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1.
PLoS One ; 18(10): e0291431, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37862335

RESUMEN

As the current climate crisis intensifies, drought resistant crops are becoming more important due to their ability to withstand the increasingly hotter and drier summers. Such crops are valuable for pollinators as they provide food resources for wild and managed species. The carob tree (Ceratonia siliqua L.) represents an example of a heat- and drought- resistant crop, able to grow in dry areas with practically no inputs. The current study assessed over two growing seasons the diversity of wild bees and other pollinators relying on carob flowers, as well as the contribution of animal pollination to carob production. Carob flowers were subjected to two treatments: Open pollination, where inflorescences were left untreated, and wind pollination, where inflorescences were bagged in a mesh during blooming. Weekly observations during blooming showed that Apis mellifera was the most frequent floral visitor followed by wild bees and wasps. Carob flowers were visited by at least 10 different wild bee species. Open-pollinated flowers produced significantly more pods, with the benefit ranging from 4 to 16 times higher production, depending on the region. Open pollination led to pods with greater weight, length and number of seeds compared to pods derived from wind pollination. The results of the current study highlight the importance of animal pollination to carob production, as well as the significance of carob trees to wild bee conservation.


Asunto(s)
Biodiversidad , Avispas , Abejas , Animales , Productos Agrícolas , Semillas , Flores , Polinización
2.
Plants (Basel) ; 10(6)2021 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-34205988

RESUMEN

The preservation of fresh produce quality is a major aim in the food industry since consumers demand safe and of high nutritional value products. In recent decades there has been a turn towards the use of eco-friendly, natural products (i.e., essential oils-EOs) in an attempt to reduce chemical-based sanitizing agents (i.e., chlorine and chlorine-based agents). The aim of this study was to evaluate the efficacy of an eco-friendly product (EP-based on rosemary and eucalyptus essential oils) and two different application methods (vapor and dipping) on the quality attributes of tomato fruits throughout storage at 11 °C and 90% relative humidity for 14 days. The results indicated that overall, the EP was able to maintain the quality of tomato fruits. Dipping application was found to affect less the quality attributes of tomato, such as titratable acidity, ripening index and antioxidant activity compared to the vapor application method. Vapor application of 0.4% EP increased fruit's antioxidant activity, whereas tomatoes dipped in EP solution presented decreased damage index (hydrogen peroxide and lipid peroxidation levels), activating enzymes antioxidant capacity (catalases and peroxidases). Moreover, higher EP concentration (up to 0.8%) resulted in a less acceptable product compared to lower concentration (0.4%). Overall, the results from the present study suggest that the investigated EP can be used for the preservation of fresh produce instead of the current commercial sanitizing agent (chlorine); however, the method of application and conditions of application must be further assessed for every commodity tested.

3.
J Appl Ecol ; 57(4): 681-694, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-32362684

RESUMEN

Agricultural intensification and associated loss of high-quality habitats are key drivers of insect pollinator declines. With the aim of decreasing the environmental impact of agriculture, the 2014 EU Common Agricultural Policy (CAP) defined a set of habitat and landscape features (Ecological Focus Areas: EFAs) farmers could select from as a requirement to receive basic farm payments. To inform the post-2020 CAP, we performed a European-scale evaluation to determine how different EFA options vary in their potential to support insect pollinators under standard and pollinator-friendly management, as well as the extent of farmer uptake.A structured Delphi elicitation process engaged 22 experts from 18 European countries to evaluate EFAs options. By considering life cycle requirements of key pollinating taxa (i.e. bumble bees, solitary bees and hoverflies), each option was evaluated for its potential to provide forage, bee nesting sites and hoverfly larval resources.EFA options varied substantially in the resources they were perceived to provide and their effectiveness varied geographically and temporally. For example, field margins provide relatively good forage throughout the season in Southern and Eastern Europe but lacked early-season forage in Northern and Western Europe. Under standard management, no single EFA option achieved high scores across resource categories and a scarcity of late season forage was perceived.Experts identified substantial opportunities to improve habitat quality by adopting pollinator-friendly management. Improving management alone was, however, unlikely to ensure that all pollinator resource requirements were met. Our analyses suggest that a combination of poor management, differences in the inherent pollinator habitat quality and uptake bias towards catch crops and nitrogen-fixing crops severely limit the potential of EFAs to support pollinators in European agricultural landscapes. Policy Implications. To conserve pollinators and help protect pollination services, our expert elicitation highlights the need to create a variety of interconnected, well-managed habitats that complement each other in the resources they offer. To achieve this the Common Agricultural Policy post-2020 should take a holistic view to implementation that integrates the different delivery vehicles aimed at protecting biodiversity (e.g. enhanced conditionality, eco-schemes and agri-environment and climate measures). To improve habitat quality we recommend an effective monitoring framework with target-orientated indicators and to facilitate the spatial targeting of options collaboration between land managers should be incentivised.


La intensificación agrícola y la consecuente pérdida de hábitats de alta calidad son desencadenantes clave del declive de los insectos polinizadores. Con el objetivo de disminuir el impacto ambiental de la agricultura, la Política Agrícola Común (PAC) de la UE de 2014 definió un conjunto de medidas para hábitats y paisajes (Áreas de Enfoque Ecológico: EFA por sus siglas en inglés) que los agricultores podían seleccionar como requisito para recibir pagos agrícolas básicos. Para informar la reforma de la PAC a partir a 2020, realizamos una evaluación a escala europea para determinar cómo las diferentes opciones de EFA varían en su potencial para asistir a los insectos polinizadores bajo un manejo estándar y amigable con los polinizadores, así como su aceptación por parte de los agricultores.El proceso estructurado de elicitación Delphi para evaluar las opciones de EFA involucró a 22 expertos de 18 países europeos. Se consideraron los requisitos de los diferentes taxones de polinizadores (es decir, abejorros, abejas solitarias y sírfidos) evaluando cada opción por su potencial para proporcionar forraje, sitios de nidificación y recursos para las larvas.Las opciones de EFA variaron sustancialmente en la cantidad de recursos que se percibía que proporcionan y su efectividad vario geográfica y temporalmente. Por ejemplo, los márgenes de cultivos proporcionan un forraje relativamente bueno durante toda la temporada en el sur y el este de Europa, pero carecen de forraje a principios de temporada en el norte y oeste de Europa. Bajo el manejo estándar, ninguna opción de EFA logró puntuaciones altas en todas las categorías de recursos y en general se percibió una escasez de forraje al final de la temporada.Los expertos identificaron oportunidades sustanciales para mejorar la calidad del hábitat mediante la adopción de un manejo amigable con los polinizadores. Sin embargo, mejorar la gestión por sí solo es poco probable que garantice que se cumplan todos los requisitos necesarios para los polinizadores. Nuestro análisis sugiere que una combinación de manejo inadecuado, diferencias de calidad inherentes a los distintos hábitat y el sesgo de aceptación hacia cultivos de cobertura y cultivos que fijan nitrógeno limitan severamente el potencial de los EFA para apoyar a los polinizadores en los paisajes agrícolas europeos. Implicaciones políticas. Para conservar a los polinizadores y ayudar a proteger los servicios de polinización, nuestro estudio destaca la necesidad de crear una variedad de hábitats interconectados y bien administrados que se complementen entre sí en los recursos que ofrecen. Para lograr esto, la PAC post­2020 debe integrar los diferentes vehículos de implementación destinados a proteger la biodiversidad (por ejemplo, condicionalidad mejorada, esquemas ecológicos y medidas agroambientales y climáticas). Para mejorar la calidad del hábitat, recomendamos un marco de monitoreo efectivo con indicadores orientados a objetivos y incentivar la colaboración entre los administradores de las tierras.


L'intensification agricole et la perte associée d'habitats semi­naturels sont les principaux moteurs du déclin des insectes pollinisateurs. Dans l'intention de réduire l'impact environnemental de l'agriculture, la politique agricole commune (PAC) de l'UE de 2014 a défini un ensemble d'habitats et d'éléments paysagers (surfaces d'intérêt écologique: SIE) dans la mise en place ou le respect desquels les agriculteurs pouvaient s'engager comme condition pour bénéficier d'aides économiques européennes (droit au paiement de base). Pour éclairer la PAC post­2020, nous avons évalué à l'échelle européenne et à dire d'expert, d'une part les potentialités des diverses SIE à favoriser les insectes pollinisateurs, via une gestion standard et via une gestion optimisée, et d'autre part l'étendue de l'adoption de ces mesures par les agriculteurs.Un processus structuré d'élaboration et d'agrégation des opinions (méthode Delphi) a fait appel à 22 experts de 18 pays européens pour évaluer les potentialités des diverses SIE. Considérant les traits bioécologiques des principaux taxons pollinisateurs (i.e. bourdons, abeilles solitaires et syrphes), chaque SIE a été évaluée pour son potentiel à fournir des ressources trophiques et des sites de reproduction (sites de nidification pour les bourdons et abeilles, sites de ponte et développement larvaire pour les syrphes).Les SIE différaient considérablement les unes des autres sur les ressources qu'elles étaient censées offrir et leur efficacité variait géographiquement et temporellement. Par exemple, les bords de champ peuvent fournir des ressources trophiques tout au long de l'année en Europe du Sud et de l'Est mais pas en début de saison en Europe du Nord et de l'Ouest. En cas de gestion standard, aucun type de SIE n'atteint de score élevé pour aucun type de ressource, et une période de disette alimentaire survient en fin de saison.Les experts ont mis en évidence de possibles et substantielles améliorations des SIE par le biais de leur gestion optimisée. Cependant, cette seule amélioration ne garantit pas la fourniture de ressources suffisantes aux pollinisateurs des paysages agricoles européens. Pour cela, des habitats spécifiques doivent être favorisés, dont la mise en place ne doit pas être entravée par un choix massif de SIE à base de cultures intermédiaires pièges à nitrates ou fixatrices d'azote. Implications politiques. Pour préserver les pollinisateurs et le service de pollinisation des plantes entomophiles, notre étude souligne la nécessité de créer une diversité d'habitats interconnectés, gérés de façon optimale, qui se complètent mutuellement dans les ressources qu'ils offrent. Pour atteindre cet objectif, la PAC post­2020 doit adopter une vision holistique de la mise en œuvre des différents leviers de protection de la biodiversité (e.g. éco­conditionnalité renforcée, programmes verts ou 'eco­schemes', mesures agro­environnementales et climatiques). Pour réellement améliorer la qualité des habitats, nous recommandons des suivis efficaces de la biodiversité à l'aide d'indicateurs pertinents. Enfin, pour optimiser la disposition spatiale des SIE et leur connectivité, la collaboration entre les différents gestionnaires des espaces agricoles doit être encouragée.


A intensificação agrícola e a perda associada de habitats de elevada qualidade são os principais factores que impulsionam o declínio dos insetos polinizadores. A fim de mitigar o impacto ambiental da agricultura, a Política Agrícola Comum (PAC) da UE, de 2014, definiu um conjunto de atributos ou estruturas do habitat e da paisagem, designadas de Áreas Foco Ecológico (AFEs) que devem ser mantidas pelos agricultores como requisito para obter as ajudas económicas previstas nas medidas agroambientais. No presente trabalho realizamos uma avaliação à escala europeia das diferentes opções destas estruturas, a fim de munir a PAC pós­2020, com informação sobre a importância das AFEs. Estas variam muito quanto ao seu potencial no apoio às populações de polinizadores, de acordo com a extensão da sua aceitação pelos agricultores e das práticas adoptadas por estes na sua gestão, que podem consistir em práticas padrão ou práticas mais amigáveis para os polinizadores.Um processo estruturado, com base na técnica de elicitação de Delphi foi desenvolvido, envolvendo 22 especialistas de 18 países europeus, com o objectivo de avaliar as opções de AFEs previstas na PAC. Esta avaliação levou em consideração os requisitos do ciclo de vida dos taxa dos principais polinizadores, ou seja, as abelhas, as abelhas solitárias e os sirfídeos ou moscas­das­flores. Cada AFE foi avaliada quanto ao seu potencial para fornecer alimento, locais de nidificação, e recursos para as larvas dos sirfídeos.A percepção quanto à eficácia das AFEs como fonte de recursos (alimento) para os polinizadores variou substancialmente, do ponto de vista quer geográfico, quer temporal (época do ano). Por exemplo, a AFE, faixas verdes nas margens do campo são consideradas uma boa fonte de alimento, no sul e leste da Europa, durante todo ano, mas ineficazes, no norte e oeste da Europa, no início do ano. Nenhuma EFA alcançou pontuações elevadas na categoria de recursos (fonte de alimento), quando submetida ao maneio padrão, sendo consideradas ineficientes, na segunda metade do ano.Os especialistas envolvidos identificaram oportunidades de melhoria substancial na qualidade do habitat, através da adopção de práticas de maneio das EFAs mais "amigáveis" para com os polinizadores. No entanto, a melhoria das práticas de maneio das EFAs por si só, dificilmente garantirá todos os requisitos necessários para a manutenção das populações de polinizadores. A nossa avaliação sugere que a combinação de práticas de má gestão (maneio), diferenças inerentes à qualidade do habitat dos polinizadores e o aumento do bias que resulta da utilização de espécies de crescimento rápido ou fixadoras de azoto limitam severamente o papel e potencial destas estruturas na manutenção das populações de polinizadores nas paisagens agrícolas europeias. Implicações políticas. A conservação dos polinizadores ajuda a proteger os serviços de polinização providenciados por estes. O nosso estudo destaca a necessidade de criar uma variedade de habitats interconectados e geridos de forma que se complementem na oferta de recursos (alimento, locais de nidificação e recursos para as larvas) aos polinizadores. Para atingir este objectivo, a PAC pós­2020 deve adoptar uma visão holística na implementação das EFAs, que integre os diferentes programas destinados a protecção da biodiversidade (por exemplo, maior condicionalidade, esquemas ecológicos, e medidas agroambientais e de adaptação climática). Para melhorar a qualidade do habitat, recomendamos uma estrutura de monitorização eficaz suportada por indicadores quantitativos e qualitativos orientados para metas, que permitam facilitar a tomada de decisões direcionadas especificamente para as EFAs, e que a colaboração entre os gestores da terra (agricultores) seja incentivada.

4.
Zookeys ; 924: 1-114, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32308528

RESUMEN

Cyprus, the third largest island in the Mediterranean, constitutes a biodiversity hotspot with high rates of plant endemism. The wild bees of the island were studied extensively by the native George Mavromoustakis, a world-renowned bee taxonomist, who collected extensively on the island from 1916 to 1957 and summarised his results in a series of eight Cyprus-specific papers published from 1949 ["1948"] to 1957. The current work represents the first modern checklist of the wild bees of Cyprus, based on a compilation of previous publications, museum specimens and authors' recent collections. Overall, 369 verified wild bee species have been recorded on the island, with eleven species reported from Cyprus for the first time. The island hosts all six of the globally widespread bee families, with Apidae represented by 110 species, Megachilidae with 91, Andrenidae with 76, Halictidae with 72, Colletidae with 19, and Melittidae with 1. Twenty-one of the recorded bee species are endemic (i.e., 5.7 % endemism rate) and Cyprus ranks third after Lesvos and Sicily in known bee species richness among the Mediterranean islands. Previously unpublished records from various locations on Cyprus for 156 previously reported bee species are also provided in the study. The current work provides a baseline for future studies of wild bee diversity on the island of Cyprus and neighbouring regions.

5.
Plant Physiol Biochem ; 130: 658-662, 2018 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-30139552

RESUMEN

Plant response to imposition of biotic and abiotic stresses by inducing their defense mechanisms, with the production of reactive oxygen species (ROS) representing a major defense response. The present work examined the simultaneous impact of two key stress factors, drought and spider mite attack (Tetranychus urticae) in Medicago truncatula plants. Hydrogen peroxide (H2O2), lipid peroxidation (MDA content) and proline content in well-watered and drought-stressed leaves infested by spider mites along with neighboring leaves were examined in order to investigate the local and systemic effect of the two stresses on the antioxidant and osmoprotective response. High levels of lipid peroxidation were recorded in plants under drought stress and plants under combined drought stress and spider mite feeding compared with control plants. Hydrogen peroxide biosynthesis was significantly induced in plants under drought and spider mite attack, with highest levels detected in the feeding leaf (local response). Proline was accumulated in drought stressed-plants, with the highest levels observed in plants exposed to a combination of drought stress and mite feeding. RT-qPCR expression analysis of key genes implicated in ROS metabolism (PAO, DAO, AOX, CuZnSOD, FeSOD, MnSOD) and proline biosynthesis (P5CR, P5CS) pointed to different patterns of regulation between abiotic and biotic stress, as well as their combination. Exposure of plants to both drought stress and attack by spider mites mainly affected the local antioxidant and osmoprotective response of Medicago truncatula, highlighting the relative significance of drought-induced phenomena in combined drought/mite infestation stress responses.


Asunto(s)
Medicago truncatula/fisiología , Tetranychidae , Animales , Antioxidantes/metabolismo , Deshidratación , Regulación de la Expresión Génica de las Plantas/fisiología , Peróxido de Hidrógeno/metabolismo , Peroxidación de Lípido , Medicago truncatula/parasitología , Oxidación-Reducción , Hojas de la Planta/parasitología , Hojas de la Planta/fisiología , Prolina/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Reacción en Cadena en Tiempo Real de la Polimerasa , Superóxido Dismutasa/metabolismo , Transcriptoma
6.
PLoS One ; 10(12): e0144413, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26641652

RESUMEN

The use of agrochemicals particularly pesticides, can hamper the effectiveness of natural enemies, causing disruption in the ecosystem service of biological control. In the current study, the effects of the insecticides thiacloprid and chlorantraniliprole on the functional response curves were assessed for two mirid predator nymphs, Macrolophus pygmaeus Rambur and Nesidiocoris tenuis Reuter. In the absence of insecticides, both predators exhibited a type II functional response when feeding on eggs of the moth Ephestia kuehniella. N. tenuis seems to be a more efficient predator than M. pygmaeus, as model estimated handling time was significantly lower for the former than for the latter. Residual exposure of M. pygmaeus to sublethal concentrations of either insecticide was associated with a change in the asymptote but not the type of the functional response curve. Thiacloprid seems to be the least compatible with M. pygmaeus, as it led to both a significant reduction of the attack rate and an increase in handling time. In contrast, chlorantraniliprole exposure significantly increased the handling time, but not the attack rate of the predator. Residual exposure of N. tenuis to sublethal concentrations of either insecticide did not have a significant effect on the type nor the parameters of the functional response model. The results show that pesticide residues that do not have lethal effects on beneficial arthropods can reduce prey consumption depending on predator species and on likely risks associated with toxicity.


Asunto(s)
Heterópteros/fisiología , Insecticidas/farmacología , Lepidópteros/fisiología , Ninfa/efectos de los fármacos , Conducta Predatoria/efectos de los fármacos , Piridinas/farmacología , Tiazinas/farmacología , ortoaminobenzoatos/farmacología , Animales , Neonicotinoides
7.
Exp Appl Acarol ; 50(3): 243-54, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19771398

RESUMEN

In recent years, grape growers in California reported failures of acaricides against Tetranychus pacificus McGregor. We collected T. pacificus populations from four vineyards and tested them for resistance to bifenazate, propargite and pyridaben. In addition, we sequenced part of the cytochrome b gene of bifenazate-resistant and -susceptible T. pacificus to test for the presence of mutations reported to confer resistance to the congeneric T. urticae. None of the mutations conferring resistance to bifenazate in T. urticae were present in resistant T. pacificus. Resistance levels ranged from full susceptibility to statistically significant 11-fold resistance to pyridaben, sevenfold resistance to bifenazate and fourfold resistance to propargite compared to a susceptible population. Despite the relatively low levels of resistance detected, we estimated that under the conditions of our study the highest field rates of bifenazate and pyridaben application would cause less than 58 and 66% mortality of adult females in the most resistant populations, respectively. In contrast, field rates of propargite application would cause close to 100% mortality in the least susceptible population. These results highlight a potential link between resistance development and reduced field effectiveness for bifenazate and pyridaben. Finally, T. pacificus may be more tolerant to bifenazate and propargite than T. urticae, since the LC(50) values for the susceptible population of T. pacificus were several times higher than LC(50)'s reported for susceptible T. urticae.


Asunto(s)
Acaricidas , Tetranychidae , Vitis/parasitología , Secuencia de Aminoácidos , Animales , California , Carbamatos , Ciclohexanos , Citocromos b/genética , Resistencia a Medicamentos/genética , Femenino , Genotipo , Hidrazinas , Datos de Secuencia Molecular , Mutación , Piridazinas , Análisis de Secuencia de ADN , Tetranychidae/genética
8.
Environ Entomol ; 39(4): 1232-41, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-22127173

RESUMEN

We evaluated the relationships between plant water status and leaf temperature, and between leaf temperature and spider mite (Acari: Tetranychidae) and predatory mite (Acari: Phytoseiidae) populations in eight vineyards in California in 2006 and 2007. Temperature of south-facing leaves increased significantly by 0.8°C for every 1.0°C increase in ambient air temperature, and by 5.3°C for every one MPa drop in leaf water potential. Peak population densities of Pacific spider mite, Tetranychus pacificus McGregor, increased significantly with increasing frequency of leaf temperatures above 31°C. In contrast, peak population densities of Willamette spider mite, Eotetranychus willamettei (McGregor), showed no relationship with the frequency of leaf temperatures above 31°C. This differential relationship between the two mite species and high leaf temperatures is consistent with their upper thresholds for development, which are 40°C for T. pacificus and 31°C for E. willamettei, as identified in a previous study. Predatory mite population densities showed no relationship with peak population densities of either spider mite species during the analysis period, but decreased with the frequency of leaf temperatures above 31°C. In addition, predatory mite population densities were significantly higher on south-facing than interior leaves after adjusting for the effect of leaf temperature. These results help to explain why outbreaks of T. pacificus occur in warmer or water-stressed vineyards, whereas E. willamettei develops higher populations in cooler or well-irrigated vineyards. In addition, these results suggest that regulated deficit irrigation should be implemented with caution, especially in those vineyards with a high risk of T. pacificus outbreaks.


Asunto(s)
Interacciones Huésped-Parásitos , Hojas de la Planta/parasitología , Tetranychidae/fisiología , Vitis/parasitología , Agua/fisiología , Animales , Biodiversidad , California , Deshidratación , Hojas de la Planta/fisiología , Densidad de Población , Temperatura , Vitis/fisiología
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