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Commercial tomatoes are usually complex F1 hybrids with multiple resistances genes 9 from different wild Solanum species. The response of tomato cultivars with resistance to root-knot 10 nematodes (RKN) and Tomato yellow leaf curl virus (TYLCV) to infection by M. javanica was deter- 11 mined in controlled environment and in the field. Four treatments were tested: cultivars with i) 12 RKN resistance alone, ii) RKN and TYLCV resistance (RKN+TYLCV), iii) TYLCV resistance alone, 13 and iv) none (susceptible to the nematode and virus). The RKN resistant plants were highly effective 14 suppressing nematode infection and reproduction both in controlled environment and in the field. 15 The RKN+TYLCV resistant plants were also effective but less (P

Background and Aims Intercropping of truffle-producing trees with aromatic plants is used to improve profitability of truffle orchards during the initial 4–7 years. However, after that period the viability of this system is challenged by the appearance of brûlés, an area around host tree characterised by scarce plant cover where the fungus exhibits allelopathic activity. We aimed to investigate the ecological interactions between these crops and between their associated mycorrhizal fungi in adult truffle plantations. Methods We simulated two intercropping systems, truffle oak – lavender and truffle oak – rosemary in their adult stage. We analysed and compared aromatic plants and soil samples inside and outside the brûlés during the first year of the aromatic plants in the field. Results We found a strong negative relation of brûlés with the growth of the aromatic plants, although not a decrease in the arbuscular mycorrhizal colonization of their roots. The essential oil yield and composition of aromatic plants was affected by brûlés. The extraradical truffle mycelium was not significantly affected by the presence of aromatic plants. Conclusions The growth and yield of aromatic plants was impaired during their first year growing in brûlés, whereas no negative effect of aromatic plants on truffle fruiting potential was found. The study improves our understanding of the mechanisms influencing the viability of the truffle tree – aromatic plant intercropping and the possible technical challenges. info:eu-repo/semantics/acceptedVersion

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Twenty-five almond cultivars were assessed for susceptibility to Diaporthe amygdali, causal agent of twig canker and shoot blight disease. In laboratory experiments, growing twigs were inoculated with four D. amygdali isolates. Moreover, growing shoots of almond cultivars grafted onto INRA ‘GF-677’ rootstock were used in 4-year field inoculations with one D. amygdali isolate. In both types of experiments, inoculum consisted of agar plugs with mycelium, which were inserted underneath the bark, and the lesion lengths caused by the fungus were measured. Necrotic lesions were observed in the inoculated almond cultivars in both laboratory and field tests, confirming the susceptibility of all evaluated cultivars to all inoculated isolates of D. amygdali. Cultivars were grouped as susceptible or very susceptible according to a cluster analysis. The relationship between some agronomic traits and cultivar susceptibility was also investigated. Blooming and ripening times were found to be relevant variables explaining cultivar performance related to D. amygdali susceptibility. Late and very late blooming and early and medium ripening cultivars were highly susceptible to D. amygdali. Our results may provide valuable information that could assist in ongoing breeding programs of this crop and in the selection of cultivars for new almond plantations. info:eu-repo/semantics/acceptedVersion

The high value of black truffle recompenses the slow growth of the fungus when established in the field. Adding a secondary crop, such as medicinal and aromatic plants (MAPs), could further enhance the sustainability of truffle production agro-forest systems. The dual cultures of ectomycorrhizal truffle-oak seedlings and MAPs (lavender, thyme, and sage) previously inoculated and non-inoculated with native arbuscular mycorrhizal fungi (AMF), were established to evaluate plant–fungi relationships. After 12 months in a shadehouse, plants’ growth, mycorrhizal colonization, and extraradical soil mycelium (both of Tuber melanosporum and AMF) were measured. Overall, truffle-oaks’ growth was negatively affected by the presence of MAPs, especially when inoculated with AMF. In turn, the presence of truffle-oaks barely affected the co-cultured MAPs, and only lavenders showed a significant growth reduction. All AMF-inoculated MAPs showed higher shoot and root biomass than non-inoculated ones. Compared to truffle-oaks growing alone, the presence of co-cultured MAPs, especially when they were AMF-inoculated, significantly decreased both the ectomycorrhizas and soil mycelium of T. melanosporum. These results reveal the strong competition between AMF and T. melanosporum and warn about the need for the protection of intercropping plants and their associated symbiotic fungi to avoid reciprocal counterproductive effects in mixed truffle-oak–AMF–MAP plantations.

Tuta absoluta is one of the largest threats to tomato agriculture worldwide. Native to South America, it has rapidly spread throughout Europe, Africa, and Asia over the past two decades. To understand how T. absoluta has been so successful and to improve containment strategies, high-quality genomic resources and an understanding of population history are critical. Here, we describe a highly contiguous annotated genome assembly, as well as a genome-wide population analysis of samples collected across Latin America. The new genome assembly has an L50 of 17 with only 132 contigs. Based on hundreds of thousands of single nucleotide polymorphisms, we detect three major population clusters in Latin America with some evidence of admixture along the Andes Mountain range. Based on coalescent simulations, we find these clusters diverged from each other tens of thousands of generations ago prior to domestication of tomatoes. We further identify several genomic loci with patterns consistent with positive selection and that are related to insecticide resistance, immunity, and metabolism. This data will further future research toward genetic control strategies and inform future containment policies.

Rice is an important cereal crop in Spain that is frequently attacked by pests that cause significant quantitative and qualitative losses. Among them, the maize weevil, Sitophilus zeamais, is the key pest, and the lesser grain borer, Rhyzopertha dominica, is a serious pest found later in the season. The cosmopolitan ectoparasitoid, Anisopteromalus calandrae, which attacks late-instar larvae of coleopterans that develop inside grain kernels, has been reported as an efficient natural enemy. In this study, we evaluated whether the control efficacy of this parasitoid on S. zeamais was affected by the presence of the alternative host, R. dominica. Our laboratory experiment demonstrated the parasitoid preference for S. zeamais larvae when mixed with R. dominica larvae at different proportions. This preference for the maize weevil larvae allowed us to maintain a similar control efficacy of S. zeamais when it was offered alone than when it was offered together with R. dominica larvae. In our second experiment, done in 500 kg bags of paddy rice, similar results were obtained, since the presence of R. dominica larvae did not alter the control efficacy of A. calandrae on S. zeamais larvae. Therefore, our results confirmed a good perspective for implementing the use of this natural enemy as a control tool in big bags of paddy rice info:eu-repo/semantics/publishedVersion

The resistance of the citrus rootstock Forner-Alcaide 5 to Tylenchulus semipenetrans was assessed in comparison to the susceptible Carrizo citrange (S) in two replant situations. Changes in soil and root population densities were monitored after planting the new trees to detect tree infection and nematode population growth over time. The efficacy of pre-plant control methods such as fumigation with 1,3 Dichloropropene (1,3D) or 2-year fallowing was also assessed. Fumigation and fallowing reduced juveniles + males/250 cm3 soil to undetectable levels for 3 and 2 years, respectively, and postponed root parasitism on Forner-Alcaide 5 for 3 and 2.5 years, respectively. Forner-Alcaide 5 supported lower densities of juveniles + males/250 cm3 soil and females/g root than Carrizo citrange in both replant situations The efficacy of the resistant rootstock was enhanced when combined with 1,3D fumigation or 2-year fallowing because the pre-planting control reduced densities of juveniles + males in soil before establishing the orchard, and the resistant rootstock, the female densities in the roots his work was supported by Instituto Nacional de Investigación Agraria y Alimentaria (INIA) of Spain (grants SC98-103-C2; RTA02-068 and RTA05-00086-00-00) and European Funds for Regional Develop- ment (FEDER). We acknowledge Dr. J. B. Forner, who passed away while we were preparing the manuscript, for providing the rootstocks used in the study. The assistance of A. Alcaide in the field experiments and Dr. A. Catena in the statistical analyses is greatly appreciated. Thanks are also given to Miguel Fabregat (in memoriam) and Maria Carmen Fabregat for allowing conducting experiment 1 at their prop- erty.

Ground-cover vegetation attracts and harbors beneficial insects to the agrosystem, playing an important role in conservation biological control. Integrated pest management (IPM) program guidelines recommend the implantation of sowed or resident wild covers in perennial crops. Given the high-quality fruit requirements, even in IPM programs, insecticides can be required in citrus crops. This study presents, over a year, the levels of neonicotinoids (thiamethoxam and imidacloprid) in not-target ground-cover wildflowers growing spontaneously in citrus orchards after foliar treatment of citrus trees. The presence and persistence of these neonicotinoids in different wildflower species were studied. Concentrations of thiamethoxam and imidacloprid in whole wildflowers ranged from −1 and from −1, respectively. Thiamethoxam was more frequently detected than imidacloprid. Thiamethoxam and imidacloprid were detected up to 336 and 230 days after treatment, respectively. The highest detection frequencies (100%) and highest thiamethoxam and imidacloprid mean concentrations (26.0 ± 7.3 ng g−1 and 11.0 ± 10.6 ng g−1, respectively) occurred in wildflowers collected 9 days after the treatments. Since application, a clear decrease in the concentration of both compounds and differences in the accumulation depending on wildflower species were observed. Cross contamination was detected, indicating a transport from adjacent treated plots. Maintaining a cover crop in citrus orchards may lead to detrimental effects on non-target arthropods if these neonicotinoid compounds are used for pest control since they can entail a chronic exposure during at least 230 days for imidacloprid and 336 days for thiamethoxam.

Altres ajuts: CERCA Program, Generalitat de Catalunya The dynamics of airborne ascospores and disease progress of red leaf blotch (RLB) of almond, caused by Polystigma amygdalinum, and their correlations with weather variables were studied from 2019 to 2021 in two almond orchards located in Lleida, NE Spain. Airborne ascospores were detected and quantified by real-time qPCR using species-specific primers for P. amygdalinum. Ascospores were detected mainly from April to June, with a high variability between the yearly cumulative concentrations. Positive significant correlations were found between the weekly proportion of airborne ascospores and the number of wet and mild days-either combined or separated- accumulated rainfall, number of rainy days, accumulated low temperatures on wet days, and mean and maximum relative humidity. In contrast, several thermal variables (maximum temperature, VPD, and number of warm days) were negatively correlated with ascospore catches. Positive significant correlations were found between the cumulative proportion of ascospores and RLB incidence and severity. Weekly variations in RLB incidence and severity showed significant positive correlations with the number of warm days while negative with the number of mild days. Severity was also positively correlated with several thermal variables (mean, maximum, and minimum temperature, and VPD), and negatively correlated with the number of cold days and wet and mild days. Stronger correlations were generally found with ascospore catches or disease progress when using concurrent weekly weather data. Gompertz, monomolecular, and logistic growth models were evaluated to describe RLB disease progress.

The increase in energy and fertilizer consumption makes it necessary to develop sustainable alternatives for agriculture. Anaerobic digestion and digestates appeared to be suitable options. However, untreated digestates still have high water content and can increase greenhouse gas emissions during storage and land application. In this study, manure-derived digestate and solid fraction of digestate after separation were treated with a novel solar drying technology to reduce their water content, combined with acidification to reduce the gaseous emissions. The acidified digestate and acidified solid fraction of digestate recovered more nitrogen and ammonia nitrogen than their respective non-acidified products (1.5–1.3 times for TN; 14 times for TAN). Ammonia and methane emissions were reduced up to 94% and 72% respectively, compared to the non-acidified ones, while N2O increased more than 3 times. Dried digestate and dried acidified digestate can be labeled as NPK organic fertilizer regarding the European regulation, and the dried solid fraction and the improved dried acidified solid fraction can be labeled as N or P organic fertilizer. Moreover, plant tests showed that N concentrations in fresh lettuce leaves were within the EU limit with all products in all the cases. However, zinc concentration appeared to be a limitation in some of the products as their concentration exceeded the European legal limits. This work was funded by the European Union under the Circular Agronomics project (H2020 research and innovation project Nº.773649) and Nutry2Cycle project (H2020 research and innovation project Nº.773682). IRTA thanks the support of the CERCA Program and the Consolidated Research Group TERRA (ref.2017SGR1292), both from the Generalitat de Catalunya. L. Morey thanks the financial support of AGAUR, of the Generalitat de Catalunya (grant reference number 2019FI_B00694). We would like to thank the help of Celia Segura Godoy and Pau Berenguer i Planas during the sampling campaigns.

Polarimetric techniques are widely used in a vast number of applications such as remote sensing, material characterization, astronomy and biological tissue inspection. In this last scenario, different polarimetric observables have proved their potential for enhancing imaging visualization. In this work we use a set of polarimetric observables derived from the arrow decomposition of the Mueller matrix for the first time: enpolarizing, retarding and depolarizing descriptors. In particular, the mean intensity coefficient and the three indices of polarimetric purity, the absolute values and Poincaré orientations of diattenuation, polarizance, entrance retardance and exit retardance vectors are considered. Results show images with enhanced visualization or even revealing invisible structures when compared to standard intensity images. In particular, thanks to these metrics, we improve the visualization of the necrotic areas of a Vitis rupestris leaf. In the case of animal samples, boundaries between different fascicles inside a tendon of an ex vivo chicken sample are revealed, as is the directionality of fiber tracts of the subcortical white matter in an ex vivo cow brain. The experimental results show the potential for biophotonics imaging and how polarimetric techniques could be useful for biomedical and botanical applications. info:eu-repo/semantics/publishedVersion

Phosphorus and nitrogen recovery from wastewater as struvite and ammonium nitrate (AN) may be viable alternative fertilizers to boost circularity in horticulture. A 2-year fertigated crop rotation in soil under greenhouse conditions was evaluated to determine the efficiency of both recovered products as raw materials for a nutrient solution (NS) manufacture. The effects of these treatments versus synthetic fertilizers were compared in terms of crop performance, plant nutrient uptake, soil chemistry and microbiota. This is the first study to implement struvite through fertigation as the sole source of P in soil crops. Results showed that both recovered products can be used as fertilizers in NS, due to the similar response to the control for different parameters and crops (tomato, lettuce, and cauliflower). However, the AN treatment showed lower yield in the first tomato crop, which results may depend on the cultivar ammonium tolerance. Besides, the concentration of heavy metals in fruits/leaves was below the permissible limits. Total and Olsen phosphorus soil analysis revealed no differences among treatments, resulting in a similar performance of P-struvite to commercial phosphate. Bulk soil bacteria structure, richness and relative dominance were increased over time, while archaea only showed lower evenness, both despite the fertilization strategy. Shannon diversity was not significantly affected. A predominance of ammonia-oxidizing bacteria (AOB) versus archaea (AOA) was observed, while nitrite-oxidizing bacteria (NOB), dominated by Nitrospira, increased with fertigation. Our results demonstrate that fertilizer blends for NS containing recovered nutrients are a feasible alternative to synthetic fertilizers. info:eu-repo/semantics/acceptedVersion

BACKGROUND Combining different biocontrol agents, particularly micro- and macroorganisms, can contribute to new and sustainable pest control approaches. Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most destructive pests of solanaceous crops. An emerging management strategy consists of biological control using microbial insecticides such as baculoviruses, but with limited efficacy. Thanks to their high target specificity, baculoviruses can be used simultaneously with natural enemies such as parasitoids for improved control of T. absoluta. However, potential indirect nontarget effects of baculoviruses on parasitoids can result from overlapping resource requirements. We assessed whether ovipositing parasitoid females discriminated against virus-treated hosts and examined the outcome of within-host competition between the hymenopteran parasitoids Necremnus tutae (Reuter) (Eulophidae) and Dolichogenidea gelechiidivoris Marsch (Braconidae), and the Phthorimaea operculella granulovirus (PhopGV, Baculoviridae) that infects T. absoluta larvae. RESULTS Female D. gelechiidivoris discriminated against virus-treated hosts, whereas N. tutae did not. We found few indirect virus-related effects depending on the species, the sex, and the time of virus treatment. Effects were ambivalent for D. gelechiidivoris offspring and ranged from increased male longevity when infection occurred before parasitization to reduced emergence and male longevity when infection occurred after parasitization. N. tutae offspring showed a longer development time and shorter male longevity when they developed in virus-treated hosts. CONCLUSION The virus had a low impact on parasitoid offspring. In rare cases, adverse effects were detected; however, the low magnitude of these effects is unlikely to reduce the fitness of parasitoid offspring, therefore both parasitoids seem compatible with the baculovirus for control of T. absoluta. info:eu-repo/semantics/acceptedVersion

Waste management of brewery by-products is economically and environmentally problematic. In the frame of bio-recycling, this study aims to investigate the bioconversion of brewery by-products by filamentous fungi. Pleurotus ostreatus and Lentinula edodes were grown on different substrates based on brewer’s spent grains (fresh and dry). Afterwards, fatty acids and sterols were determined. Following the selection of the suitable substrate composition for fungal growth, results showed that fatty acids composition of fungal biomasses varied significantly as a function of substrate and fungal strain. Interestingly, fungal fat might be used for human nutrition due to low SFA/UFA ratios (~0.2–0.4) within the same range of vegetal oils. Sterols profile of fungi biomass revealed the predominance of ergosterol. Also, it was found that the fungi growing on by-products slightly reduced the cholesterol contents. As such, this approach focusing on the bioconversion of by-products using fungi can provide biomasses with a fat composition suitable for feed and human consumption. info:eu-repo/semantics/publishedVersion

The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), has invaded most Afro-Eurasian countries and is threatening worldwide tomato production. Various strategies have been developed and implemented to manage this pest. Here, we present a timely review on the up-to-date development and practical implementation of integrated pest management (IPM) programs for tomato crops across different world regions infested by T. absoluta. While insecticide resistance is a growing concern, biological control via releasing or conserving arthropod natural enemies and sex pheromone-based biotechnical control are the most successful management practices. Agronomic control-related research is an emerging area where the soil fertilization and/or irrigation, as well as breeding of resistant cultivars, has the potential to enhance IPM effectiveness. Grower survey responses in the native areas (i.e., South America), early-invaded areas (i.e., first report between 2006 and 2012) and newly invaded areas (i.e., first report after 2012) showed that the control programs evolved along with the areas and time since invasion. Growers in the early-invaded areas shifted more rapidly from chemical control to biological control compared to those from the native area. In all concerned regions, the pest control failure risk following chemical insecticide applications and the high cost associated with either biological or biotechnical control methods have been the greatest concerns for growers. The information gathered from the native and/or early-invaded areas may help achieve a more effective management in newly invaded areas. Lastly, researchers are expected to break the bottlenecks of some key issues that would enable lowering application cost of novel biorational alternative management options.

Aphis frangulae (Hemiptera: Aphididae) is a major pest of the laurel forest endemic Frangula azorica (Rosales: Rhamnaceae) produced in nursery conditions by the Forestry Services of the Azores (Portugal). The suitability of A. frangulae for the development and reproduction of a potential biological control agent, Scymnus nubilus (Coleoptera: Coccinellidae), was assessed under laboratory conditions (25 ± 1 °C, 75 ± 5% RH, 16:8 L:D photoperiod). The predation potential of S. nubilus was also assessed. Scymnus nubilus 4th instar larvae and pupae successfully completed development in 9.0 ± 0.2 days. The 4th instar larvae ate 15.1 aphids per day, corresponding to 1.52 mg of biomass ingested. On A. frangulae, S. nubilus females took 5.5 ± 0.3 days to start oviposition and an average of 135 ± 12 eggs were laid per female over the first 15 days of oviposition. Field tests showed that S. nubilus 4th instar larvae were more efficient in controlling the pest in closed systems (isolated aphid colonies) and the effect was more pronounced at high predator densities within three days. In open systems, the aphid natural control was higher than initially expected. This work highlights the role of the large aphidophagous guild present in forestry nurseries. The results of this study show that A. frangulae is an essential prey species for S. nubilus and therefore the predator can be used in pest management programs against this pest. However, further studies focusing on different biological control tactics (inundative or inoculative) are required to assess more accurately the effectiveness of S. nubilus as a biological control agent against A. frangulae. This research was supported by the Official Forestry Services from the Regional Government of the Azores, through the research project PICA 'Utilização de agentes de controlo biológico para o combate a populações de afídeos em plantas endémicas produzidas em viveiro', and PICONNIA "Controlo biológico de populações de pragas de plantas endémicas produzidas em viveiro", in direct collaboration with the Forestry Engineers Carina Nóbrega and Catarina Quintela. info:eu-repo/semantics/publishedVersion

International audience; The black truffle Tuber melanosporum was disseminated all over the world, propelled by the development of a wide variety of empirical practices. A widespread practice, called ‘truffle trap’, consists of placing pieces of truffles into excavations dug under host trees, and of collecting truffle in these traps in the next years. This research aims at (1) evaluating the effect of this practice on fruitbody production based on the analysis of 9924 truffle traps installed in 11 orchards across T. melanosporum native area in France and (2) exploring the mechanisms involved in fruitbody emergence using traps where the genotypes of introduced truffles were compared with those of fruitbodies collected in the same traps. We confirmed that truffle traps provide a major and highly variable part of truffle ground production, representing up to 89% of the collected fruitbodies. We evidenced a genetic link between introduced spores and collected fruitbodies, and then demonstrated that truffle growers provide paternal partners for mating with local maternal mycelia. We also highlighted that soil disturbance stimulate the vegetative development of established maternal mycelia. This research supports that a widely used traditional practice enhances fruitbody production by shaping favorable conditions and providing sexual partners required for fruiting.The black truffle Tuber melanosporum was disseminated all over the world, propelled by the development of a wide variety of empirical practices. A widespread practice, called ‘truffle trap’, consists of placing pieces of truffles into excavations dug under host trees, and of collecting truffle in these traps in the next years. This research aims at (1) evaluating the effect of this practice on fruitbody production based on the analysis of 9924 truffle traps installed in 11 orchards across T. melanosporum native area in France and (2) exploring the mechanisms involved in fruitbody emergence using traps where the genotypes of introduced truffles were compared with those of fruitbodies collected in the same traps. We confirmed that truffle traps provide a major and highly variable part of truffle ground production, representing up to 89% of the collected fruitbodies. We evidenced a genetic link between introduced spores and collected fruitbodies, and then demonstrated that truffle growers provide paternal partners for mating with local maternal mycelia. We also highlighted that soil disturbance stimulate the vegetative development of established maternal mycelia. This research supports that a widely used traditional practice enhances fruitbody production by shaping favorable conditions and providing sexual partners required for fruiting.

Agricultural intensification is affecting the biological control of insect pests, an important component for sustainable crop production. To understand the changing patterns of insect abundance within an agroecosystem, it is necessary to disentangle the trophic interactions between species, and metabarcoding is an excellent alternative to show them. In the Ebro Basin (NE Iberian Peninsula), agricultural landscapes are composed of a mosaic of crops scattered with natural and semi-natural habitats, where the presence of Orius spp., used as biocontrol agents, is well known. To shed light on their predatory role in this area, a previously developed metabarcoding multi-primer method has been used to study the arthropod and plant most frequently resources consumed by some field-collected Orius, sampled at different dates in a peach and an alfalfa adjacent crop. Their high-throughput sequencing (HTS) analysis showed the consumption of 15 arthropod and 12 plant taxa. Eight of them were consumed by O. laevigatus, six by O. majusculus and 23 by O. niger. The obtained results showed that HTS is a powerful tool in studies of trophic interactions in agroecosystems. Among the detected arthropods, other natural enemies were present, showing a certain degree of intraguild predation, which has been demonstrated by developing a new added strategy in the bioinformatic analysis. Detected plant consumption indicates that Orius forages on several plant species, showing their movement from them to the sampled crops. These plants could have a potential role in attracting or maintaining these predators in both crops in biological control strategies.

We assess the effects of changing land use and crop management on alfalfa insect abundance by comparing it in 50 alfalfa fields when they were inserted in landscapes with different proportions of arable crops and orchards. Land use in a buffer of 500m.was assessed and alfalfa insect abundance was estimated with sticky yellow traps.Numbers of catches of several herbivores and predators were related to the proportion of landscape components and several field variables. Results indicated that the proportion of orchards in the buffer negatively affected the abundance of predators on alfalfa; likely because orchards treated with pesticides are a sink for predators moving in the landscape, among other possible causes. Other landscape variables such as noncrop habitats, winter cereals, and landscape diversity analyzed by the Shannon index had a minor influence. Among field variables, field size influenced positively the abundance of insects on alfalfa whereas alfalfa growth stage and age affected positively or negatively the different herbivores and predators. Of course, abundance of predators and prey was affected by the abundance of prey and predators, respectively. These findings suggest that a high proportion of intensively managed crops (orchards) in the landscape interferes with the role of alfalfa as a reservoir of predatory insects for adjacent crops and that the responses to local and landscape structures are temporal and species-specific as previously concluded for maize. Consequently, landscape and field management strategies to improve pest control must consider both types of variables as well as their changing influence when we modify them. info:eu-repo/semantics/acceptedVersion

Global warming affects the distribution of stored product pest insects across Europe in a way comparable to field crop and orchard pests. Nevertheless, stored product research has been neglected in Europe and detailed monitoring is lacking. This paper aims to illustrate current knowledge about the movement of storage pests up north today triggered by altered environmental conditions. In addition, it stresses the need for a pan-European surveillance to monitor the distribution, movement and spreading of stored product pests in a rapidly changing environment. Global warming and a growing number of extreme weather conditions may influence on climate and can negatively affect global food security, especially in the case of durable commodities, which are of fundamental importance for human nutrition. It is thus suggested that the distribution of stored product pests within Europe is uniformly monitored and studied by a joint initiative. Furthermore, for additional food safety the World Food Program should receive more support to fund research needed and provide larger food storages in regions prone to agricultural instability. It is also suggested that the missing quarantine/regulated status for the most serious stored product and invasive pests (such as Trogoderma granarium) should be re-evaluated in the EU. info:eu-repo/semantics/acceptedVersion

Various pest species cause significant damage to stored rice, and polyphagous parasitoids could offer an appropriate biological control strategy. Among the beneficial species colonising silos and warehouses of rice, the generalist pteromalid parasitoids Anisopteromalus calandrae and Lariophagus distinguendus have been found to be prevalent in samples collected in the northeast of Spain. In this study, the Spanish strains of both parasitoids have shown that they may play important roles in controlling three coleopteran pests of stored rice: Sitophilus oryzae, Rhyzopertha dominica and Lasioderma serricorne. They reduced the number of pests that emerged due to effective parasitism (parasitoids reaching the adult stage and emerging from the grain), combined with other sources of host mortality, such as parasitoid immature mortality and parasitoid host feeding. Both parasitoids preferentially attack S. oryzae, which is a key pest of stored rice, but they also play an important role in the control of R. dominica, a less important pest. Although both parasitoids could consume L. serricorne larvae, their efficacy is low, and more specific natural enemies should be evaluated for the control of this pest info:eu-repo/semantics/publishedVersion

About 13% and 7% of monitored groundwater stations in Europe exceed the permitted levels of nitrates (50 mg NO3- L-1) or pesticides (0.1 μg L-1), respectively. Although slow sand filtration can remove nitrates via denitrification when oxygen is limited, it requires an organic carbon source. The present study evaluates the performance of the use of wood pellets and granulated cork as carbon sources in bench-scale biofilters operated under water-saturated and water-unsaturated conditions for more than 400 days. The biofilters were monitored for nitrate (200 mg L-1) and pesticide (mecoprop, diuron, atrazine, and bromacil, each at a concentration of 5 μg L-1) attenuation, as well as for the formation of nitrite and pesticide transformation products. Microbiological characterization of each biofilter was also performed. The water-saturated wood biofilter achieved the best nitrate removal (>99%), while the cork biofilters lost all denitrification power over time (from 38% to no removal). The unsaturated biofilter columns were not effective for removing nitrates (20-30% removal). As for pesticides, all the biofilters achieved high removal rates of mecoprop and diuron (>99% and >75%, respectively). Atrazine removal was better in the wood-pellet biofilters than the cork ones (68-96% vs. 31-38%). Bromacil was only removed in the water-unsaturated cork biofilter (67%). However, a bromacil transformation product was formed there. The water-saturated wood biofilter contained the highest number of denitrifying microorganisms, with Methyloversatilis as the characteristic genus. Microbial composition could explain the high removal of pesticides and nitrates achieved in the wood-pellet biofilter. Overall, the results indicate that wood-pellet biofilters operated under water-saturated conditions are a good solution for treating groundwater contaminated with nitrates and pesticides., The authors are grateful for the financial support of the European Union through the project LIFE18 ENV/ES/000199 and the Catalan DemoProject Democleanleach, CENTRE CERCA. ME acknowledges the funding received through the Beatriu de Pinós 2018 grant program (MSCA grant agreement number 801370). IDAEA-CSIC is a Severo Ochoa Center of Excellence (Spanish Ministry of Science and Innovation, Project CEX2018-000794-S). Finally, the authors wish to thank Yolanda Rodríguez and Albert Menéndez for their valuable help in the sampling process and chemical sample analysis and Yolanda Lucas for her technical assistance with the molecular biology analyses performed at the IRTA (Spain).

Conservation biological control could be an alternative to insecticides for the management of the aphid Myzus persicae (Sulzer). To develop sustainable strategies for M. persicae control in peach orchards in the Mediterranean, a 2-yr field experiment was conducted to identify the key predators of the aphid; to determine whether the proximity of insectary plants boost natural enemies of M. persicae in comparison to the resident vegetation; and whether selected insectary plants enhance natural enemy populations in the margins of peach orchards. Aphidoletes aphidimyza Rondani (Diptera: Cecidomyiidae) and Episyrphus balteatus De Geer (Diptera: Syrphidae) were the most abundant predators found among sentinel aphid colonies, accounting for 57% and 26%, respectively. Samplings during 2015 yielded twice as many hoverflies in M. persicae sentinel plants close to the insectary plants as those close to the resident vegetation. The abundance of other natural enemies in sentinel plants, depending on their proximity to the insectary plants, was not significantly different in either of the 2 yr. Hoverflies hovered more often over the insectary plants than over the resident vegetation and landed significantly more often on Lobularia maritima (L.) Desv., Moricandia arvensis (L.) DC., and Sinapis alba L. (Brassicales: Brassicaceae) than on Achillea millefollium L. (Asterales: Compositae). Parasitoids were significantly more abundant in L. maritima and A. millefollium. The vicinity of selected insectary plants to peach orchards could improve the presence of hoverflies, which might benefit the biological control of M. persicae.

Aquest recurs no està disponible en accés obert per política de l’editorial. This item isn't open access because of publisher's policy The presence of weevils is a concerning problem surrounding stored rice that is not well controlled with available pesticides, and alternative solutions are demanded nowadays by industry. The introduction of natural enemies can be very effective in closed environments where the grain is stored. In this study, we evaluated the effectiveness of the larval parasitoid, Anisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae), in reducing the populations of two problematic internal feeders of rice, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae) and Sitophilus zeamais (Motschulsky) (Coleoptera: Curculionidae). Three parasitoid:host ratios (1:1, 2:1, 4:1) were tested in small containers with 2Kg of brown rice at 23 and 28ºC during two host generations. Afterwards, host and parasitoid emergence, and rice damage was evaluated. The parasitoid drastically reduced both pest numbers (up to 99% reduction compared with the control treatment without the parasitoid) and their associated damage to rice grains (insect-damaged kernels, frass production and mould presence). The parasitoid was very effective at 23 and 28ºC over S. zeamais and at 28ºC over R. dominica at all parasitoid:host ratios tested. In conclusion, the introduction of A. calandrae could avoid the development of abundant populations of R. dominica and S. zeamais, representing a good control alternative to be further developed for the containment of the two pests in stored rice info:eu-repo/semantics/publishedVersion

Using chemical insecticides in IPM is possible and could be sustainable. To find a sustainable alternative to control S. impressella, we assessed the biological activities of five commercial formulations of Bacillus thuringiensis. First, these formulations were evaluated under laboratory conditions. No differences were observed between the commercial formulations Bt_A_1, BT_K_2, and Bt_K_3. Then, the three formulations were compared in further experiments. This bioassay was performed under field conditions in palms naturally infested by S. impressella, and differences in larval mortality rates were observed between commercial formulations. The mortality rates caused by Bt_A_1 and BT_K_3 did not significantly differ. The third step evaluated different doses of Bt_A_1 and BT_K_3 formulations (250, 500, 750, and 1000 g/Ha) under field conditions. Seven days after spraying, differences were only observed between Bt_A_1 and BT_K_3 and the control. Finally, these two formulations were evaluated under field conditions. The mortality rates caused by Bt_A_1 and BT_K_3 were 77.2% and 85.3%, respectively. These findings show that commercial formulations of B. thuringiensis subsp. aizawai (Bt_A_1) and B. thuringiensis var. aizawai (BT_K_3) exhibit high biological activities against S. impressella larvae and can be included in the integrated management of S. impressella. info:eu-repo/semantics/publishedVersion

Our work reports on the establishment of the neotropical parasitoid Dolichogenidea gelechiidivoris Marsh (Hymenoptera: Braconidae) for the first time in Europe. This larval parasitoid has been recorded in samples collected in commercial tomato crops in Catalonia (North-eastern Spain) from 2016 to the present. Dolichogenidea gelechiidivoris is considered to be a new biocontrol agent among the resident parasitoid complex of Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). info:eu-repo/semantics/acceptedVersion

Didymella pinodella is the major pathogen of the pea root rot complex in Europe. This wide host range pathogen often asymptomatically colonizes its hosts, making the control strategies challenging. We developed a real-time PCR assay for the detection and quantification of D. pinodella based on the TEF-1 alpha gene sequence alignments. The assay was tested for specificity on a 54- isolate panel representing 35 fungal species and further validated in symptomatic and asymptomatic pea and wheat roots from greenhouse tests. The assay was highly consistent across separate qPCR reactions and had a quantification/detection limit of 3.1 pg of target DNA per reaction in plant tissue. Cross-reactions were observed with DNA extracts of five Didymella species. The risk of cross contamination, however, is low as the non-targets have not been associated with pea previously and they were amplified with at least 1000-fold lower sensitivity. Greenhouse inoculation tests revealed a high correlation between the pathogen DNA quantities in pea roots and pea root rot severity and biomass reduction. The assay also detected D. pinodella in asymptomatic wheat roots, which, despite the absence of visible root rot symptoms, caused wheat biomass reduction. This study provides new insights into the complex life style of D. pinodella and can assist in better understanding the pathogen survival and spread in the environament. info:eu-repo/semantics/publishedVersion

The cultivation of the ectomycorrhizal fungus Tuber melanosporum has considerably spread in recent years throughout the world. During the first years of truffle cultivation, weed control is a key practice to improve the establishment of host trees and the proliferation of the fungus in the soil. Glyphosate is nowadays the most commonly used herbicide in Spanish truffle orchards. We explored the effect of glyphosate on the proliferation of T. melanosporum mycorrhizae, on extraradical mycelium and on the inoculum potential of T. melanosporum spores in greenhouse experiments using Quercus ilex seedlings as host plants. No detrimental effect on the secondary infection of T. melanosporum was found after three sequential glyphosate applications in young seedlings during one vegetative period. Instead, a change in the distribution of fine roots and T. melanosporum mycorrhizae along soil depth was observed. On the other hand, results indicate that high application rates of glyphosate hinder the infectivity of T. melanosporum spore inoculum, without apparent impact on the host performance. Our results suggest that glyphosate has the potential to jeopardise the role of the soil spore bank as inoculum source for the colonisation of new roots, also raising the question of whether glyphosate could hinder the presumed role of spores in sexual mating. info:eu-repo/semantics/acceptedVersion

Red leaf blotch (RLB) disease of almond, caused by Polystigma amygdalinum, is an important foliar disease in most production regions of the Mediterranean basin and the Middle East because severe infections may cause a premature defoliation of the tree. Some key aspects on the epidemiology of P. amygdalinum were studied in multiyear trials in two almond-growing regions in Spain, which included the seasonal development of perithecia and production and germination of ascospores along with the disease incubation and plant infectivity periods. Our results showed that primary inoculum was available in extended periods (January to August). Significant differences in ascospore amounts among regions, higher in the southern Andalusia and lower in the northern Catalonia, and years of study were detected. The factors geographical location, sampling period, and evaluation year were found significant on the development of P. amygdalinum perithecia. Variable ascospore germination rates were observed from April to July: >15% but rarely exceeding 30%. The RLB infectivity period in Catalonia extended from March to mid-June, whereas in Andalusia it was from March to May. The incubation period was mainly in a range of 5 to 10 weeks in Catalonia. The environmental conditions of October to January influence the available ascospore amounts in the next season. RLB infection occurs in spring to summer when mean temperatures are in the range 10 to 20°C. These results represent the first step in developing a prediction model of the disease that might serve as a tool for the control of RLB. info:eu-repo/semantics/acceptedVersion

info:eu-repo/semantics/publishedVersion

This paper highlights the potential of using polarimetric methods for the inspection of plant diseased tissues. We show how depolarizing observables are a suitable tool for the accurate discrimination between healthy and diseased tissues due to the pathogen infection of plant samples. The analysis is conducted on a set of different plant specimens showing various disease symptoms and infection stages. By means of a complete image Mueller polarimeter, we measure the experimental Mueller matrices of the samples, from which we calculate a set of metrics analyzing the depolarization content of the inspected leaves. From calculated metrics, we demonstrate, in a qualitative and quantitative way, how depolarizing information of vegetal tissues leads to the enhancement of image contrast between healthy and diseased tissues, as well as to the revelation of wounded regions which cannot be detected by means of regular visual inspections. Moreover, we also propose a pseudo-colored image method, based on the depolarizing metrics, capable to further enhance the visual image contrast between healthy and diseased regions in plants. The ability of proposed methods to characterize plant diseases (even at early stages of infection) may be of interest for preventing yield losses due to different plant pathogens., We acknowledge the financial support of Spanish MINECO (RTI2018-097107-B-C31, and Fondos FEDER); Catalan Government (2017-SGR-001500). J. L. was supported by the CERCA Program, Generalitat de Catalunya., Introduction Results Polarimetric analysis of chlorosis and necrosis Pseudo-colored approach Discussion Methods Sample description Mueller–Stokes formalism Polarimetric observables Complete image Mueller polarimeter Data availability References Acknowledgements Author information Ethics declarations Additional information Supplementary Information Rights and permissions About this article Comments

Bitter rot of apple (Malus × domestica Borkh.) is a cosmopolitan disease affecting fruit and causes considerable losses worldwide. In September 2020, symptoms of bitter rot were observed on ‘Pink Lady’ apples in two orchards (~2.5 ha each) in Gualta, Catalonia, Spain (42.03803 N, 3.09831 E, and 42.03942 N, 3.10931 E). Early symptoms consisted of light brown and sunken circular lesions (1-4 mm) that enlarged over time, later becoming dark brown and water soaked, and extending cone-shaped toward the core. Sporulation was mostly noticed in larger lesions. Estimated incidence was 2% and 20% of 150 trees surveyed in each orchard, respectively. Twenty-one fungal isolates were obtained from diseased fruit by culturing small pieces of necrotic tissue on potato dextrose agar (PDA) amended with rifampicin at 50 mg/liter. Colonies on PDA looked identical. They were cottony, initially light-gray colored on top and darkening with age; colony reverse initially cream colored and darkening with age. Conidia were produced in orange acervular masses on Spezieller Nährstoffarmer Agar, and were aseptate, hyaline, cylindrical with obtuse ends, and measuring 10.1 to 14.7 × 4.5 to 7.1 μm (average 13.1 ± 1.04 × 5.3 ± 0.67 μm [mean ± SD], n = 50), with a mean length/width ratio 2.6 ± 0.39 (n = 16 isolates). Perithecia were not observed. Based on the conidial morphology, the isolates were tentatively identified as belonging to the Colletotrichum gloeosporioides species complex (Weir et al. 2012). Total genomic DNA was extracted from all isolates and six nuclear regions were amplified and partially sequenced: the internal transcribed spacer region of rDNA (ITS), the mating type protein 1-2-1 gene and the Mat1-2-1-Apn2 intergenic spacer region (ApMAT), actin (ACT), calmodulin (CAL), glyceraldehyde 3-P dehydrogenase (GAPDH), and tubulin (TUB2). The sequences for each region were 100% identical across all isolates. BLAST searches in GenBank showed 99-100% identity with sequences of various C. chrysophilum W.A.S. Vieira, W.G. Lima, M.P.S. Câmara & V.P. Doyle strains including the ex-type CMM4268 (Vieira et al. 2017). Sequences of the representative isolate CJL1080 were deposited in GenBank (ACT, MZ488944; ApMAT, MZ442299; CAL, MZ488945; GAPDH, MZ488946; ITS, MZ443972; TUB2, MZ442300). A multilocus phylogenetic analysis through Bayesian inference conducted with the obtained sequences and reference ones (Khodadadi et al. 2020) revealed that our isolates clustered well within C. chrysophilum, as suggested by BLAST results. To confirm Koch’s postulates, isolates CJL1080 and CJL1095 were inoculated on ‘Pink Lady’ apples. Six surface-sterilized fruits per isolate were wound-inoculated four times each with either 20 μl of a conidial suspension (105 conidia/ml) or sterile distilled water (control). After 7 days of incubation in a moist chamber at 22°C, symptoms compatible with Colletotrichum infection were observed around the wounds, whereas control inoculations remained symptomless. The fungus was reisolated from all the lesions and identified through its morphological traits and DNA sequencing (ApMat, CAL, and GAPDH). No fungus was isolated from the controls. Taxa of the C. gloeosporioides species complex causing bitter rot have been recently reported in Europe (Grammen et al. 2019; Nodet et al. 2019). This is the first report of C. chrysophilum causing apple bitter rot in Spain, which expands the knowledge on the geographic distribution of this important pathogen of apple in Europe. info:eu-repo/semantics/publishedVersion

Groundwater pollution has increased in recent years due to the intensification of agricultural and livestock activities. This results in a significant reduction in available freshwater resources. Here, we have studied the long term assessment of a green technology (1-4 L/day) based on a photobioreactor (PBR) containing immobilised microalgae-bacteria in polyurethane foam (PF) followed by a cork filter (CF) for removing nitrates, pesticides (atrazine and bromacil), and antibiotics (sulfamethoxazole and sulfacetamide) from groundwater. The prototype was moderately effective for removing nitrates (58%) at an HRT of 8 days, while its efficiency decreased at a HRT of 4 and 2 days (, The authors wish to thank the financial support of the European Union through the project LIFE18 ENV/ES/000199 and the Spanish Ministry of Science, Innovation and Universities through Project CTM2017-91355-EXP. Finally, European Commission (Erasmus program) and Government of Chile for supporting Lorenzo Rambaldo and Héctor Avila Cortés's visit at IDAEA-CSIC in Barcelona, Spain.

The recent spread of the African citrus psyllid, Trioza erytreae, one of the vectors of the devastating citrus disease, Huanglongbing (HLB), to parts of mainland Europe has created considerable concern. In this study, we show the efficacy of several insecticides with varying modes of action on different developmental stages of T. erytreae. In laboratory trials, spinetoram caused the highest mortality in T. erytreae eggs (between 80 and 90%), while dimethoate, lambda cyhalothrin, spinetoram, cyantraniliprole, and paraffin oil showed over 90% mortality on nymphs. Dimethoate, spinetoram and paraffin oil also demonstrated high efficacy against adults. In winter field conditions, dimethoate showed the best results to control T. erytreae nymph populations, and lambda cyhalothrin showed persistent egg control. Our results support the use of different insecticides to control T. erytreae for adults in winter, and for egg and nymph populations in spring and summer. info:eu-repo/semantics/publishedVersion

Acknowledgments: This research is part of the doctoral dissertation of the author G.P.-S., enrolled in the Ph.D. program in Plant Biology and Biotechnology at the Universitat Autònoma de Barcelona, Spain Red leaf blotch (RLB) of almond, caused by Polystigma amygdalinum, is an important foliar disease of this nut tree in the Mediterranean basin and especially in Spain. In recent years, the control of this disease has become a key factor in the management of Spanish almond orchards. The management of RLB is not easy due to intrinsic factors of the disease (e.g., long infection and latency periods) and the low number of registered fungicides in this country. From 2015 to 2019, different field trials were conducted in the Lleida region, NE Spain, to evaluate the efficacy of several fungicide products and of application strategies to control this disease. Systemic fungicides, which included fluopyram, trifloxystrobin, and mixtures of fluopyram + trifloxystrobin and pyraclostrobin + boscalid, performed better than contact and penetrant products and showed up to 90% control against RLB. However, the efficacy of the tested fungicides varied depending on the year. In terms of application strategies, when fungicide applications were conducted following specific meteorological conditions (after 15 days from >15 mm rainfalls with ≈10-15C as the minimum average temperature), their efficacy was comparable to that of calendar-based treatments (every 14, 21, or 31 days from petal fall) but with fewer applications (depending on the year, 2-4 applications as compared with 5-9 for calendar treatments).

The Neotropical parasitoid wasp Dolichogenidea gelechiidivoris (Marsh, 1975) (Hymenoptera: Braconidae), one of the most important biocontrol agents of the South American tomato pinworm Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae), is reported for the first time from Africa, from tomato grown in open fields and greenhouses in several regions of Algeria. Color photos of specimens from Algeria, Spain and South America, as well as the holotype and one paratype are provided. Morphological and molecular details to better characterize and recognize the species are also provided. We speculate that D. gelechiidivoris arrived accidentally to Algeria from Spain, where it has recently been reported. The consequences for future biocontrol projects against T. absoluta in Africa are discussed.

The Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera Tephritidae), is one of the most devastating agricultural pests worldwide. The kaolin particle film has been demonstrated to effectively control C. capitata on several crops although several studies have proved that kaolin treatments may alter the agroecosystem entomofauna, and specifically in citrus crops. The aim of this work was to study, under laboratory conditions, the efficacy of different kaolin particle film concentrations (1.5%, 2.5%, 3%, 5% and 6% w/v) applied on orange fruits cv “Valencia Late” to optimize its use against C. capitata in citrus groves. We assessed the effect of different kaolin particle film concentrations on the fruit acceptance, repellence, behavioural response, and efficacy fruit infestation. Through all the specific approaches, the 2.5% kaolin treatments applied in two layers successfully reduced the fruit infestation by C. capitata. This processed kaolin treatment should offer efficacy in real field conditions as satisfactory as conventional pesticides towards high populations. info:eu-repo/semantics/publishedVersion

Spotted wing drosophila (SWD) causes significant economic loss in fruit crops to growers worldwide. There is immediate need for efficacious and selective monitoring tools that can detect infestations early. Previously, volatile organic compounds derived from apple were studied and a quinary chemical component blend (QB) was identified as the key SWD attractant in a blueberry orchard in the United States. This study’s aim was to determine whether previously observed QB efficacy, selectivity, and early detection levels could be attained within raspberry and cherry fields in the USA and Europe. Results demonstrated that sticky trap baited QB dispenser provided earlier SWD detection potential than the usually adopted apple cider vinegar (ACV) trap. The number of SWD captured/trap by QB baited trapping systems was significantly lower than that of the ACV trap. However, percent SWD/trap of QB baited traps was same within cherry. Lower non-target capture will save farmer/grower’s labor and time allocated to traps installation and drosophila species identification. Within the USA, SWD selectivity of QB baited liquid traps was consistently greater than sticky trap in raspberry field, suggesting that the QB dispenser can be an alternative to the standard ACV lure and that trap design could improve selectivity further.

To understand trophic interactions and the precise ecological role of each predatory species, it is important to know which arthropod and plant resources are used by generalist predators in agroecosystems. Molecular approaches, such as the use of high-throughput sequencing (HTS), play a key role in identifying these resources. This study develops a multiprimer metabarcoding approach for screening the most common trophic interactions of two predatory arthropods with contrasting morphologies, Rhagonycha fulva (Coleoptera: Cantharidae) and Anthocoris nemoralis (Hemiptera: Anthocoridae) collected from a peach crop. To reduce the time and cost of this metabarcoding approach, we first evaluated the effect of using two different predator-pools of different size (10 and 23 individuals of the same species). We also used our system to analyze the performance of one and two primer pairs in the same library. Our results show that the analysis of 23 individuals together with the use of two primer pairs in the same library optimize the HTS analysis. Using these best-performing conditions, we then analyzed the entire bodies of field-collected predators as well as the washing solutions used to clean the insect bodies. We were able to identify both gut content (i.e., diet) and external pollen load (i.e., on the insects’ bodies). This study also demonstrates the importance of washing predatory insects’ bodies prior to HTS analysis when the target species have a considerable size (>10 mm) and hairy structures. This metabarcoding approach has significant potential for the study of trophic links in agriculture, revealing expected and unexpected trophic relationships. info:eu-repo/semantics/acceptedVersion

Alternaria spp. is the causal agent of apple leaf blotch and fruit spot, diseases of recent appearance in Spain. The overwinter inoculum of Alternaria spp. is the source of primary infections in apple, thus the aim of this work was to optimize the control of infection through two environmentally friendly inoculum-management strategies, the removal of winter fallen leaves and the treatment of leaves with the biological agent Trichoderma asperellum to inhibit or prevent inoculum development in commercial orchards. The results of commercial orchard trials showed that leaf aspiration and application of T. asperellum on the ground have efficacy to reduce fruit spot between 50 and 80% and leaf blotch of between 30 and 40% depending on the year. The efficacies on the reduction of leaf blotch were slightly lower than of fruit spot. Disease reduction has been related to a reduction of total spores released during the season. Results of dynamics of spore release indicate that factors influencing spore release were rainfall and temperature. In conclusion, the use of environmentally friendly strategies combined with standard fungicides, and with monitoring environmental conditions, might allow a reduction in the number of phytosanitary applications, thus achieving the goal of reducing their use. info:eu-repo/semantics/publishedVersion

In this study, the predatory mite Transeius montdorensis (Acari, Phytoseiidae) was tested for the control of the tomato russet mite (TRM) Aculops lycopersici (Acari, Eriophyidae) in experiments with small plants, under semi-field and crop conditions. The releasing strategy consisted of repeatedly introducing the predator together with additional breeding prey. The predator was able to move and disperse to the upper part of the tomato plant where the TRM seeks refuge. At the crop level, significant reductions in TRM populations were observed that resulted in a significantly higher yield compared to the conventional control plot, where pesticides were used to control the pest. Caution should be taken when extreme temperatures or humidity occur as they could be deleterious to the predator population. Hence, crop practices should include the management of environmental parameters in the greenhouse to ensure the success of this TRM-control strategy. In conclusion, this biological approach seems to be an effective measure to control the pest and should be further implemented at crop level. info:eu-repo/semantics/publishedVersion

Legume/cereal intercropping has the potential to maximize the use of resources to raise yields due to enhanced nitrogen (N) fixation by legume root nodules, while high N fertilization may inhibit the nodulation of legume. However, whether legume/cereal intercropping can promote the accumulation of soil N storage with N fertilization and its underlying mechanism are less clear. Here, we evaluated the long-term (5 years) effects of maize/peanut intercropping and mineral N fertilization on peanut soil total N content and soil N cycling functional genes. The experiment includes two planting patterns (peanut maize intercropping and peanut monocropping) with three N fertilization rates (0, 150, and 300 kg N ha−1). Intercropping increased soil total N content (STN) by average 18.2%, and the positive effect of intercropping on STN decreased with N application rate. Highest N application decreased the nodule fresh weight (NFW) by 64.3% and 46.0% in intercropping and monocropping system, respectively. However, intercropping has no effect on NFW. Intercropping increased the nifH gene abundance by average 26.5%. SEM analysis indicated that NFW and nifH gene abundance combined can explain 46% of the variance of STN. Our results indicate that biological N fixation but not mineral N fertilization enhances the accumulation of N in soil planted with peanut in maize/peanut intercropping system. info:eu-repo/semantics/publishedVersion

In rice ecosystems, seeding densities can be adjusted to compensate for lower nitrogen levels that reduce GHG emissions, or to increase farm profitability. However, density-induced changes to plant anatomy could affect herbivore-rice interactions, and alter arthropod community dynamics. We conducted an experiment that varied transplanting density (low or high), nitrogenous fertilizer (0, 60 or 150 kg added ha−1) and rice variety (resistant or susceptible to phloem-feeding insects) over two rice-growing seasons. Yields per plot increased with added nitrogen, but were not affected by variety or transplanting density. Planthopper and leafhopper densities were lower on resistant rice and in high-density field plots. Nitrogen was associated with higher densities of planthoppers, but lower densities of leafhoppers per plot. High planting densities and high nitrogen also increased rodent damage. The structure of arthropod herbivore communities was largely determined by season and transplanting density. Furthermore, two abundant planthoppers (Sogatella furcifera (Horváth) and Nilaparvata lugens (Stål)) segregated to low and high-density plots, respectively. The structure of decomposer communities was determined by season and fertilizer regime; total decomposer abundance increased in high-nitrogen plots during the dry season. Predator community structure was determined by season and total prey abundance (including decomposers) with several spider species dominating in plots with high prey abundance during the wet season. Our results indicate how rice plasticity and arthropod biodiversity promote stability and resilience in rice ecosystems. We recommend that conservation biological control, which includes a reduction or elimination of insecticides, could be promoted to attain sustainable rice production systems. info:eu-repo/semantics/publishedVersion

Diptera are among the most serious arthropod pests affecting mushroom crops. Phorid flies, especially Megaselia halterata, have traditionally been globally considered as a minor pest, although they are a very important problem on Spanish mushroom farms. The concerns with respect to the phorid fly populations have recently increased, notably jumping from being a minor to major pest in India, UK and the USA, where yield losses ranging between 10% and 40% were reported. This review updates and summarizes the available literature regarding mushroom phorid populations, stressing the natural distribution of phorids and their seasonal distribution, their biology within the growing substrates and the initial sources of infestation on mushroom farms. Moreover, the review also highlights the scarce available tools for their control and the current alternatives to chemical products. info:eu-repo/semantics/publishedVersion

Conservation biological control involves manipulation of the environment to enhance the efectiveness of natural enemies in controlling crop pests. In this study, we combined historical data, sticky trap sampling of tomato greenhouses and beat sampling of adjacent vegetation to identify which greenhouse characteristics, habitat management practices and landscape features favour an early colonisation of tomato greenhouses by the key mirid predator Macrolophus pygmaeus and its establishment in NE Spain. Results show that landscape composition and the use of Calendula ofcinalis banker plants inside the greenhouse are key factors. In general, greater amounts of herbaceous semi-natural cover at the landscape scale promoted M. pygmaeus colonisation, while the use of C. ofcinalis banker plants encouraged M. pygmaeus colonisation independently of the landscape context. We identifed host plants adjacent to tomato greenhouses that sustain M. pygmaeus populations; however, they did not have a major efect on M. pygmaeus colonisation compared to larger landscape and banker plant efects. Early colonisation of greenhouses by this predator species also translated into lower accumulated incidence of pests at the end of the sampling period. This study demonstrates the importance of active habitat management practices in promoting the early arrival of M. pygmaeus in greenhouses with delayed spontaneous colonisation. This study was funded by EU-funded projects, EUCLID (Project Number: 633999-2) and EMPHASIS (Project Number: 634179-2), the project AGL2016-77373-C2-1-R (Spanish Ministry of Economy and Competitiveness) and the CERCA Programme of the Generalitat de Catalunya. AA was partly supported by a Ramón Areces fellowship while writing this manuscript.

Trioza erytreae is one of the vectors of Huanglongbing (HLB), the main global citrus groves threat. Since its recent detection in the north-western Iberian Peninsula (Spain and Portugal), its contention and eradication have been a priority to prevent its spread. For the biological control of T. erytreae, it is important to understand the role that each potential natural enemy could have. With the aim to determine which predators have incorporated T. erytreae into their diet, a PCR-based method has been developed for the specific detection of T. erytreae in their gut contents. For this, a pair of specific primers was designed from the mitochondrial cytochrome c oxidase subunit I (COI) region. Specificity of this pair of primers was studied and feeding trials with two predator species were conducted to determine the decay rates of T. erytreae within their gut. None of the non-target species was amplified, showing the high specificity of these T. erytreae primers. Feeding trials showed 4.8h and 4.5h half-life time detections of T. erytreae ingested by Chrysoperla carnea and Cryptolaemus montrouzieri, respectively. Finally, field-collected generalist predators of T. erytreae-infested citrus trees from the Canary Islands and Galicia (Spain), were analysed by conventional PCR for the presence of T. erytreae in their guts. Results showed that a wide range of predator taxa ingested the target prey, like the families Coccinellidae, Anthocoridae, Chrysopidae, Hemerobiidae, Forficulidae, Miridae, Syrphidae, Formicidae, Erythraeidae and the order Araneae, with detection percentages ranging from 20 to 100%. These results confirm that most of the analysed generalist predators found in citrus trees could be potential candidates for the biological control of T. erytreae in future biological control programs of this HLB vector. info:eu-repo/semantics/acceptedVersion

Development of conservation biological control programs requires the identification of sources that contribute to predator colonization of crops. Macrolophus pygmaeus (Rambur) (Hemiptera: Miridae) is an efficient polyphagous predator used in biological control programs in vegetable crops in Europe. We have developed a marking method based on spraying with a solution of the brine shrimp Artemia spp. (Anostraca: Artemiidae) cysts, followed by a PCR detection of Artemia DNA to monitor M. pygmaeus dispersal from banker plants to tomato crops. Experiments conducted in climatic chambers show that the topical application of this marking solution on M. pygmaeus does not significantly reduce adult longevity and that it is detected up to 6 d after the application. When this Artemia solution was applied on Calendula officinalis L. banker plants harboring M. pygmaeus and maintained outdoors, Artemia DNA was still detected on 62% of the insects after 6 d. The conducted field applications in commercial greenhouses have confirmed the usefulness of this method to monitor M. pygmaeus dispersal from banker plants to a newly planted tomato crop. This method can be used to assess arthropod movement, being an interesting molecular approach for further improving future pest management strategies. info:eu-repo/semantics/acceptedVersion

Neonicotinoids are used to protect citrus trees against pests. Dissipation and persistence of neonicotinoids in pollen and nectar of citrus trees after foliar applications and their potential exposure to pollinators have not been well characterized. Field studies were conducted using three orange and one mandarin varieties to compare the imidacloprid and thiamethoxam residue levels and their decline in pollen and nectar after treatments in pre-bloom close to flowering period and their persistence 1 yr after treatment. The possible risk to honeybees was assessed. In nectar, thiamethoxam and imidacloprid residues were between 61 and 99% lower than in pollen, depending on the citrus variety or/and the days after treatment when applied close to blooming. At the end of the flowering period, imidacloprid in pollen and nectar was not detected in the mandarin variety after treatment in pre-bloom, whereas for thiamethoxam, no residues were detected in nectar but 10 ng/g was detected in pollen. There were no quantifiable levels of residues for either neonicotinoids in pollen or nectar during the flowering period of the following year. Neonicotinoid residue levels and their decline in nectar and pollen in citrus depended on the timing of applications relative to flowering and on the citrus variety. The absence of neonicotinoid residues 1 yr out after foliar applications in all varieties assayed demonstrated that none of the neonicotinoids tested were persistent. The results could be different in other citrus varieties, and therefore, also the exposure assessment for managed pollinators.

In recent decades, wild cherry has been one of the species most widely used for reforestation in Europe. Studies aiming to select and improve trees to give them the best growth rates and wood properties have increased in response to growers’ demands. However, information relating to key physiological processes such as transpiration or stomatal conductance and to the effect of the common practice of pruning on plant–water relations is scarce. The main objective of this study was to assess the effects of environmental conditions on canopy conductance dynamics. Its secondary objective was to examine the short- and medium-term effects of branch pruning on tree transpiration, growth and derived water productivity. To this end, we measured sap flow in an experimental plantation where trees were subjected to drip irrigation and rain-fed conditions and where variables characterizing climate, soil and tree growth were also monitored. The results demonstrated that the Jarvis–Stewart approach was appropriate for studying the responses of canopy conductance to environmental factors. As well as the role of vapour pressure deficit and net radiation in controlling the daily variations of canopy conductance, the single effects of decreasing soil water content (optimum relative extractable water, REW, higher than 0.4) and increasing air temperature (optimum of 21 °C), as summer conditions approached, were correctly incorporated into the modelling exercise. Soil water content exerted the greatest control on canopy conductance for trees growing under rain-fed conditions, while air temperature did for irrigated trees. Pruning significantly reduced transpiration to about 35% when pre- and post-sub-periods were compared, but also affected annual water productivity regardless of the irrigation treatment. To assess the long-term effects of pruning on water productivity, measurements in both pruned and unpruned trees would be desirable. © 2019 Elsevier B.V., This research was financially supported by the GRIFO (AGL2010-21012) and CONSOLIDER-MONTES (CSD 2008-00040) projects. A.J. Molina is beneficiary of a Juan de la Cierva post-doctoral fellowship. A. Galindo is beneficiary of a Ramón Areces foundation post-doctoral fellowship. The field work of Eulalia Serra, Beatriz Grau, Marc Ferrer and Cristian Morales is greatly appreciated. We also want to thank the work of two anonymous reviewers in improving the quality of the manuscript.