38 research outputs found

    Polvos de especias arom\ue1ticas para el control del gorgojo del maiz, Sitophilus zeamais Motschulsky, en trigo almacenado

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    The maize weevil, Sitophilus zeamais Motschulsky, is considered one of the most important pests of stored grains. Plant powders from nine seasoning spices were tested in the laboratory to control S. zeamais at 0,5, 1, 2 and 4% (w/w). The variables evaluated were mortality and emergence (F1) of adult insects, grain weight loss and grain germination. The repellent and fumigant effects were evaluated at concentrations of 0.5, 1, 2 and 4%; the experimental design was completely randomized, with four replicates, and the group of treatments was repeated three times. The highest mortality percentages were obtained with Piper nigrum L. at 1% (83.4%), 2% (97.6%) and 4% (100%). The lowest adult insect emergence was obtained with the same treatments more Capsicum annuum var. longum Sendtn., Cinnamomum zeylanicum Blume and Pimpinella anisum L. at 4% (w/w). No significant differences were recorded as regards grain weight loss and germination. All the plant powders tested had a repellent effect on Sitophilus zeamais and no fumigant effect was recorded.El gorgojo del ma\uedz Sitophilus zeamais Motschulsky,es considerado una de las plagas mas importantes de productos almacenados. Se evaluaron, en laboratorio, polvos vegetales provenientes de nueve especias condimentarias para el control de S. zeamais en concentraciones de 0,5; 1; 2 y 4%. Las variables evaluadas fueron mortalidad y emergencia (F1) de adultos y p\ue9rdida de peso y germinaci\uf3n del grano. Tambi\ue9n se evalu\uf3 el efecto repelente y fumigante a las concentraciones de 0,5; 1 y 2%. El dise\uf1o experimental fue completamente al azar, los tratamientos tuvieron cuatro repeticiones y el grupo de tratamientos fue repetido tres veces. Las mayores mortalidades se obtuvieron con Piper nigrum L. a 1% (83,4%), 2% (97,6%) y 4% (100%). Las menores emergencias de insectos adultos se obtuvieron en los mismos tratamientos m\ue1s Capsicum annuum var. Longum Sendtn., Cinnamomum zeylanicum Blime y Pimpinella anisum L. al 4% (p/p). La p\ue9rdida de peso y germinaci\uf3n de granos no registraron diferencia significativa. Todos los polvos vegetales fueron repelentes para Sitophilus zeamais y ninguno tuvo efecto fumigante

    Susceptibilidad de Tetranychus urticae Koch (Acari: Tetranychidae) colectada en Primula obconica Hance Y Convolvulus arvensis L. a acaricidas

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    The use of acaricides of high toxicity in the production and handling of ornamental plants should bea matter of consumer concern. The susceptibility of two populations of Tetranychus urticae was assessed: one collected from Primula obconica Hance and the other from Convolvulus arvenis L. as susceptible reference strain to the acaricides dicofol, abamectin alone and mixed with the surfactant phosphatidylcholine, azadirachtin, sulfur, pyridaben and fenazaquin. The evaluated parameters were mortality, lethal concentration 50% (LC50) and 90% (LC90), lethal time 50% (LT50) and 90% (LT90), effectiveness and index of resistance (IR). The experimental design was completely at random. Each treatment had \ubc, \ubd, 1, 2 and 4X of the doses indicated by the manufacturer, five replicates and were sprayed with a Potter spray tower. The results showed that the LC50 for azadirachtin and sulfur was significantly high. Regarding the population from P. obconica, abamectin alone and in mixture with phosphatidylcholine and fenazaquin showed the highest efficiency. Azadirachtin and sulfur were the acaricides showing the slowest activity and the resistance index indicated that the population collected in P. obconica should be considered susceptible to all the evaluated acaricides.El uso de acaricidas de alta toxicidad en la producci\uf3n y manejo de plantas ornamentales es un tema que deber\ueda preocupar a los consumidores. Se evalu\uf3 la susceptibilidad en laboratorio de dos poblaciones de Tetranychus urticae colectadas una en Primula obconica Hance y la otra en Convolvulus arvenis L, que se us\uf3 como raza sensible de referencia, a dicofol, abamectina, sola y en mezcla con el surfactante fosfatidilcolina, azadirachtina, azufre, pyridaben y fenazaquin. Las variables evaluadas fueron mortalidad, concentraci\uf3n letal 50% (CL50) y 90% (CL90), tiempo letal 50% (TL50) y 90% (TL90), eficacia e \uedndice de resistencia (IR). El dise\ue3o experimental fue completamente al azar. Cada acaricida se evalu\uf3 en \ubc, \ubd, 1, 2 y 4 veces la dosis recomendada seg\ufan el fabricante, y cada tratamiento tuvo cinco repeticiones y se aplicaron con una torre de Potter. Los resultados muestran que para azadirachtina y azufre la CL50 fue mayor. En la poblaci\uf3n proveniente de P. obconica, abamectina sola y en mezcla con fosfatidilcolina y fenazaquin propiciaron la mayor eficiencia. Azadirachtina y azufre demostraron ser los acaricidas de m\ue1s lenta acci\uf3n y el \uedndice de resistencia indica que la poblaci\uf3n colectada en P. obconica debe ser considerada como sensible a todos los acaricidas evaluados

    Susceptibilidad de Tetranychus urticae Koch (Acari: Tetranychidae) colectada en Primula obconica Hance Y Convolvulus arvensis L. a acaricidas

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    The use of acaricides of high toxicity in the production and handling of ornamental plants should bea matter of consumer concern. The susceptibility of two populations of Tetranychus urticae was assessed: one collected from Primula obconica Hance and the other from Convolvulus arvenis L. as susceptible reference strain to the acaricides dicofol, abamectin alone and mixed with the surfactant phosphatidylcholine, azadirachtin, sulfur, pyridaben and fenazaquin. The evaluated parameters were mortality, lethal concentration 50% (LC50) and 90% (LC90), lethal time 50% (LT50) and 90% (LT90), effectiveness and index of resistance (IR). The experimental design was completely at random. Each treatment had ¼, ½, 1, 2 and 4X of the doses indicated by the manufacturer, five replicates and were sprayed with a Potter spray tower. The results showed that the LC50 for azadirachtin and sulfur was significantly high. Regarding the population from P. obconica, abamectin alone and in mixture with phosphatidylcholine and fenazaquin showed the highest efficiency. Azadirachtin and sulfur were the acaricides showing the slowest activity and the resistance index indicated that the population collected in P. obconica should be considered susceptible to all the evaluated acaricides.El uso de acaricidas de alta toxicidad en la producción y manejo de plantas ornamentales es un tema que debería preocupar a los consumidores. Se evaluó la susceptibilidad en laboratorio de dos poblaciones de Tetranychus urticae colectadas una en Primula obconica Hance y la otra en Convolvulus arvenis L, que se usó como raza sensible de referencia, a dicofol, abamectina, sola y en mezcla con el surfactante fosfatidilcolina, azadirachtina, azufre, pyridaben y fenazaquin. Las variables evaluadas fueron mortalidad, concentración letal 50% (CL50) y 90% (CL90), tiempo letal 50% (TL50) y 90% (TL90), eficacia e índice de resistencia (IR). El diseão experimental fue completamente al azar. Cada acaricida se evaluó en ¼, ½, 1, 2 y 4 veces la dosis recomendada según el fabricante, y cada tratamiento tuvo cinco repeticiones y se aplicaron con una torre de Potter. Los resultados muestran que para azadirachtina y azufre la CL50 fue mayor. En la población proveniente de P. obconica, abamectina sola y en mezcla con fosfatidilcolina y fenazaquin propiciaron la mayor eficiencia. Azadirachtina y azufre demostraron ser los acaricidas de más lenta acción y el índice de resistencia indica que la población colectada en P. obconica debe ser considerada como sensible a todos los acaricidas evaluados

    Polvos de especias aromáticas para el control del gorgojo del maiz, Sitophilus zeamais Motschulsky, en trigo almacenado

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    The maize weevil, Sitophilus zeamais Motschulsky, is considered one of the most important pests of stored grains. Plant powders from nine seasoning spices were tested in the laboratory to control S. zeamais at 0,5, 1, 2 and 4% (w/w). The variables evaluated were mortality and emergence (F1) of adult insects, grain weight loss and grain germination. The repellent and fumigant effects were evaluated at concentrations of 0.5, 1, 2 and 4%; the experimental design was completely randomized, with four replicates, and the group of treatments was repeated three times. The highest mortality percentages were obtained with Piper nigrum L. at 1% (83.4%), 2% (97.6%) and 4% (100%). The lowest adult insect emergence was obtained with the same treatments more Capsicum annuum var. longum Sendtn., Cinnamomum zeylanicum Blume and Pimpinella anisum L. at 4% (w/w). No significant differences were recorded as regards grain weight loss and germination. All the plant powders tested had a repellent effect on Sitophilus zeamais and no fumigant effect was recorded.El gorgojo del maíz Sitophilus zeamais Motschulsky,es considerado una de las plagas mas importantes de productos almacenados. Se evaluaron, en laboratorio, polvos vegetales provenientes de nueve especias condimentarias para el control de S. zeamais en concentraciones de 0,5; 1; 2 y 4%. Las variables evaluadas fueron mortalidad y emergencia (F1) de adultos y pérdida de peso y germinación del grano. También se evaluó el efecto repelente y fumigante a las concentraciones de 0,5; 1 y 2%. El diseño experimental fue completamente al azar, los tratamientos tuvieron cuatro repeticiones y el grupo de tratamientos fue repetido tres veces. Las mayores mortalidades se obtuvieron con Piper nigrum L. a 1% (83,4%), 2% (97,6%) y 4% (100%). Las menores emergencias de insectos adultos se obtuvieron en los mismos tratamientos más Capsicum annuum var. Longum Sendtn., Cinnamomum zeylanicum Blime y Pimpinella anisum L. al 4% (p/p). La pérdida de peso y germinación de granos no registraron diferencia significativa. Todos los polvos vegetales fueron repelentes para Sitophilus zeamais y ninguno tuvo efecto fumigante

    Toxicity of Boldo Peumus boldus Molina for Sitophilus zeamais Motschulsky and Tribolium castaneum Herbst

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    The maize weevil (Sitophilus zeamais Motschulsky) and the red flour beetle (Tribolium castaneum Herbst) are two key pests of stored-grain products worldwide. The insecticidal activity of boldo (Peumus boldus Molina) powder, liquid ethanolic and hexanic extracts against S. zeamais and T. castaneum were evaluated under laboratory conditions. The evaluated variables were mortality, emergence of adult insects (F1), and grain weight loss. The experimental design was completely randomized. The mortality in S. zeamais was 100% even at the lowest powder concentration (0.5% w/w), whereas emergence of F1 adult insects was 0% and grain weight loss was ≤ 0.08%. For T. castaneum, only 8 and 16% w/w powder concentrations reached 100% mortality. The liquid ethanolic and hexanic extracts caused 100% mortality of S. zeamais, whereas only the ethanolic extract reached this value for T. castaneum. Therefore, the powder and the evaluated extracts of P. boldus were toxic for S. zeamais and T. castaneum and are promising against these and other stored-grain pests.El gorgojo del maíz (Sitophilus zeamais Motschulsky) y el escarabajo de la harina roja (Tribolium castaneum Herbst) son dos plagas clave de los productos de grano almacenado en todo el mundo. Se evaluó la actividad insecticida del polvo de boldo (Peumus boldus Molina), extractos etanólicos líquidos y hexánicos contra S. zeamais y T. castaneum en condiciones de laboratorio. Las variables evaluadas fueron la mortalidad, la aparición de insectos adultos (F1) y la pérdida de peso de los granos. El diseño experimental fue completamente al azar. La mortalidad en S. zeamais fue de 100% incluso a la concentración de polvo más baja (0,5% p / p), mientras que la aparición de insectos adultos F1 fue del 0% y la pérdida de peso del grano fue ≤ 0,08%. Para T. castaneum, solo 8 y 16% p / p de concentraciones de polvo alcanzaron una mortalidad del 100%. Los extractos etanólicos y hexánicos líquidos causaron 100% de mortalidad de S. zeamais, mientras que sólo el extracto etanólico alcanzó este valor para T. castaneum. Por lo tanto, el polvo y los extractos evaluados de P. boldus fueron tóxicos para S. zeamais y T. castaneum y son prometedores contra estas y otras plagas de grano almacenado

    TOXICITY OF BOLDO Peumus boldus MOLINA FOR Sitophilus zeamais MOTSCHULSKY AND Tribolium castaneum HERBST

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    The maize weevil ( Sitophilus zeamais Motschulsky) and the red flour beetle ( Tribolium castaneum Herbst) are two key pests of stored-grain products worldwide. The insecticidal activity of boldo ( Peumus boldus Molina) powder, liquid ethanolic and hexanic extracts against S. zeamais and T. castaneum were evaluated under laboratory conditions. The evaluated variables were mortality, emergence of adult insects (F1), and grain weight loss. The experimental design was completely randomized. The mortality in S. zeamais was 100% even at the lowest powder concentration (0.5% w/w), whereas emergence of F1 adult insects was 0% and grain weight loss was = 0.08%. For T. castaneum, only 8 and 16% w/w powder concentrations reached 100% mortality. The liquid ethanolic and hexanic extracts caused 100% mortality of S. zeamais, whereas only the ethanolic extract reached this value for T. castaneum. Therefore, the powder and the evaluated extracts of P. boldus were toxic for S. zeamais and T. castaneum and are promising against these and other stored-grain pests

    Actividad insecticida de Melia azedarach L. (Meliaceae) sobre Sitophilus Zeamais Motshulsky (Coleoptera:Curculionidae)

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    Maize weevil (SitophiluszeamaisMotschulsky) is considered worldwide as a primary pest of stored products, and its control is usually carried out with synthetic insecticides. The insecticidal and repellent properties of woody leaves, fruits and stems of Meliaazedarach L. (Meliaceae) were evaluated in laboratory conditions in concentrations of 0.5; 1.0 and 2.0% (w / w) for the control of S. zeamais. The highest mortality, as contact insecticide, was obtained with leaf dust and fruits at 2% with 91% mortality. No significant fumigant activity was observed, since no treatment exceeded 30% mortality. The powders of the three plant structures showed repellent effect, although the greater activity was observed in leaf dust. Finally, the dust of woody stalks affected the germination of the wheat. The M. azedarach powder presents auspicious prospects for the control of S. zeamais.El gorgojo del maíz (SitophiluszeamaisMotschulsky) es considerado a nivel mundial como plaga primaria de los productos almacenados, y su control normalmente se realiza con insecticidas sintéticos. Se evaluó en condiciones de laboratorio las propiedades insecticidas y repelentes del polvo de hojas, frutos y tallos leñosos de Meliaazedarach L. (Meliaceae) en concentraciones de 0,5; 1,0 y 2,0% (p/p) para el control de S. zeamais. La mayor mortalidad, como insecticida de contacto, se obtuvo con el polvo de hojas y frutos al 2% con 91% de mortalidad. No se observó actividad significativa como fumigante, ya que ningún tratamiento superó el 30% de mortalidad. Los polvos de las tres estructuras vegetales mostraron efecto repelente, aunque la mayor actividad se observó en el polvo de hojas. Finalmente, el polvo de tallos leñosos afectó la germinación del trigo. El polvo de M. azedarach presenta perspectivas auspiciosas para el control de S. zeamais

    ACEITE ESENCIAL DE FOLLAJE DE Peumus boldus Molina COLECTADO EN OTOÑO PARA EL CONTROL DE GORGOJO DEL MAÍZ Sitophilus zeamais Motschulsky

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    Maize weevil (Sitophilus zeamais Motschulsky) is one of the major pests of stored grains worldwide. Contact and fumigant toxicity, as well as repellent effects of essential oil from leaves of Peumus boldus Molina were tested in the laboratory against maize weevil. Leaves of Peumus boldus Molina were collected in autumn. The highest contact toxicity activity was obtained in concentrations of 2.0 and 4.0% (v/w) with 80 and 100% of mortality in the treated surface bioassay, and 81.1 and 100% in treated grain tests, respectively. In the bioassay of fumigant toxicity, the treatments of 30 and 35 µL essential oil 0.15 L-1 air showed 92.5 and 100% of dead insects. In the immature stage control bioassay, adult insect emergence (F1 ) in control was observed from week six, while treatments of 2.0 and 4.0% (v/w) of essential oil inhibited insect emergence in 100%. All the treatments assessed were repellents against adults of S. zeamais and maize germination was not affected when grains were mixed with essential oil. The essential oil of P. boldus has potential to be developed as a natural insecticide to control S. zeamais.El gorgojo del maíz (Sitophilus zeamais Motschulsky) es una de las plagas de los granos almacenados más importantes a nivel mundial. Se evaluó en condiciones de laboratorio la toxicidad como insecticida de contacto, fumigante y repelente del aceite esencial de hojas de Peumus boldus Molina, colectadas en otoño, para el control de S. zeamais. La mayor toxicidad por contacto se obtuvo con las concentraciones de 2,0 y 4,0% (v/p) con 80 y 100% de mortalidad en el bioensayo con una superficie tratada, y 81,1 y 100%, respectivamente, en las pruebas con grano tratado. En el bioensayo de toxicidad por efecto fumigante los tratamientos de 30 y 35 µL aceite esencial 0,15 L-1 aire mostraron 92,5 y 100% de insectos muertos. En el control de estados inmaduros, la emergencia (F1 ) de insectos adultos en el testigo se observó a partir de la semana seis mientras que los tratamientos de 2,0 y 4,0% (v/p) de aceite esencial inhibieron la emergencia en un 100%. Todos los tratamientos evaluados fueron repelentes contra adultos de S. zeamais y la germinación del maíz no se vio afectada al mezclar el grano con el aceite esencial. El aceite esencial de P. boldus tiene potencial para ser desarrollado como insecticida natural para el control de S. zemais

    Deep Underground Neutrino Experiment (DUNE) Near Detector Conceptual Design Report

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    International audienceThe Deep Underground Neutrino Experiment (DUNE) is an international, world-class experiment aimed at exploring fundamental questions about the universe that are at the forefront of astrophysics and particle physics research. DUNE will study questions pertaining to the preponderance of matter over antimatter in the early universe, the dynamics of supernovae, the subtleties of neutrino interaction physics, and a number of beyond the Standard Model topics accessible in a powerful neutrino beam. A critical component of the DUNE physics program involves the study of changes in a powerful beam of neutrinos, i.e., neutrino oscillations, as the neutrinos propagate a long distance. The experiment consists of a near detector, sited close to the source of the beam, and a far detector, sited along the beam at a large distance. This document, the DUNE Near Detector Conceptual Design Report (CDR), describes the design of the DUNE near detector and the science program that drives the design and technology choices. The goals and requirements underlying the design, along with projected performance are given. It serves as a starting point for a more detailed design that will be described in future documents

    Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC

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    DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6 ×\times  6 ×\times  6 m3^3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019–2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6x6x6m3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties
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