culta, P.ussuriensis and P.bretschneideri in Asian countries. P.communis (European pear) is not a host of V.nashicola, but the host status of other Pyrus species is unclear. V.nashicola is not known to occur in the EU. It is listed in Annex IIAI of Directive 2000/29/EC. The pathogen could potentially enter the EU on host plants for planting and fruit originated in infested countries. There are no climatic factors limiting the potential establishment and spread of the pathogen in the EU, as its epidemiology is similar to those of Venturiainaequalis (apple scab) and Venturiapyrina (European pear scab), which are well-established in the EU. The hosts are present in the EU, but no data were found on their abundance and distribution. In the infested areas, V.nashicola causes premature leaf and fruit drop and fruit distortion resulting in considerable yield/quality losses. The introduction of the pathogen into the EU could cause yield/quality losses and environmental consequences because of the additional fungicide sprays for disease control. Cultural practices and chemical measures applied in the infested areas reduce the inoculum sources but they cannot eliminate the pathogen. Phytosanitary measures are available to mitigate the risk of introduction and spread of the pathogen in the EU. All criteria assessed by EFSA for consideration as a potential Union quarantine pest are met. As V.nashicola is not known to occur in the EU, this criterion assessed by EFSA to consider it as a Union regulated non-quarantine pest is not met