Suchergebnisse

The EFSA Panel on Plant Health undertook a pest categorisation of the insect Scirtothrips dorsalis for the European Union. Although there are reports that this is a species complex and there are host-specific races, it is generally treated as a distinct taxon. Both morphological and molecular methods are required to confirm identification. Apart from one long-term outbreak in a botanic garden glasshouse in England, it is absent from the EU. Native to southern and eastern Asia, this species has been introduced to tropical and subtropical areas of Africa, Australasia and the Americas in recent years. It is highly polyphagous, with over 225 known hosts, which include many important EU crops. Southern areas of the EU are potentially suitable for outdoor establishment and it could establish in protected cultivation throughout the EU. Based on its phenology, the Panel showed that the climate in southern Europe could allow a similar number of generations to develop as in Japan and South Korea, where significant damage occurs to citrus and other crops outdoors. In protected cultivation, even though control methods used against other thrips species may be effective in keeping populations at low densities, damage can still occur at these densities owing to the transmission of tospoviruses. Despite being highly polyphagous, S. dorsalis is an insect listed in Annex IIAI of Council Directive 2000/29/EC only in relation to Citrus, Fortunella and Poncirus plants. These hosts are also regulated in Annex III and Annex V. They are also explicitly mentioned in Council Directive 2008/90/EC.

The Panel on Plant Health performed a pest categorisation of European isolates of Citrus tristeza virus (CTV) for the European Union (EU) territory. European CTV isolates are listed in Annexes IIAII and IIB of Directive 2000/29/EC. CTV is a well-defined and easily diagnosed Closterovirus species transmitted by the vegetative multiplication of infected hosts and through the activity of aphid vectors. Toxoptera citricida is the most efficient vector but Aphis gossypii is the most important in Europe. European isolates of CTV have been reported in seven of the eight EU Member States (MSs) with significant citrus production. The natural host range of CTV is restricted to citrus species and to a few, related genera, such as Fortunella and Poncirus. CTV is unlikely to be affected by ecoclimatic conditions in regions where its host plants are grown and has the potential to establish in southern regions of the EU territory. The majority of European CTV isolates cause severe decline symptoms (tristeza disease) in several citrus species, in particular sweet orange and mandarin grafted on susceptible sour orange or lemon rootstocks, which are commonly used in many EU MSs with the exception of Spain and, to a lesser extent, France. Symptoms of the severe stem pitting disease (SP) have not been reported by any EU MSs, despite the identification of isolates closely related to non-European isolates that cause SP in other regions of the world. The observed impact of CTV is on citrus industries still heavily reliant on susceptible rootstocks. Replacing those with CTV-tolerant rootstocks, as was done in Spain, virtually eliminates the impact of CTV in the absence of SP. Comprehensive certification systems can also reduce CTV spread and impact. The most critical area of uncertainty concerns the potential ability of some European isolates to cause SP in sweet orange.

The EFSA Panel on Plant Health undertook a pest categorisation of the insect Rhagoletis ribicola for the European Union. This taxonomically distinct species is known to occur only in western states of the USA and Canada, where it feeds on Ribes aureum, R. rubrum and R. uva-crispa. There have been no records of it causing serious damage for over 70 years. Its geographical distribution implies that all parts of the risk assessment area where its hosts occur, i.e. all but lowland southern areas of the EU, would be suitable for establishment. Adults of the Rhagoletis genus have a limited capacity for flight. Furthermore, there are no records of R. ribicola moving via international trade routes. Therefore, spread would be most likely to occur as a result of larvae in fruit or pupae in soil. Should the pest be introduced to the EU, the limited control measures available would be similar to those used for other Rhagoletis species, being primarily based on insecticide sprays, timed to kill adults, combined with cultural methods, e.g. netting and trapping. As a non-European tephritid, R. ribicola is listed in Annex IAI of Council Directive 2000/29/EC, and requirements for Ribes are set out in Annex V of Council Directive 2000/29/EC. In addition, Ribes spp. plant material should be produced in accordance with the requirements laid down in Council Directive 2008/90/EC on the marketing of fruit plants propagating material and fruit plants intended for fruit production.

The Panel on Plant Health performed a pest categorisation of Prunus necrotic ringspot virus (PNRSV) for the European Union (EU) territory. PNRSV is a well-defined virus species of the genus Ilarvirus for which the entire genome sequence and molecular detection assays are available. It is transmitted by vegetative multiplication of infected hosts and also via seeds and pollen (both horizontally and vertically) in some of its hosts. PNRSV has a somewhat restricted natural host range, which contains Prunus spp., hops, roses and Rubus ellipticus (yellow Himalayan raspberry). It is listed on plants of Rubus for planting in Annex IIAI of Directive 2000/29EC, probably as a result of confusion with the closely related Apple mosaic virus. PNRSV is widely present in the EU, but there are no records on its regulated hosts. It is not expected to be affected by ecoclimatic conditions wherever its hosts are present, and it has the potential to establish in large parts of the EU territory. PNRSV can spread through efficient seed- and pollen-mediated transmission mechanisms and through the movement of vegetatively propagated plants for planting. However, the existence of efficient and widely adopted certification systems for Prunus spp. constitutes a limitation to PNRSV spread. Although the virus alone or when in mixed infection can cause significant diseases in some hosts, the actual impact of PNRSV appears to be limited.

The European Commission requested that the EFSA Panel on Plant Health perform a pest categorisation for Radopholus similis and Radopholus citrophilus. R. similis is regulated in Annex II, Part A, Section II of Council Directive 2000/29/EC as a harmful organism known to occur in the European Union (EU). R. citrophilus is regulated in Annex II, Part A, Section I of Council Directive 2000/29/EC as a harmful organism not known to occur in the EU. This pest characterisation applies only to R. similis, because R. citrophilus has been recognised as an invalid species designation and is considered as a junior synonym of R. similis. R. similis is a distinct taxonomic entity that is absent in the field production sites (citrus, bananas) of the risk assessment area and can cause significant losses in citrus production. Moreover, various susceptible hosts other than citrus species are present in the EU under climatic conditions that are suitable for the development of R. similis. The pest has a sporadic presence on ornamental plants (under protected cultivation) in a few EU countries. Plants for planting are a pathway for introduction and spread of R. similis. The pest is observed to cause impacts on ornamentals in some MSs and further impacts are expected should further spread happen in the EU.

The Panel on Plant Health performed for the European Union (EU) territory a pest categorisation of Tomato yellow leaf curl virus (TYLCV) and three related viruses, Tomato yellow leaf curl Sardinia virus (TYLCSV), Tomato yellow leaf curl Axarquia virus (TYLCAxV) and Tomato yellow leaf curl Malaga virus (TYLCMaV), which collectively cause the tomato yellow leaf curl disease (TYLCD) in Europe. The viruses are well-defined species of the genus Begomovirus, are exclusively transmitted by members of the Bemisia tabaci species complex and have tomato, as well as a few other crops or weeds, as their hosts. TYLCV is listed on tomato plants for planting, other than seeds, in Annex IIAII of Directive 2000/29/EC. While establishment and local spread rely on the Bemisia vector, the viruses can also be disseminated over long distances by movement of infected plants for planting or by consignments of non-host plants carrying viruliferous whiteflies. Establishment outdoors and spread are limited to regions with ecoclimatic conditions suitable for the establishment of vector populations in the open. Outbreaks can nevertheless occur in other regions under protected cultivation conditions. Because of the very high potential impact of TYLCD, tomato production in affected regions requires intensive crop management efforts to reduce impact. TYLCV appears to be present in almost all EU regions with suitable ecoclimatic conditions for its establishment in open fields, while the other three viruses do not appear to have reached their full establishment potential. All four viruses are absent from other regions of the EU but have the potential to cause temporary outbreaks there.

The EFSA Panel on Plant Health performed a pest categorisation of Cadang-Cadang viroid for the European Union (EU) territory. Coconut cadang-cadang viroid (CCCVd) is a well-known viroid for which efficient molecular detection assays are available. It is transmitted by vegetative multiplication of infected hosts, by seed and pollen and, possibly, by the action of unknown vector(s). CCCVd is reported from a few countries in Asia and is not known to occur in the EU. It therefore does not meet one of the criteria for being a Union regulated non-quarantine pest. The host range of CCCVd is restricted to Arecaceae species (palms), in particular coconut and it is listed on all known hosts in Annex IIAI of Directive 2000/29/EC. CCCVd is expected to be able to enter in the EU and to be able to establish in the open in the southernmost regions of the EU and elsewhere under protected cultivation. It has the potential to subsequently spread via plants for planting and possibly other mechanisms. CCCVd is able to cause severe symptoms in some Arecaceae species while others seem less affected. The potential impact of CCCVd if introduced in the EU is very difficult to assess. Given that the spread potential is, as for other viroids, likely to be limited, the potential impact is estimated to be limited in extent but this judgement is affected by large uncertainties. Overall, CCCVd meets all the criteria evaluated by EFSA to qualify as Union quarantine pest. The main knowledge gaps concern (1) the relationships between CCCVd-related RNAs and CCCVd, (2) the origin and volume of the trade in palm seeds and plants for planting imported in the EU (3) the efficiency of natural spread under EU conditions and (4) host status and susceptibility of many palm species grown in the EU.