The Panel on Plant Health performed a pest categorisation of nematodes belonging to the genus Hirschmanniella (Nematoda: Pratylenchidae). Twenty‐nine species in this genus have been considered of ...which five species are present in the EU (Hirschmanniella behningi, Hirschmanniella gracilis, Hirschmanniella halophila, Hirschmanniella loofi and Hirschmanniella zostericola). The whole genus except H. gracilis is regulated by Council Directive 2000/29/EC (Annex IAI). Hirschmanniella species are root endoparasites uniquely adapted to aquatic environments. Most species are reported from tropical regions. Monocotyledons including aquatic plants are main hosts and some Hirschmanniella species are important pests of rice. Plants for planting are potential pathways for entry. Hirschmanniella species are frequently intercepted on imported aquarium plants. Measures are available to avoid entry. Environmental conditions in greenhouses and potentially in rice production areas of the EU are suitable for establishment. The nematode may be spread with irrigation, tools or plants for planting. Hirschmanniella species were categorised into four groups. The first group includes species reported as pests of crop plants; those satisfy all the criteria that are within the remit of EFSA to assess to be regarded as Union quarantine pests. The second group includes species that are not reported to cause economic damage to crop plants; those species do not satisfy all the criteria to be regarded as Union quarantine pests. Uncertainty exists whether species in this group can cause damage once introduced into the EU. The third group includes species that are known to be present in the EU and do not cause damage; they do not satisfy the criteria to be regarded as Union quarantine pests or regulated non‐quarantine pests. The fourth group consists of H. gracilis only. This worldwide occurring species is present in the EU where it does not cause economic damage. It does not satisfy all the criteria to be regarded as a Union quarantine pest.
The EFSA Panel on Plant Health performed a pest risk assessment on Ditylenchus destructor, the potato rot nematode, for the EU. It focused the assessment of entry, establishment, spread and impact on ...two crops: potato (Solanum tuberosum) and tulip (Tulipa spp.). The main pathways for entry of D. destructor into the EU and for spread of this nematode within the EU are plants for planting, including seed potatoes and flower bulbs. These commodities are also the main targets for the assessment of the impact. A modelling approach was used to quantitatively estimate entry, spread and impact. Literature and expert judgement were used to estimate model parameters, taking into account uncertainty. A baseline scenario with current pest‐specific phytosanitary regulations was compared with alternative scenarios without those specific regulations or with additional risk reduction options. Further information is provided on the host range of D. destructor and on survival of the nematode in soil in the absence of hosts. The Panel concludes that the entry of D. destructor with planting material from third countries is small compared to the yearly intra‐EU spread of this nematode with planting material. Changes in pest‐specific regulations have little influence on entry of the pest as other non‐specific regulation already lead to a good level of protection against the introduction of the nematode into the pest risk assessment (PRA) area. It is also concluded that the whole PRA area is suitable for establishment of D. destructor, but there is insufficient information to make a statement on the persistence of newly introduced populations in the entire PRA area. Impacts of this nematode on the quantity and quality of potato are considered negligible. The impact on flower bulb production in the EU is considered as very low.
The EFSA Panel on Plant Health performed a pest categorisation of non-EU isolates of Beet curly top virus (BCTV) for the European Union territory. The virus causes severe diseases in beet, tomatoes ...and pepper crops, occurs predominantly in warm and dry zones and is reported from many countries outside the EU in particular from western USA and Mexico. New data from complete virus genomes make BCTV a well characterised virus species of which currently 11 strains are known and for which diagnostic methods are available. BCTV has a very broad host range of more than 300 species some of which may remain symptomless. Aside from vegetative propagation of infected plants, the only mode of BCTV transmission and spread is by the leafhopper Circulifer tenellus which efficiently transmits the virus in a persistent mode and which is present in several southern EU Member States. No current reports of BCTV presence in the EU exist and because of doubts about the accuracy of older reports, BCTV likely is absent from the EU territory. BCTV can enter into the EU with viruliferous insects and with imports of plants not subject to specific EU regulation. Because both the virus and its vector have a wide host range, BCTV is expected to establish and spread in the Member States where its vector is present and to cause severe diseases in sugar beet and tomato as well as in other crops. Overall, BCTV non-EU isolates meet all the criteria evaluated by EFSA to qualify as a Union quarantine pest and do not meet the criterion of presence in the EU to qualify as a Union regulated non-quarantine pest (RNQP). The main uncertainties concern (1) the presence of BCTV in the EU, (2) the distribution of C. tenellus and (3) the main commodities for virus entry.
Pest categorisation of Tecia solanivora Jeger, Michael; Bragard, Claude; Caffier, David ...
EFSA journal,
January 2018, Volume:
16, Issue:
1
Journal Article
Peer reviewed
Open access
The Panel on Plant Health performed a pest categorisation of Tecia solanivora (Lepidoptera: Gelechiidae) the Guatemalan potato tuber moth, for the EU. T. solanivora is a well‐defined species which ...feeds exclusively on Solanum tuberosum. It was first described from Costa Rica in 1973 and has spread through Central America and into northern South America via trade of seed potatoes. It has also spread to Mexico and the Canary Islands and most recently to mainland Spain where it is under official control in Galicia and Asturias. Potatoes in the field and storage can be attacked. Some authors regard T. solanivora as the most important insect pest of potatoes globally. T. solanivora is currently regulated by Council Directive 2000/29/EC, listed in Annex II/AI as Scrobipalpopsis solanivora. Larvae feed and develop within potato tubers; infested tubers therefore provide a pathway for pest introduction and spread, as does the soil accompanying potato tubers if it is infested with eggs or pupae. As evidenced by the ongoing outbreaks in Spain, the EU has suitable conditions for the development and potential establishment of T. solanivora. The pest could spread within the EU via movement of infested tubers; adults can fly and disperse locally. Larval feeding destroys tubers in the field and in storage. In the warmer southern EU, where the development would be fastest, yield losses would be expected in potatoes. Measures are available to inhibit entry via traded commodities (e.g. prohibition on the introduction of S. tuberosum). T. solanivora satisfies all of the criteria assessed by EFSA to satisfy the definition of a Union quarantine pest. It does not satisfy EU regulated non‐quarantine pest (RNQP) status because it is under official control. There are uncertainties over the effectiveness of preventing illegal imports via passenger baggage and the magnitude of potential impacts in the cool EU climate.
The 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 Panel concludes 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.
The Panel on Plant Health performed a pest categorisation of the soil‐borne fungus Fusarium oxysporum f. sp. albedinis, the causal agent of Fusarium wilt of date palm, for the EU. The identity of the ...pest is well established and reliable methods exist for its detection/identification. The pest is listed in Annex IIAI of Directive 2000/29/EC and is not known to occur in the EU. Fusarium oxysporum f. sp. albedinis is present in Morocco, Algeria and Mauritania. Its major host is Phoenix dactylifera, which is the only Phoenix species known to be affected by the pest. Uncertainty exists about the host status of Lawsonia inermis, Medicago sativa and Trifolium spp. cultivated as intercrops in the infested areas and reported as being symptomless carriers of the pest. The pest could potentially enter the EU on host plants and soil/growing media originating in infested Third countries. The current pest distribution and climate matching suggest that the pest could establish and spread in the EU wherever the host is present. In the infested areas, the pest causes vascular wilt resulting in yield/quality losses and plant death. It is expected that pest introduction and spread in the EU could impact date production. The pest is expected to have high environmental consequences in the Elche area (Spain), which is a UNESCO World Heritage Site, as well as other EU areas where P. dactylifera is grown as an amenity tree. Current EU phytosanitary measures are not fully effective at mitigating the risk of introduction and spread of the pest in the EU. Fusarium oxysporum f. sp. albedinis meets all the criteria assessed by EFSA for consideration as potential Union quarantine pest. As the pest is not known to occur in the EU, this criterion to consider it as Union regulated non‐quarantine pest is not met.
Agrobacterium vitis causes common grape vine (Vitis vinifera L.) crown gall disease that destroyed a lot of Slovenian vineyards more than a decade ago. Eighty isolates of Agrobacterium spp. collected ...during monitoring in 2006 were identified as A. vitis and A. tumefacies by pehA and multiplex PCR method. Tumor-inducing capacity of these strains was assessed on test plants and with PCR methods for detection of the Ti plasmid responsible for tumor induction. With VCF3/VCR3 primer pair six false negatives and no false positives were detected. The high genetic diversity of pathogenic Agrobacterium spp. strains affects the performance of molecular methods, thus biological test should be performed where results from molecular methods are doubtful.
Grapevine leafroll disease is one of the most severe viral diseases of grapevine caused by Grapevine leafroll-associated viruses (GLRaVs). Physiological processes were monitored on grapevines with ...single (GLRaV-1) and mixed (GLRaV-1 and GLRaV -3) viral infection under greenhouse conditions from June to September, in vegetation period 2014. In the mid of the season (July) negative effects of the virus infections on physiological processes were more severe in mixed than in single infection. The net-photosynthesis (Pn) of the leaves infected with GLRaV-1 and GLRaV-3 reached only a half of the Pn in GLRaV-1 infected grapevines. Similar reduction was found for stomatal conductance, transpiration and parameters related to photochemical efficiency (electron transport rate).
The Panel on Plant Health performed a pest categorisation of the great spruce bark beetle, Dendroctonus micans (Kugelann), (Coleoptera: Curculionidae, Scolytinae), for the EU. D. micans is a ...well‐defined and distinguishable species, recognised mainly as a pest of spruce (Picea spp.) and pine (Pinus spp.) in Eurasia. Attacks on other conifers (Abies spp., Larix decidua, Pseudotsuga menziesii) are also reported. Supposedly originating from north‐eastern Eurasia, D. micans has spread westward and is now distributed throughout the EU (22 Member States). It is a quarantine pest listed in Annex IIB of Council Directive 2000/29/EC for Greece, Ireland and the United Kingdom (Northern Ireland, Isle of Man and Jersey) as protected zones. Wood, wood products, bark and wood packaging material of the conifers genera listed as hosts are considered as the main pathways for the pest, which is also able to disperse several kilometres by flight. The sib‐mating habits of the species allow each single female to start a new colony on her own. The pest's wide current geographic range suggests that it is able to establish anywhere in the EU where its hosts are present. The beetles attack living trees and usually complete their life cycle without killing their host, except under epidemic conditions at the limits of their distribution range, where hundreds of thousands of trees can be killed. Sitka spruce (Picea sitchensis) is particularly susceptible. Biological control using the very specific predatory beetle, Rhizophagus grandis, is a widespread and efficient option that has been implemented in all areas suffering from outbreaks. It is complemented by sanitary thinning or clear‐felling. All criteria assessed by EFSA for consideration as potential protected zone quarantine pest were met. The criteria for considering D. micans as a potential regulated non‐quarantine pest are not met since plants for planting are not the main pathway.
The Plant Health Panel reviewed the paper by Guarnaccia et al. () and compared their findings with previous predictions on the establishment of Phyllosticta citricarpa. Four species of Phyllosticta ...were found by Guarnaccia et al. () in Europe. P. citricarpa and P. capitalensis are well‐defined species, with P. citricarpa recorded for the first time in Europe, confirming predictions by Magarey et al. () and EFSA (2008, 2014, 2016) that P. citricarpa can establish in some European citrus‐growing regions. Two new species P. paracitricarpa and P. paracapitalensis were also described, with P. paracitricarpa (found only in Greece) shown to be pathogenic on sweet orange fruits. Genotyping of the P. citricarpa isolates suggests at least two independent introductions, with the population in Portugal being different from that present in Malta and Italy. P. citricarpa and P. paracitricarpa were isolated only from leaf litter in backyards. However, since P. citricarpa does not infect or colonise dead leaves, the pathogen must have infected the above living leaves in citrus trees nearby. Guarnaccia et al. () considered introduction to be a consequence of P. citricarpa having long been present or of illegal movement of planting material. In the Panel's view, the fruit pathway would be an equally or more likely origin. The authors did not report how surveys for citrus black spot (CBS) disease were carried out, therefore their claim that there was no CBS disease even where the pathogen was present is not supported by the results presented. From previous simulations, the locations where Guarnaccia et al. () found P. citricarpa or P. paracitricarpa were conducive for P. citricarpa establishment, with number of simulated infection events by pycnidiospores comparable to sites of CBS occurrence outside Europe. Preliminary surveys by National Plant Protection Organisations (NPPOs) have not confirmed so far the findings by Guarnaccia et al. () but monitoring is still ongoing.
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