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Intercropping, growing two or more crop species in the same field, is a practice that can contribute to ecological intensification of agriculture. Intercropping has been shown to increase productivity in low phosphorus (P) soils compared to sole crops. The ecological mechanisms underlying these benefits mainly include complementarity and facilitation with respect to resource acquisition. The contribution of these mechanisms to the yield benefit of intercropping probably depends on crop species traits, soil nutrient availability and agronomic practices. This thesis aims to contribute to the design of intercropping systems for improved P acquisition and yield gain by testing the resource partitioning hypothesis (dissimilarity in P acquisition traits among plant species leads to enhanced P uptake by mixtures of crop species compared to sole crops), and by quantifying the absolute yield gain of intercrops and the effect of agronomic practices. It presents results from empirical studies and meta-analyses.It appeared that the conditions under which the P resource partitioning hypothesis can be tested are limited. The tested crop species had inconsistent abilities to access the sparingly soluble Ca-bound P, phytate P, P-coated Fe(hydr)oxide, and competitive inequality between them largely determined the interaction. In a pot experiment with low P soils containing a mixture of organic and inorganic P sources, complementarity and facilitation did not result in increased P uptake by species mixtures, because P uptake was also affected by the competitive equality of species in the mixture. In a field experiment on a low P soil, complementarity and facilitation with respect to P uptake occurred in millet/chickpea relay strip intercropping, but they were not the main drivers for overyielding. In the subsequent meta-analysis on intercropping at the field level, the absolute yield gain of intercropping was mainly attributed to a positive complementarity effect, an outcome of any m

Xylella fastidiosa is the causal agent of plant diseases that cause massive economic damage. In 2013, a strain of the bacterium was, for the first time, detected in the European territory (Italy), causing the Olive Quick Decline Syndrome. We simulate future spread of the disease based on climatic-suitability modeling and radial expansion of the invaded territory. An economic model is developed to compute impact based on discounted foregone profits and losses in investment. The model projects impact for Italy, Greece, and Spain, as these countries account for around 95% of the European olive oil production. Climatic suitability modeling indicates that, depending on the suitability threshold, 95.5 to 98.9%, 99.2 to 99.8%, and 84.6 to 99.1% of the national areas of production fall into suitable territory in Italy, Greece, and Spain, respectively. For Italy, across the considered rates of radial range expansion the potential economic impact over 50 y ranges from 1.9 billion to 5.2 billion Euros for the economic worst-case scenario, in which production ceases after orchards die off. If replanting with resistant varieties is feasible, the impact ranges from 0.6 billion to 1.6 billion Euros. Depending on whether replanting is feasible, between 0.5 billion and 1.3 billion Euros can be saved over the course of 50 y if disease spread is reduced from 5.18 to 1.1 km per year. The analysis stresses the necessity to strengthen the ongoing research on cultivar resistance traits and application of phytosanitary measures, including vector control and inoculum suppression, by removing host plants.

Aim: Cereal-legume intercropping can result in yield gains compared to monocrops. We aim to identify the combination of crop traits and management practices that confer a yield advantage in strip intercropping. Methods: We developed a novel, parameter-sparse process-based crop growth model (Minimalist Mixture Model, M3) that can simulate strip intercrops under well-watered but nitrogen limited growth conditions. It was calibrated and validated for spring wheat (Triticum aestivum) and spring faba bean (Vicia faba) grown as monocrops and intercrops, and used to identify the most suitable trait combinations in these intercrops via sensitivity analyses. Results: The land equivalent ratio of intercrops was greater than one over a wide range of nitrogen fertilizer levels, but transgressive overyielding, with total yield in the intercrop greater than that of either sole crop, was only obtained at intermediate nitrogen applications. We ranked the local sensitivities of the individual yields of wheat and faba bean of the whole intercrop under various nitrogen input levels to various crop traits. Conclusions: The total intercrop yield can be improved by selecting specific traits related to phenology of both species, as well as light use efficiency of faba bean and, under high nitrogen applications, of wheat. Changes in height-related crop traits affected individual yields of species in intercrops but not the total intercrop yield.

Intercropping is known to increase the efficiency of land use, but no meta-analysis has so far been made on the yield gain of intercropping compared to sole cropping in terms of absolute yield per unit area. Yield gain could potentially be related to a relaxation of competition, due to complementarity or facilitation, and/or to the competitive dominance of the higher yielding species. The contributions of competitive relaxation and dominance were here estimated using the concepts of complementarity effect (CE) and selection effect (SE), respectively. We compiled a dataset on intercropping of grain-producing crops from China, a hotspot of strip intercropping in the world. We quantified the yield gain and its components and analysed the contribution to yield gain of species traits (C3, C4, legume, non-legume), complementarity in time and nutrient input. Total yield in intercrops exceeded the expected yield, estimated on the basis of sole crop yields, by 2.14 ± 0.16 Mg ha−1 (mean ± standard error). Ninety percent of this yield gain was due to a positive CE while the remaining 10 % was due to SE. The net yield gain increased with temporal niche differentiation (TND) which is the proportion of the total growing period of the crop mixture during which species grow alone. The mechanism underlying yield gain shifted from competitive dominance of the higher yielding species when there was more overlap in growth period between the two species, to competitive relaxation when there was less overlap, while competitive relaxation remained the major component of the yield gain. The yield gain was substantially greater in intercrops with maize than in intercrops without maize, but there was no difference in yield gain between systems with and without legumes. The yield gain increased with nitrogen (N) input in maize/C3-cereal intercrops but not in cereal/legume intercrops, illustrating the ability of legumes to compensate for low N input, and highlighting the need for N input for h

Intercropping is the cultivation of multiple crop species on the same land. Relay strip intercropping is an intercropping system in which the component species are grown in strips, while the growing periods of the crop species overlap only partially. The effects of strip width on yields in relay-strip intercropping are still poorly understood. Here in a case study on wheat-maize relay intercropping a simple strip intercropping model was applied to quantify intercropping performance as a function of a wide range of strip widths. Simulations showed that (1) the optimum strip width is less than 1 meter and (2) benefits of intercropping rapidly drop as strips become wider. Most previous experimental work was also done at narrow configurations, with strips less than 3 meters wide. Benefits of intercropping may therefore be less than what would be expected from experiments if narrow configurations are not attainable because of lack of mechanisation. All optimised strip configurations showed a Land Equivalent Ratio (LER) larger than 1 indicating benefits of intercropping, irrespective of assumptions that were made on radiation use efficiency in intercropped species as compared to sole crops. At current prices of wheat and maize, however, intercropping gross margin exceeded sole cropping gross margin only if the intercrop RUE was larger than sole crop RUE for both species. This study shows that strip crop growth models can be used to specify needs for future machinery, that will enable farmers to attain benefits from intercropping.

Xylella fastidiosa is the causal agent of plant diseases that cause massive economic damage. In 2013, a strain of the bacterium was, for the first time, detected in the European territory (Italy), causing the Olive Quick Decline Syndrome. We simulate future spread of the disease based on climatic-suitability modeling and radial expansion of the invaded territory. An economic model is developed to compute impact based on discounted foregone profits and losses in investment. The model projects impact for Italy, Greece, and Spain, as these countries account for around 95% of the European olive oil production. Climatic suitability modeling indicates that, depending on the suitability threshold, 95.5 to 98.9%, 99.2 to 99.8%, and 84.6 to 99.1% of the national areas of production fall into suitable territory in Italy, Greece, and Spain, respectively. For Italy, across the considered rates of radial range expansion the potential economic impact over 50 y ranges from 1.9 billion to 5.2 billion Euros for the economic worst-case scenario, in which production ceases after orchards die off. If replanting with resistant varieties is feasible, the impact ranges from 0.6 billion to 1.6 billion Euros. Depending on whether replanting is feasible, between 0.5 billion and 1.3 billion Euros can be saved over the course of 50 y if disease spread is reduced from 5.18 to 1.1 km per year. The analysis stresses the necessity to strengthen the ongoing research on cultivar resistance traits and application of phytosanitary measures, including vector control and inoculum suppression, by removing host plants

Overreliance on synthetic insecticides in global agriculture is the outcome of a “pesticide treadmill,” in which insecticide-induced pest resistance development and the depletion of beneficial insect populations aggravate farmers’ pesticide dependencies. Examples of the pesticide treadmill have been witnessed repeatedly over the past seven decades, prompting the question whether the rapid uptake and usage patterns of neonicotinoid insecticides and their associated environmental impact are in accordance with this recurrent phenomenon. We hypothesize a conceptual framework in which treadmills are enforced by enabling or disabling drivers within four domains: pest management decisions at the farm level, characteristics of farming landscapes, science and technology, and societal demands. These drivers then tend to create a self-enforcing pesticide “lock-in.” We then analyze several post-1950s historical case studies with reference to this framework, e.g., those involving sprays of the highly hazardous DDT and methyl-parathion, in which the pesticide treadmill was initiated, sustained, and broken, and compare this with current patterns in neonicotinoid use. Historical case studies further illustrate how treadmills occur in three phases in which (i) a limited number of insecticides are routinely used, (ii) resistance development of pests results in the increased crop injury, prompting increased frequency of applications with a wider range of products, (iii) breaking out of the pesticide “lock-in” by policy change and adoption of alternative technologies that lowered chemical inputs and improved agro-ecosystem functioning. The analysis shows similarities as well as differences between neonicotinoid usage patterns and historic pesticide treadmills, and provides guidance on how to effectively avoid or dismantle pesticide treadmills in global agriculture.

How insects promote crop pollination remains poorly understood in terms of the contribution of functional trait differences between species. We used meta-analyses to test for correlations between community abundance, species richness and functional trait metrics with oilseed rape yield, a globally important crop. While overall abundance is consistently important in predicting yield, functional divergence between species traits also showed a positive correlation. This result supports the complementarity hypothesis that pollination function is maintained by non-overlapping trait distributions. In artificially constructed communities (mesocosms), species richness is positively correlated with yield, although this effect is not seen under field conditions. As traits of the dominant species do not predict yield above that attributed to the effect of abundance alone, we find no evidence in support of the mass ratio hypothesis. Management practices increasing not just pollinator abundance, but also functional divergence, could benefit oilseed rape agriculture.

How insects promote crop pollination remains poorly understood in terms of the contribution of functional trait differences between species. We used meta-analyses to test for correlations between community abundance, species richness and functional trait metrics with oilseed rape yield, a globally important crop. While overall abundance is consistently important in predicting yield, functional divergence between species traits also showed a positive correlation. This result supports the complementarity hypothesis that pollination function is maintained by non-overlapping trait distributions. In artificially constructed communities (mesocosms), species richness is positively correlated with yield, although this effect is not seen under field conditions. As traits of the dominant species do not predict yield above that attributed to the effect of abundance alone, we find no evidence in support of the mass ratio hypothesis. Management practices increasing not just pollinator abundance, but also functional divergence, could benefit oilseed rape agriculture.

Xylella fastidiosais the causal agent of plant diseases which cause massive economic damage (Almeida, 2016; Chatterjee et al., 2008). In 2013, a strain of X.fastidiosasubsp. paucawas for the first time detected in Italian olives (European Food Safety Authority, 2015; Saponari et al., 2016). Here, we simulate future spread of the bacteria based on climatic suitability modelling and an assumption of radial range expansion. An economic model computes impacts by accounting for discounted foregone profits and losses in investment. The model computes impacts for Italy, Greece and Spain as these countries account for around 95 per cent of the European production (Eurostat, 2016). Climatic suitability modelling indicates that, depending on the suitability threshold, 92.5 to 95.4,88.6 to 89.5 and 85.8 to 98.5 per cent of the national areas of production fall into suitable territory in Italy, Greece and Spain, respectively. Across the elicited rates of radial range expansion (Bragard et al., 2019), the potential economic impact over 50 years rangesfrom 3.58 to 8.69 billion euro if replanting with resistant varieties is not feasible. If replanting is feasible, the impact ranges from 2.00 to 4.13 billion euro. Depending on whether or not replanting is feasible, between 0.67 and 1.64 billion euro can be saved over the course of 50 years if the spread is reduced from 5.18km to 1.1km per year (50% and 5% percentile of elicited spread rate). The analysis highlights the major economic benefits of replanting with resistant olive cultivarsand spread control. This stresses the necessity of strengtheningthe ongoing research on resistance traits and vector control.

Following a request from the European Commission, the EFSA Panel on Plant Health performed a pest categorisation of Clavibacter sepedonicus, a well-defined and distinguishable bacterial plant pathogen of the family Microbacteriaceae. C. sepedonicus causes bacterial ring rot of potato and is reported from North America, Asia and Europe. The bacterium is mostly tuber transmitted, but it can also enter host plants through wounds or via contaminated equipment. C. sepedonicus is regulated in Council Directive2000/29/EC (Annex IAII, as Clavibacter michiganensis subsp. sepedonicus) as a harmful organism whose introduction into the EU is banned. In addition, Council Directive 1993/85/EEC concerns the measures to be taken within EU Member States (MS) against C. sepedonicus to (a) detect it and determine its distribution, (b) prevent its occurrence and spread, and (c) control it with the aim of eradication. The pest is present in several EU MS, but in all cases with a restricted distribution and under official control. C. sepedonicus could enter the EU and spread primarily via host plants for planting (i.e. potato tubers).The pest could establish in the EU, as the main host (potato) is commonly grown and climatic conditions are favourable. Direct potato losses following infection by C. sepedonicus can be substantial and are due to the destruction of the vascular tissue, wilting of the plant and rotting of the tubers. Infected hosts canremain asymptomatic. The main knowledge gaps are the geographic distribution of the pest and the host range. The criteria assessed by the Panel for consideration of C. sepedonicus as a potential quarantine pest are met, while, for regulated non-quarantine pests, the criterion on the widespread presence in the EU is not met.

Following a request from the European Commission, the EFSA Panel on Plant Health performed a pest categorisation of the Ralstonia solanacearum species complex (RSSC), a distinguishable cosmopolitan group of bacterial plant pathogens (including R. solanacearum, Ralstonia pseudosolanacearum and twosubspecies of Ralstonia syzygii) of the family Burkholderiaceae. The RSSC causes bacterial wilt in solanaceous crops, such as potato, tomato and pepper, but can also cause wilts in other important food crops such as fruit banana, plantain banana and cassava. The pest survives in the soil, and a number ofweed species can also be infected by the pest, often asymptomatically. The RSSC is regulated in Council Directive 2000/29/EC (Annex IAII) (indicated by its former name R. solanacearum, as delimited by Yabuuchi et al.) as a harmful organism whose introduction into the EU is banned. In addition, Council Directive 1998/57/EC (amended by Commission Directive 2006/63/CE) concerns the measures to be taken within EU Member States (MS) against the RSSC to (a) detect it and determine its distribution, (b) prevent its occurrence and spread, and (c) control it with the aim of eradication. The pest is present in several EU MS, but in all cases with a restricted distribution and under official control. Newphylotypes of the RSSC could enter the EU primarily via host plants for planting (including seed tubers).The pest could establish in the EU, as climatic conditions are favourable, hosts are common and the pathogen has high adaptability. Spread is mainly via plants for planting. Substantial crop losses in the EU would occur in the presence of RSSC epidemics. The RSSC is regarded as one of the world’s most important phytopathogenic bacteria due to its broad geographical distribution, large host range, aggressiveness, genetic diversity and long persistence in soil and water. The list of hosts and commodities for which the pest is regulated is incomplete due to the high diversity of hosts an

This datasets comprises data from 20 rice fields embedded in a gradient of landscapes from crop-dominated to semi-natural habitat-dominated, in the Jiangxi Province in China in 2014 and 2015. Each field was split into two plots: in one plot no pesticides were applied and in the other plot farmers applied pesticides according to their normal pest management practices. The dataset comprises information on the focal rice fields, the land use surrounding the focal rice fields, arthropod abundances and diversity, crop damage, an exclusion experiment to assess the potential of natural enemies to suppress pests, pest management practices and rice yield

Mixtures of plant species are often higher yielding due to species complementarities. Such effects may be beneficial to agriculture but are under-used in practice. It is therefore important to demonstrate beneficial effects of mixtures that are easy to implement for farmers. Here, we study yield in mixtures of agricultural cover crops. We hypothesized that the degree to which species express complementarity might be affected by the spatial configuration of the mixture. To test this hypothesis, we seeded mixtures using two configurations: (1) seed mixtures in each row (intimate mixing), and (2) different species in separate (alternate) rows (less intimate mixing). Three years field experiments were conducted to compare growth and N uptake by sole stands and the two pairwise mixture configurations of three cover crop species: vetch (Vicia sativa L.), bristle oat (Avena strigosa) and oilseed radish (Raphanus sativus L.). Shoot biomass production and N uptake were determined. Results were analysed using additive partitioning to determine the net biodiversity effect and its components. Mixtures, overall, accumulated significantly more shoot biomass and shoot N than the corresponding pure stands did on average; hence, the net biodiversity effect was positive. The yield benefit of mixtures (observed minus expected) was 0.66 t biomass ha−1 and 10.7 kg N ha-1 compared to an average sole cover crop of 2.58 t biomass ha−1 and 53.1 kg N ha−1. Contribution to the net biodiversity effect for biomass was, on average, equally divided between the complementarity effect and the selection effect. For N uptake, the net biodiversity effect was mostly realized through complementarity. Experimental year and species combination had a significant effect on biomass and N yield of mixtures. Mixtures containing vetch had the greatest gain in biomass compared to expectation. Whether within or between row mixing gave the highest yield and N uptake depended on species combination and year, but in

Following a request from the European Commission, the EFSA Panel on Plant Health performed a risk assessment of the entry of Pantoea stewartii subsp. stewartii on maize seed imported by the EU from the USA. This pest is a Gram-negative bacterium which causes Stewart's vascular wilt and leaf blight of maize (including sweet corn), a disease responsible for serious crop losses throughout the world. The following scenarios were considered: scenario A0 (current practice), scenario A1 (US request for modification of EU conditions for derogation), and scenario A2 (EU conditions for derogation). Results from the quantitative seed pathway model presented here show that, despite the low rates of plant-to-seed and seed-to-seedling transmission that have been reported in the literature for Stewart's wilt, given the amount of traded seed, and in the case of voluntary (i.e. not mandatory) inspections of seed production fields at the origin (i.e. scenario A0), the frequency of introducing the disease is in the order of magnitude of some hundred introductions per year (median number). The EU conditions for derogation would lead to a decrease in the likelihood of entry compared to scenarios A0 (about 10,000 times fewer introductions) and A1 (about 2,000 times fewer introductions). This protective effect is mainly due to the requirement that only genotypes resistant to Stewart's wilt are traded, with the additional field inspection (two instead of one per season) providing additional reassurance. The Panel also concluded that seed lot inspections, as currently carried out (e.g. with a sample of 400 seeds) are not likely to lead to a relevant reduction in the level of infected imported maize seed, given the low prevalence of Stewart's wilt at the origin. If, however, there is aggregation in infection among consignments, inspection would work towards identifying the highly infected consignments. Recently, outbreaks of Stewart's wilt have occurred in Italy (Emilia Romagna, Fr

The idea that noncrop habitat enhances pest control and represents a win-win opportunity to conserve biodiversity and bolster yields has emerged as an agroecological paradigm. However, while noncrop habitat in landscapes surrounding farms sometimes benefits pest predators, natural enemy responses remain heterogeneous across studies and effects on pests are inconclusive. The observed heterogeneity in species responses to noncrop habitat may be biological in origin or could result from variation in how habitat and biocontrol are measured. Here, we use a pest-control database encompassing 132 studies and 6,759 sites worldwide to model natural enemy and pest abundances, predation rates, and crop damage as a function of landscape composition. Our results showed that although landscape composition explained significant variation within studies, pest and enemy abundances, predation rates, crop damage, and yields each exhibited different responses across studies, sometimes increasing and sometimes decreasing in landscapes with more noncrop habitat but overall showing no consistent trend. Thus, models that used landscape-composition variables to predict pest-control dynamics demonstrated little potential to explain variation across studies, though prediction did improve when comparing studies with similar crop and landscape features. Overall, our work shows that surrounding noncrop habitat does not consistently improve pest management, meaning habitat conservation may bolster production in some systems and depress yields in others. Future efforts to develop tools that inform farmers when habitat conservation truly represents a win-win would benefit from increased understanding of how landscape effects are modulated by local farm management and the biology of pests and their enemies.

Increased resistance of emerging cotton leafworm Spodoptera litura in Pakistan and elsewhere to chemical insecticides calls for an alternative method of control. Isolates of nucleopolyhedrovirus (NPVs) of S. litura (SpltNPV) were collected from infected larvae in different ecological and geographic regions of Pakistan. The genotypic diversity of these SpltNPV isolates, their relation to geographical (spatial) distribution and cropping system, and their biological activity, in particular dose response, speed of kill and effects on feeding, were explored. The first Pakistani isolate, SpltNPV-Pak-BNG, was studied and compared to a presumable SpltNPV reference isolate, SpltNPV-G1. SpltNPV-Pak-BNG killed S. litura larvae significantly faster than SpltNPV-G1. Genetic analysis revealed that SpltNPV-Pak-BNG and SpltNPV-G1 are variants of different virus species, SpltNPV and SpliNPV, respectively. The biological activity of SpltNPV-Pak-BNG was determined in different instars larvae of S. litura showing that S. litura second or third instar larvae are preferred targets for S. litura control with SpltNPV-Pak-BNG in field crops. SpltNPV-Pak-BNG infected S. litura larvae with final polyhedrosis showed reduced food intake and weight gain. Interestingly, the mock-infected- larvae and the larvae that survived viral exposure, exhibited the same food consumption and weight gain. Twenty-two SpltNPV isolates were finally collected from S. litura from different agro-ecological regions and cropping systems in Pakistan to explore the genetic diversity of the virus on a spatial scale and explore its possible adaptation to region and crop systems. Among the SpltNPV-Pak isolates tested, isolates TAX1, SFD1, SFD2 and GRW1 were faster killing than other Pakistani isolates. All isolates were genotypic variants of a single SpltNPV ‘regiotype’, suggesting common recent ancestry, and distinct from the virus species type SpltNPV-G2. There was a strong correlation between geographic location and a S

Intercropping is the simultaneous cultivation of two or more crop species in the same field. It has been practiced in China for thousands of years. In recent decades, researchers in several disciplines have shown increasing interest in intercropping systems, due to their potential to generate higher yields and counteract resource degradation. Much research on intercropping has been carried out from an eco-physiological perspective in China in recent decades. However, a socio-economic analysis is critically needed to obtain more insight into why farmers adopt intercropping or not and why they shift from one production system to another. This study tries to fill this gap in the existing literature. Its main aim is to obtain a better understanding of farmers’ decisions on intercropping in China. The analysis conducted in two distinct perspectives. The first empirical study aims to present an overview of the current prevalence of intercropping, and its recent trends in China, using national survey dataset. The other empirical studies focus on (relay) intercropping in small-scale farming, using a case study on household decision-making in Gaotai County, Gansu Province, northwest China.Results from the first study show that intercropping was practiced on approximately three percent of the arable land in the surveyed villages, while agroforestry was practiced on approximately one percent of the arable land and one percent of the area of plantation plus forest land. The use of both these systems did not significantly change between 2009 and 2014. An explorative village-level analysis of factors associated with mixed species cultivation practices (intercropping and agroforestry) reveals a significant positive association with labour availability, and a smaller, but mostly significant, negative association with agricultural machinery power. In the case study, results reveal that technical efficiency scores are positively affected by the share of land assigned to intercropping

Plants need to defend themselves from attack by herbivorous insects. They can do this directly by producing chemical and structural defences such as toxins and spines, but also indirectly by promoting the effectiveness of enemies of the herbivores. This can be accomplished by providing resources such as nectar or shelter for these enemies, but also by providing information to the enemy on the location of their prey. These interactions form a mechanistic basis of tritrophic interactions: Interactions between plants, herbivores and enemies of these herbivores. Plants can provide natural enemies with information on herbivores by releasing chemical compounds upon damage inflicted by these herbivores. These chemical compounds are called herbivore-induced plant volatiles (HIPVs) and can be used by carnivorous animals to find their prey. Some plant species or varieties produce different HIPV blends than others, which can influence carnivore preference such as parasitic wasps or parasitoids. Parasitoids are insects that lay their eggs in or on other insects. Their offspring feed from the host insect until the parasitoid completes larval development, which usually results in the death of the host. After emerging as adults and mating, female parasitoids need to find new hosts in their environment. These hosts can be spread heterogeneously, which means the parasitoid needs to disperse to locate the hosts. While foraging for hosts, parasitoids can use HIPVs as information on the identity, quality and abundance of hosts. This process has been well characterized at small spatial scales, but little research has been done on how HIPVs attract parasitoids at larger spatial scales. The spatial distribution of HIPVs can be influenced by a range of aspects of the surrounding environment, such as weather conditions, vegetation structure and interference with chemical compounds from other plants. Little is known on how these habitat characteristics affect the foraging behaviour of parasi

The EFSA Panelon Plant Health performed a pest categorisation of Blight and blight-like' for the EU territory. Blight is a major disease of citrus. Similar blight-like' diseases are also known (e.g. declinio, declinamiento) and are addressed simultaneously with Blight in the present categorisation. The causal agent(s) remain(s) unknown and the potential role of a recently identified citrus endogenous pararetrovirus (Citrus Blight-associated pararetrovirus, CBaPRV) remains to be established. Transmissibility and ability to produce consistent (although poorly specific) symptoms have been demonstrated and a combination of indirect approaches is used, with limits, for diagnosis. There are large uncertainties on the biology of the causal agent(s) and on the epidemiology of the disease, including the transmission mechanism(s) responsible for the observed field spread. Blight has been reported from North, Central and South America, Africa and Oceania but is not known to occur in the EU. It is listed in Annex IIA of Directive 2000/29EC. It has the potential to enter, establish and spread in the EU territory. The main entry pathway (citrus plants for planting) is closed by existing legislation and entry is only possible on minor pathways (such as illegal import). Blight is a severe disease and a negative impact is expected should it be introduced in the EU, but the magnitude of this negative impact is very difficult to estimate. 'Blight and blight like' satisfies all criteria evaluated by EFSA to qualify as a Union quarantine pest. It does not meet the criterion of being present in the EU to qualify as a Union regulated non-quarantine pest (RNQP). Since the identity of the causal agent(s) of the Blight and blight-like disease(s) and the existence and efficiency of natural spread mechanism(s) remain unknown, large uncertainties affect all aspects of the present pest categorisation. (C) 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on b

1. Agriculture benefits from ecosystem services provided by mobile agents, such as biological pest control by natural enemies and pollination by bees. However, methods that can generate spatially explicit predictions and maps of these ecosystem services based on empirical data are still scarce. 2. Here we propose a generic statistical model to derive kernel functions to characterize the spatial distribution of ecosystem services provided by mobile agents. The model is similar in spirit to a generalized linear model, and uses data of landscape composition and ecosystem services assessed at target sites to estimate parameters of the kernel. The approach is tested in a simulation study and illustrated by an empirical case study on parasitism rates of the diamondback moth Plutella xylostella. 3. The simulation study shows that the scale parameter of the exponential power kernel can be estimated with limited bias, whereas estimation of the shape parameter is difficult. For the case study the model provides biologically relevant estimates for the kernel associated with parasitism of Plutella xylostella. These estimates can be used to generate ecosystem service maps for existing or planned landscapes. The case study reveals that predictions can be sensitive to the parameter values for the width and shape of the kernel, and to the link function used in the statistical model. 4. In the last two decades numerous empirical studies assessed ecosystem services at target sites and related these to the surrounding landscape. Our method can take advantage of these data by estimating underlying kernels that can be used to map the spatial distribution of ecosystem services. However, empirical data that can discriminate between alternative kernel shapes remain critical.

In an increasingly globalized world, invasive species cause major human, financial, and environmental costs. A cosmopolitan pest of great concern is the cassava mealybug Phenacoccus manihoti (Hemiptera: Pseudococcidae), which invaded Asia in 2008. Following its arrival, P. manihoti inflicted measurable yield losses and a 27% drop in aggregate cassava production in Thailand. As Thailand is a vital exporter of cassava-derived commodities to China and supplies 36% of the world's internationally-traded starch, yield shocks triggered price surges and structural changes in global starch trade. In 2009 a biological control agent was introduced in Asia-the host-specific parasitoid, Anagyrus lopezi (Hymenoptera: Encyrtidae). This parasitoid had previously controlled the cassava mealybug in Africa, and its introduction in Asia restored yield levels at a continent-wide scale. Trade network and price time-series analyses reveal how both mealybug-induced production loss and subsequent parasitoid-mediated yield recovery coincided with price fluctuations in futures and spot markets, with important cascading effects on globe-spanning trade networks of (cassava) starch and commodity substitutes. While our analyses may not imply causality, especially given the concurrent 2007-2011 food crises, our results do illuminate the important interconnections among subcomponents of the global commodity system. Our work underlines how ecologically-based tactics support resilience and safeguard primary productivity in (tropical) agro-ecosystems, which in turn help stabilize commodity markets in a similar way as pesticide-centered approaches. Yet, more importantly, (judiciously-implemented) biological control can deliver ample 'hidden' environmental and human-health benefits that are not captured by the prices of globally-traded commodities.

Chemical information influences the behaviour of many animals, thus affecting species interactions. Many animals forage for resources that are heterogeneously distributed in space and time, and have evolved foraging behaviour that utilizes information related to these resources. Herbivore-induced plant volatiles (HIPVs), emitted by plants upon herbivore attack, provide information on herbivory to various animal species, including parasitoids. Little is known about the spatial scale at which plants attract parasitoids via HIPVs under field conditions and how intraspecific variation in HIPV emission affects this spatial scale. Here, we investigated the spatial scale of parasitoid attraction to two cabbage accessions that differ in relative preference of the parasitoid Cotesia glomerata when plants were damaged by Pieris brassicae caterpillars. Parasitoids were released in a field experiment with plants at distances of up to 60 m from the release site using intervals between plants of 10 or 20 m to assess parasitism rates over time and distance. Additionally, we observed host-location behaviour of parasitoids in detail in a semi-field tent experiment with plant spacing up to 8 m. Plant accession strongly affected successful host location in field set-ups with 10 or 20 m intervals between plants. In the semi-field set-up, plant finding success by parasitoids decreased with increasing plant spacing, differed between plant accessions, and was higher for host-infested plants than for uninfested plants. We demonstrate that parasitoids can be attracted to herbivore-infested plants over large distances (10m or 20m) in the field, and that stronger plant attractiveness via HIPVs increases this distance (up to at least 20m). Our study indicates that variation in plant traits can affect attraction distance, movement patterns of parasitoids, and ultimately spatial patterns of plant-insect interactions. It is therefore important to consider plant-trait variation in HIPVs when study

The Panel on Plant Health performed a pest categorisation of the fungus Synchytrium endobioticum, the causal agent of potato wart disease, for the European Union (EU). The identity of the pest is well established and reliable methods exist for its detection and identification. S. endobioticum is present in most continents. The pest is listed in Annex IAII of Directive 2000/29/EC and is present with a restricted and fragmentary distribution in the EU. The major host is Solanum tuberosum (potato), but in Mexico, the pest also affects wild Solanum spp. S. endobioticum could potentially enter the EU through multiple pathways associated with soil as substrate for non-host plants, contaminant or commodity. The presence of the pest in 16 EU Member States characterised by different climatic conditions suggests that it could establish in the rest of the EU. The disease induces the formation of warts on potato tubers, stolons and stem bases reducing plant growth and yield and making tubers unmarketable. Additional losses may occur during storage. The only available strategy to control the disease and prevent it from spreading is the application of strict phytosanitary measures and the cultivation of potato varieties resistant to the pathotype(s) present in the infested field(s). Specific phytosanitary measures exist (Council Directive 69/464/EEC) for the control of potato wart disease in the EU. The main uncertainties refer to the distribution and host range of the pest, and the importance of some pathways of entry. S, endobioticum meets all the criteria assessed by EFSA for consideration as potential Union quarantine pest. The criteria for considering S. endobioticum as a potential Union regulated non-quarantine pest are not met since, in addition to potato seed tubers, soil (as commodity, substrate or contaminant) and ware potato tubers are major means of spread. (C) 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European

Following a request from the European Commission, the EFSA Panel on Plant Health performed a pest categorisation of Chrysomyxa arctostaphyli, a well-defined and distinguishable fungal species of the family Coleosporiaceae. The pathogen is regulated in Council Directive 2000/29/EC (Annex IAI) as a harmful organism whose introduction into the EU is banned. C. arctostaphyli is native to North America and is the causal agent of spruce broom rust. C. arctostaphyli is a heteroecious rust with a 2-year life cycle alternating between the aecial host Picea spp. and the telial host Arctostaphylos spp. The main reported aecial host is P. engelmannii, but also P. abies, P. pungens, P. sitchensis, P. glauca, P. mariana and P. rubens (as well as Picea as a genus) are reported as hosts. The fungus is not known to occur in the EU but could enter via host plants for planting and cut branches. It could establish in the EU, as hosts are present and climatic conditions are favourable. The extent of overlap between the ranges of the telial and aecial hosts is greater in the EU than in North America. The pathogen would be able to spread following establishment by dissemination of spores and human movement of infected host plants. Should the pathogen be introduced in the EU, impacts can be expected in spruce woodland, plantations and on ornamental spruce trees, leading to reduced tree growth and associated ecosystem service provision. The main uncertainty concerns the level of susceptibility of P. abies and P. sitchensis under European conditions. The criteria assessed by the Panel for consideration as a potential quarantine pest are met. As the pest is not present in the EU, not all criteria for consideration as a regulated non-quarantine pest are met. (C) 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

Following a request from the European Commission, the EFSA Panelon Plant Health performed a pest categorisation of Guignardialaricina, a well-defined and distinguishable fungal species of the family Phyllostictaceae. The pathogen is regulated in Council Directive 2000/29/EC (Annex IAI) as a harmful organism whose introduction into the EU is banned. G.laricina is native to East Asia and causes a shoot blight disease of Larix spp. Major hosts of G.laricina are European larch (Larixdecidua) and two North American larch species (Larixlaricina (tamarack) and Larixoccidentalis (Western larch)). Larixkaempferi (Japanese larch) is reported as susceptible. The only other host in nature is Douglas fir (Pseudotsugamenziesii), which is reported as an incidental host, but various other conifers have been reported as susceptible following artificial inoculation, including Piceaabies. The fungus is not known to occur in the EU but could enter via plants for planting (including artificially dwarfed plants) and cut branches of Larix spp. It could establish in the EU, as hosts are present and climatic conditions are favourable. The pathogen would be able to spread following establishment by natural dissemination of ascospores and pycnospores and by human movement of infected plants for planting. Should the pathogen be introduced in the EU, impacts can be expected in larch forests, plantations and nurseries, leading to reduced tree growth and ecosystem service provision. The key uncertainties concern the current distribution and level of impacts in the native range of the pathogen. The criteria assessed by the Panelfor consideration as a potential quarantine pest are met. As the pest is not present in the EU, not all criteria for consideration as a regulated non-quarantine pest are met. (C) 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

The Panelon Plant Health performed a pest categorisation of the non-EU Pissodes spp. (Coleoptera: Curculionidae). They constitute a well-defined taxon, with non-EU species distributed in the USA, Canada, Mexico, Guatemala, El Salvador, China, Japan, Korea, Russia and South Africa, some of which are recognised as severe pests of conifers, mainly Pinus spp. and Picea spp., or vector pathogens. The immature stages either live in the phloem and cambium of healthy, weakened or dead trees, or in the terminal shoots of living trees. They are listed as quarantine pests in Annex IAI of Directive 2000/29/EC. Plants for planting, branches of conifers and non-squared wood are considered as pathways. The pest can also disperse by hitchhiking, and fly over kilometres. The adults are long-lived (up to 4 years). They feed by puncturing the bark of stems or shoots. Females lay eggs in chewed-out cavities in the bark. The life cycle varies with species and local climatic conditions. At the end of the larval stage, the larva excavates a pupal cell between the sapwood and the bark, in the sapwood or in terminal shoots. Pissodes spp. overwinter as adults in the litter or as larvae or teneral adults in the galleries or pupal cells. The current geographic range of the non-European Pissodes spp. suggests that many of them may establish in the EU territory, where their hosts are widely present. We list some species which, if introduced to the EU, would most probably have an economic impact on plantations or may interfere with forest ecosystem processes although they are mainly abundant and damaging in intensively managed monocultures. All criteria for considering those non-EU Pissodes spp. as potential quarantine pests are met. The criteria for considering them as non-regulated quarantine pests are not met because they are absent from the EU territory. (C) 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

The Panelon Plant Health performed a pest categorisation of Grapholitapackardi Zeller, (Lepidoptera: Tortricidae), for the EU. G.packardi is a well-defined and distinguishable species. It is widely distributed in the USA and has a restricted distribution in Canada and Mexico. It is recognised as a pest of blueberry and cherry, and has occasionally been reported in apple, pear and plum. It is cited on quince and wild rosaceous plants such as Crataegus. Larvae feed on blueberry and cherry fruits internally and overwinter in pruned twigs. External evidence of infestation of cherries by young larvae is occasionally not detectable. In apple, fruit damage is less common; rather, the pest bores into terminal shoots of nursery stock and young orchard trees. Feeding damage spoils fruit quality and marketability and reduces crop yield. G.packardi is not known to occur in the EU and is listed in Annex IIAI of Council Directive 2000/29/EC under the synonym Enarmoniapackardi. Host plants for planting and infested fruit could potentially provide a pathway into the EU. Considering the climatic similarities between North America and Europe, and that wild and commercial hosts occur widely within the EU, G.packardi has the potential to establish within the EU. There would be one to three generations per year, as in North America. Based on literature, blueberries and cherries are likely to be impacted more than apples and pears. Phytosanitary measures are available to reduce the likelihood of introduction of G.packardi. All criteria assessed by EFSA for consideration as a potential Union quarantine pest are met. As G.packardi 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. (C) 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

The Panelon Plant Health performed a pest categorisation of the Siberian moth, Dendrolimussibiricus Tschetverikov (Lepidoptera: Lasiocampidae). D.sibiricus is a well-defined and distinguishable species, native to Asian Russia and northern regions of Kazakhstan, Mongolia, China and North Korea, and recognised as a severe pest of Pinaceae conifers, mainly larch (Larix spp.), fir (Abies spp.), spruce (Picea spp.), five-needle pines (Pinus spp.). It has also a potential to develop on non-native Pinaceae: Cedrus, Pseudotsuga, Tsuga. It defoliates healthy trees and kills thousands of hectares of forests. It is absent from the EU and is listed as a quarantine pest in Annex IAI of Directive 2000/29/EC. Plants for planting, branches of conifers and non-squared wood from its distribution range are considered as pathways for the pest, which can also disperse by flight over tens of kilometres. The females produce sex pheromones. Adults do not feed and can survive for about 2 weeks. One female lays up to 400 eggs, attaching them to needles. One generation usually develops in 2-3 years, with larvae passing winter diapause and some undergoing facultative summer diapause. Exceptionally, 1-year generations may occur if the number of degree-days above 10 degrees C is higher than 2,200. Larvae feed on needles through 5-6 instars and pupate in a cocoon on tree branches. Mature larvae have urticating setae on thoracic segments that protect them from enemies and may cause allergic reactions in humans and animals. The contradictory studies regarding the climatic requirements of D.sibiricus make the issue of its establishment in most of the EU territory uncertain, although its host trees are widely present. All criteria for considering D.sibiricus as a potential quarantine pest are met. The species is presently absent from the EU, and thus, the criteria for consideration as a potential regulated non-quarantine pest are not met. (C) 2018 European Food Safety Authority. EFSA Journal publishe

Following a request from the European Commission, the EFSA Panelon Plant Health performed a pestcategorisation of Coniferiporiasulphurascens and Coniferiporiaweirii, two well-defined and distinguishable fungal species of the family Hymenochaetaceae. The pathogens are regulated in Council Directive 2000/29/EC (Annex IAI, under the previous name Inonotusweirii for both species) as a harmful organism whose introduction into the EU is banned. The two pathogens are native to North America, where C.sulphurascens causes laminated root rot primarily in Douglas fir (Pseudotsuga menziesii) and grand fir (Abiesgrandis), while C.weirii causes cedar laminated root and butt rot mainly in cedars (Thujaplicata and Cupressusnootkatensis). C.weirii has been reported from Japan and China, and C.sulphurascens from China, Russia and Turkey. Neither species has been reported from the EU. C.sulphurascens may infect all conifers, while C.weirii is reported to mainly cause disease in tree species of Thuja spp. and Cupressus spp. The two pathogens could enter the EU mainly via wood with bark, isolated bark and plants for planting (including artificially dwarfed plants) of Pinaceae and Cupressaceae. Both fungi could establish in the EU, as hosts are present and climatic conditions are favourable. The two pathogens would be able to spread following establishment by the pathways mentioned for entry and also by dissemination of basidiospores and root contact with infected root/wood. Should the pathogen be introduced in the EU, impacts can be expected on coniferous woodlands, plantations and ornamental trees, thus leading to reduced tree growth and ecosystem service provision. The key uncertainties concern (i) the distribution of the two pathogens in Asia, (ii) the level of susceptibility of conifers native to Europe and (iii) the role of plants for planting as a pathway of entry and spread. For both pathogens, the criteria assessed by the Panelfor consideration as a potential quarantine pest are

The Panelon 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 (Hirschmanniellabehningi, Hirschmanniellagracilis, Hirschmanniellahalophila, Hirschmanniellaloofi and Hirschmanniellazostericola). The whole genus except H.gracilis is regulated by Council Directive2000/29/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 rega

The Panelon Plant Health performed a pest categorisation of Colletotrichumgossypii, the fungal agent of anthracnose and ramulosis diseases of cotton, for the EU. The identity of the pest is well established and reliable methods exist for its detection/identification. The pest is present in most of the cotton-growing areas worldwide, including Bulgaria and Romania in the EU. Colletotrichumgossypii is listed as Glomerellagossypii in Annex IIB of Directive 2000/29/EC and is not known to occur in Greece, which is a protected zone (PZ). The only hosts are Gossypium species, with G.hirsutum and G.barbadense being the most susceptible. The pest could potentially enter the PZ on cotton seeds originating in infested third countries or EU infested areas. Entry into PZ by natural means from EU infested areas is possible, although there is uncertainty on the maximum distance the pest can travel by wind or insects. Bolls and unginned cotton are minor pathways of entry. Pest distribution and climate matching suggest that the pest could establish and spread in cotton-producing areas of northern Greece. In the infested areas, the pest causes damping-off, leaf/boll spotting, boll rot, witches' broom symptoms and stunting resulting in yield and quality losses. It affects also the lint and seeds reducing fibres quality and seed germinability. It is expected that its introduction and spread in the EU PZ would impact cotton yield and quality. The agricultural practices and control methods currently applied in Greece would not prevent pest establishment and spread. Colletotrichumgossypii meets all the criteria assessed by EFSA for consideration as potential quarantine pest for the EU PZ of Greece. The criteria for considering C.gossypii as a potential Union regulated non-quarantine pest are also met since cotton seeds are the main means of spread. (C) 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.

The Panel on Plant Health performed a pest categorisation of Xiphinema americanum sensu lato (Nematoda: Longidoridae) for the EU. Sixty-one species in this group are recognised. They are polyphagous pests found in soil associated with a number of plant species. As a migratory ectoparasitic species, it punctures cells of plant roots. Nematodes were classified in four categories based on their distribution and ability to transmit viruses. Category I contains the seven virus vector species present outside the EU: X. americanum sensu stricto, X. bricolense, X. californicum, X. inaequale, X. intermedium, X. rivesi (non-EU populations) and X. tarjanense. Category II contains the 28 species not present in the EU and not known to transmit any virus. Twenty-six species are present in the EU and are not known to be virus vectors (category III). Category IV contains the species present in the EU, which is a virus vector (EU populations of X. rivesi). All nematodes known to be virus vectors occurring outside the EU (category I) satisfy all the criteria that are within the remit of EFSA to assess to be regarded as Union quarantine pests. This is mainly due to their association with non-EU virus isolates. Categories II and III contain species that are not reported to transmit viruses or cause economic damage to crop plants. Although uncertainty concerning their ability to transmit viruses exists, those species do not satisfy all the criteria to be regarded as Union quarantine pests. Category IV contains the EU populations of X. rivesi. The species is a virus vector but current EU populations of X. rivesi have not been reported to be associated with any of the EU viruses or their non-EU isolates under field conditions. Xiphinema rivesi (EU populations) is widespread in some Member States and does not satisfy all the criteria to be regarded as a Union quarantine. None of the species can be regarded as a regulated non-quarantine pest. (C) 2018 European Food Safety Authority. EFSA Jo

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 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. (c) 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons L

The Panel on Plant Health performed a pest categorisation of the fungus Thecaphora solani, the causal agent of smut of potato, for the EU. The identity of the pest is well established and reliable methods exist for its detection and identification. T solani is present in Bolivia, Chile, Colombia, Ecuador, Mexico, Panama, Peru and Venezuela. The pathogen is not known to occur in the EU and is listed in Annex IAI of Directive 2000/29/EC, meaning its introduction into the EU is prohibited. The major host is Solanum tuberosum (potato), but various other tuber-forming Solanum species are also affected. The pest has also been reported on Solanum lycopersicum (tomato), and wild solanaceous plants are also affected. All the major hosts and pathways of entry are currently regulated. Host availability and climate matching suggest that T solani could establish in parts of the EU and further spread by human-assisted means. The disease induces gall formation on potato tubers, stolons and underground stem parts, reducing yield and making tubers unmarketable. The pest introduction in the EU would potentially cause impacts to potato production. In the infested areas, the only available strategy to control the disease and prevent it from spreading is the application of quarantine and sanitation measures and the cultivation of resistant varieties. The main uncertainties concern the host range, the biology and epidemiology of the pest, and the potential of the pest to enter the EU through three unregulated minor pathways. T solani meets all the criteria assessed by EFSA for consideration as potential Union quarantine pest. The criteria for considering T solani as a potential Union regulated non-quarantine pest are not met, since the pest is not known to occur in the EU. (C) 2018 European Food Safety Authority. EFSA Journal published by John Wiley and Sons Ltd on behalf of European Food Safety Authority.