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.
Following a request from the European Commission, the EFSA Plant Health Panel analysed a dossier submitted by the Italian Authorities to reach a conclusion on the status of Vitis spp., Citrus spp. ...and Quercus ilex as hosts for Xylella fastidiosa strain CoDiRO. The Panel acknowledges the difficulty to provide compelling evidence for non‐susceptibility of a particular plant species. In the case of Vitis spp., the Panel considers that convergent lines of evidence provide sufficient demonstration that at least the tested varieties (Cabernet Sauvignon, Negroamaro and Primitivo) do not support a systemic infection by the CoDiRO strain. The extension of this conclusion to other grapevine varieties and to Vitis species other than Vitis vinifera is associated with significant uncertainties. The Panel therefore considers it premature to conclude that all Vitis species are unable to support a CoDiRO systemic infection. In addition, although the local accumulation detected in the mechanical inoculation experiments may represent an artefact, the Panel considers it premature to conclude that the tested grapevine varieties are not able to support local multiplication of the CoDiRO strain. Further extension of this conclusion to other grapevine varieties and to non‐vinifera species is also premature. For Citrus spp., the data available provide coherent and converging lines of evidence suggesting that sweet orange may be a non‐systemic host of strain CoDiRO. However, given the limited scope of the data available on other species, the Panel considers it premature to reach a general conclusion for all Citrus species. The potential epidemiological consequences of non‐systemic infections remain to be fully evaluated. In the case of Quercus ilex, the Panel concludes that the limited data available provides some evidence suggesting that it may not be a systemic host of the CoDiRO strain, but that it would be premature to consider this tentative conclusion as firmly established.
Following a request from the European Commission, the EFSA Plant Health Panel analysed a dossier submitted by Costa Rica Authorities to reach a conclusion on the host status of Phoenix roebelenii for ...Xylella fastidiosa. The Panel wishes first to stress the difficulties faced in providing compelling evidence for the non‐susceptibility status of any particular plant species. The Panel acknowledges that the listing of P. roebelenii as a host of X. fastidiosa rests on a single report from California. Because isolation of X. fastidiosa from some hosts can be difficult, the Panel considers that the failure to isolate X. fastidiosa from P. roebelenii cannot be used to totally discard the detection of X. fastidiosa by ELISA and PCR. The Panel concludes that the detection of X. fastidiosa by two independent techniques provides sufficient evidence, although not totally conclusive, for the listing of P. roebelenii as a X. fastidiosa host plant. Concerning the survey data provided in the Costa Rican dossier, the Panel wishes to stress that such surveys cannot demonstrate the non‐host status but can only provide a probability bound, upper estimate of the proportion of infected plants in the field. In the present case, and assuming all survey parameters to be optimal, the 95% confidence incidence threshold obtained is 0.2%, leaving the possibility that close to 25,000 P. roebelenii plants could be infected but undetected in the country. Accepting a scenario of local, non‐systemic infection of P. roebelenii by X. fastidiosa would further increase uncertainties. In addition, the absence of data on the vector infection pressure further affects the ability to derive meaningful information on the P. roebelenii host status from the survey data. Appropriately conducted mechanical and/or vector‐mediated inoculation experiments are critical to reach a more solid conclusion on the X. fastidiosa host status of P. roebelenii.
The origin of olfactory stimuli involved in the host microhabitat location in Cotesia flavipes, a parasitoid of stem-borer larvae, was investigated in a Y-tube olfactometer. The response of female C. ...flavipes towards different components of the plant-host complex, consisting of a maize plant infested with two or more larvae of the stem borer Chilo partellus, was tested in dual-choice tests. The concealed lifestyle of the stem-borer larvae did not limit the emission of volatiles attractive to a parasitoid. A major source of the attractive volatiles from the plant-host complex was the stem-borer-injured stem, including the frass produced by the feeding larvae. Moreover, the production of volatiles attractive to a parasitoid was not restricted to the infested stem part but occurs systemically throughout the plant. The uninfested leaves of a stem-borer-infested plant were found to emit volatiles that attract female C. flavipes. We further demonstrate that an exogenous elicitor of this systemic plant response is situated in the regurgitate of a stem-borer larva. When a minor amount of regurgitate is inoculated into the stem of an uninfested plant, the leaves of the treated plant emit volatiles that attract female C. flavipes
A viscous formulation based on castor oil containing the pyrethroid insecticide cyfluthrin and E8, E10‐dodecadienol, the main component of the codling moth sex pheromone, (Cydia pomonella L.: ...Tortricidae, Olethreutinae) was developed. The insecticidal performance of the formulation was evaluated in the laboratory using a tarsal‐contact bioassay. The pheromone dosage required to attract male moths to the formulation was determined in behavioural tests performed in a wind tunnel. The efficacy of formulations applied to seedlings of the host plant was further investigated in glasshouse experiments conducted with male moths in small wire‐gauze cages. The laboratory tests resulted in a formulation for preliminary field trials containing 4% cyfluthrin and 0.1% pheromone. During the 1995 growing season, experiments were conducted in apple orchards at three locations in Germany. The formulation was first applied to the bark of apple trees (Malus domestica) in mid May and then again in late July. A good level of control, comparable with a spray treatment using the insect growth regulator Alsystin was achieved. The potential of the attract and kill strategy, combining selective attraction of a pest species with the efficacy associated with a pyrethroid insecticide treatment, as a means of controlling the codling moth in commercial apple growing, is discussed.
EFSA has carried out a public consultation on the draft Guidance of the EFSA Scientific Panel on Plant Health (PLH Panel) on commodity risk assessment for the evaluation of high risk plants dossiers ...with the aim of collecting input from the scientific community and all interested parties. Article 42 of the European Regulation (EU) 2016/2031, on the protective measures against pests of plants, introduces the concept of ‘high risk plants, plant products and other objects’ that are identified on the basis of a preliminary assessment to be followed by a commodity risk assessment. The draft Guidance provided the methodology to be followed when performing a commodity risk assessment for high risk commodities. Following international standards on pest risk analysis this Guidance describes a two‐step approach for the assessment of pest risk associated with a specified commodity. In the first step, pests associated with the commodity that may require risk mitigation measures are identified. In the second step, the overall efficacy of proposed risk reduction options for each pest is evaluated. A conclusion on the pest freedom status of the commodity is achieved. The method allows key uncertainties to be identified. Following the endorsement of the draft Guidance by the PLH Panel, the public consultation was launched on 14 December 2018 and closed on 24 January 2019. EFSA received 56 comments on the draft Guidance from four interested parties. This technical report on the outcome of the public consultation on the draft Guidance summarises the comments received during the public consultation and presents the responses of the PLH Panel. The PLH Panel prepared an updated version of the draft Guidance taking into account the comments received. The Guidance was adopted at the PLH Panel plenary meeting on 28 March 2019, (EFSA PLH panel, 2019) and is published in the EFSA Journal.
BEHAVIORAL ECOLOGY OF PARASITOIDS AND BIOLOGICAL CONTROLBehavioral ecology is concerned with the evolution of adaptive behavior in relation to ecological circumstances (Krebs and Davies, 1981). ...Because an individual’s success at surviving and reproducing depends on its behavior, natural selection will favor animals with efficient foraging strategies. Insect parasitoids forage for hosts that directly support the development of their progeny. The lifetime reproductive success of a female parasitoid is depended on the number and quality of hosts located and utilized in her lifetime. Thus, host foraging in parasitoids is closely linked to fitness, which make parasitoids ideal organisms to study the adaptive value of foraging decisions (Godfray, 1994), These foraging decisions include for example where to search for hosts and for how long (e.g. Van Alphen and Vet, 1986; Stephens and Krebs, 1986; Vee et al., 1995). Once a host is located the female has to decide whether the host should be accepted and if so, how many eggs to lay and in which sex ratio (e.g. Waage, 1986; Godfray, 1987; Van Alphen and Visser, 1990). The behavioral ecology of insect parasitoids is not only interesting from a theoretical evolutionary perspective, but also from an applied perspective, because parasitoids are frequently used in biological control of insect pests.In biological control parasitoid establishment and parasitism rates are often variable. For biological control to be a retiable and efficient method insight is needed in the foraging behavior of the natural enemy used. The ability of parasitoids to locate and attack hosts is a key determinant of how well a given parasitoid population performs. Thus variability in this host-location abiliry can be a major source of inconsistent results in biological control with parasitoids.The need to improve the scientific basis of biological control is increasingly being expressed (Van Lenteren, 1980, Mackaver et al, 1990). A more complete understanding of the ecology and behavior of natural enemies is critical when we want to increase the reliabiliry and predictability of biological control with insect parasitoids (Lewis et al., 1990; Luck, 1990). Behavioral ecology theory forms a suitable framework to design research programs for biological control (Waage, 1990; Luck, 1990), such as the development of selection criteria for biological control agents, the improvement of mass-rearing of selected natural enemies and the evaluation of success or failures of released natural enemies.VARIATION IN PARASITOID BEHAVIORIntraspecific variation in parasitoid physiology and behavior has long been speculated to be one of the factors responsible for variability in effectiveness of biological control. For instance, biological control workers frequently refer to races, strains or biotypes that differ in biological traits considered to be important for successful biological control (e.g. Gonzalez et al., 1979; Caltagirone, 1985). Failure of a biological control project may result from an incorrect identification of the species involved or a selection of an inappropriate strain.Especially in augmentive (seasonal) releases of laboratory reared parasitoids it is essential that a strain is selected with the highest efficiency against the target pest species in a given environment to minimize seasonal production costs. Among the criteria used for this selection are traits relared to reproductive capacity and searching activity (e.g. Chambers, 1977; Bigler, 1989; van Lenteren, 1991).
Seaweeds are presently explored as an alternative source to meet the future protein demand from a growing world population with an increasing welfare level. Present seaweed research largely focuses ...on agri-technical and economic aspects. This paper explores directions for optimizing the cultivation, harvesting, transport and drying of seaweed from an environmental point of view. An environmental life cycle assessment (LCA) and detailed sensitivity analysis was made for two different system designs. One system design is featuring one layer of cultivation strips (four longlines side by side) interspaced with access corridors. The other system design is featuring a doubling of cultivation strips by dual layers in the water column. Impact profiles and sensitivity analysis showed that the most important impacts came from drying the harvested seaweed, and from the production of the chromium steel chains and polypropylene rope in the infrastructure. This indicates that caution should be used when designing cultivation systems featuring such materials and processes. Furthermore, the high-density productivity of the dual layer system decreases absolute environmental impacts and so found to be a little more environmentally friendly from a life cycle perspective.
•Designs of two macroalgae cultivation strip systems featuring four longlines side by side interspaced with access corridors•Life cycle environmental impacts of the cultivation, harvest, transport and drying of seaweed biomass•Most important process in terms of environmental impacts was found to be drying•Most important material components identified as stainless-steel chains and polypropylene ropes•Higher productivity of dual layer system makes it a little more environmentally friendly from a life cycle perspective
PURPOSE: Intensive striped catfish production in the Mekong Delta has, in recent years, raised environmental concerns. We conducted a stakeholder-based screening life cycle assessment (LCA) of the ...intensive farming system to determine the critical environmental impact and their causative processes in producing striped catfish. Additional to the LCA, we assessed water use and flooding hazards in the Mekong Delta. MATERIALS AND METHODS: The goal and scope of the LCA were defined in a stakeholder workshop. It was decided there to include all processes up to the exit-gate of the fish farm in the inventory and to focus life cycle impact assessment on global warming, acidification, eutrophication, human toxicity, and marine (MAET) and freshwater aquatic ecotoxicity (FWET). A survey was used to collect primary inventory data from 28 farms on fish grow-out, and from seven feed mills. Hatching and nursing of striped catfish fingerlings were not included in the assessment due to limited data availability and low estimated impact. Average feed composition for all farms had to be applied due to limitation of budget and data availability. RESULTS AND DISCUSSION: Feed ingredient production, transport and milling dominated most of the impact categories in the LCA except for eutrophication and FWET. Most feed ingredients were produced outside Vietnam, and the impact of transport was important. Because of the screening character of this LCA, generic instead of specific inventory data were used for modelling feed ingredient production. However, the use of generic data is unlikely to have affected the main findings, given the dominance of feed production in all impact categories. Of the feed ingredients, rice bran contributed the most to global warming and acidification, while wheat bran contributed the most to eutrophication. The dominance of both was mainly due to the amounts used. Fishmeal production, transport and energy contributed the most to MAET. The biggest impacts of grow-out farming in Vietnam are on eutrophication and FWET. Water nutrient discharge from grow-out farming was high but negligible compared with the natural nutrient content of the Mekong River. The discharge from all grow-out farms together hardly modified river water quality compared with that before sector expansion. CONCLUSIONS: Feed production, i.e. ingredient production and transport and milling, remains the main contributor to most impact categories. It contributes indirectly to eutrophication and FWET through the pond effluents. The environmental impact of Pangasius grow-out farming can be reduced by effectively managing sludge and by using feeds with lower feed conversion ratio and lower content of fishery products in the feed. To consider farm variability, a next LCA of aquaculture should enlist closer collaboration from several feed-milling companies and sample farms using their feeds. Future LCAs should also preferably collect specific instead of generic inventory data for feed ingredient production, and include biodiversity and primary production as impact categories.
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