55 research outputs found

    A new species and new record of Agistemus Summers (Acari: Stigmaeidae) associated with Capsicum annuum L. var. glabriusculum (Solanaceae) from Northeastern of Mexico

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    Two mite species belonging to the genus Agistemus Summers (Acari: Stigmaeidae) were collected from wild plants known as “chile piquín” (Capsicum anuumm L. var. glabriusculum) in two protected naturals areas, state of Tamaulipas, Mexico. Agistemus piquinnus Monjarás-Barrera & Johann n. sp. is described and illustrated. Agistemus brasiliensis Matioli, Ueckermann & Oliveira, 2002 is a new record for Mexico. A key to the Agistemus species of Mexico is provided

    Depredación de Pselliopus latispina (Hemiptera: Reduviidae) sobre Tetranychus urticae (Acari: Tetranychidae)

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    Se reporta la capacidad depredadora de Pselliopus latispina Hussey (Hemiptera: Reduviidae) sobre el ácaro de dos manchas Tetranychus urticae Koch (Acari: Tetranychidae), bajo condiciones de laboratorio. Se utilizaron ninfas de P. latispina de primer instar, provenientes de masas de huevos recolectadas en la Sierra de Álvarez, San Luis Potosí, sobre árboles de cedro blanco Juniperus flaccida Schltdl. (Cupressaceae) y hembras adultas de T. urticae desarrolladas en plantas de frijol Phaseolus vulgaris L. (Fabaceae), originadas a partir de recolectas en huertas de manzana Malus domestica Borkh. (Rosaceae) de Huachichil, Arteaga; Coahuila. Se colocaron ninfas individuales de P. latispina con 50 hembras adultas de T. urticae en cajas Petri, con la finalidad de observar el comportamiento depredador de las ninfas sobre el ácaro. Los datos de depredación fueron analizados con ANOVA y separación de medias mediante pruebas de rango múltiple de Tukey. Se observó la depredación a las 8, 16 y 24 horas y se contabilizó la mortalidad de ácaros. La depredación de P. latispina se incrementó proporcionalmente con el tiempo de exposición, con un consumo promedio de 20, 37 y 48 ácaros a las 8, 16 y 24 horas respectivamente, brindando una nueva opción de manejo del ácaro de dos manchas

    Efecto de concentraciones subletales de flufenoxuron sobre parámetros poblacionales de Tetranychus urticae Koch (Acari: Tetranychidae)

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    El flufenoxuron es un producto considerado como un regulador de crecimiento con efecto acaricida; sin embargo, se desconoce el grado de influencia que éste tiene en aspectos ecológicos inherente al incremento poblacional de Tetranychus urticae Koch. El objetivo del presente estudio fue determinar el efecto de concentraciones subletales de flufenoxuron en T. urticae utilizando como sustrato hojas de frijol. Para este propósito se eligieron las concentraciones de 17.7, 59.9 y 106.7 ppm de flufenoxuron. Mismas que en la línea de regresión concentración - mortalidad a 72 horas- correspondieron a la CL5, CL20 y CL40, respectivamente. La exposición de estos ácaros a concentraciones subletales indican como respuesta cambios significativos en algunos de los parámetros poblacionales, sobre todo en la tasa reproductiva bruta (TRB), tasa reproductiva neta (Ro), tiempo de duración de la cohorte (Tc) y tiempo de generación (TG)

    Respuesta funcional de Phytoseiulus persimilis sobre Oligonychus punicae (Acari: Phytoseiidae, Tetranychidae) en hojas de aguacate

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    Functional response of Phytoseiulus persimilis (Athias-Henriot, 1957) at different densities and developmental stages of the mite of Oligonychus punicae (Hirst, 1926) under laboratory conditions was evaluated. Results show no predation in the egg state, whereas for the other stages, the predator exhibited a type II functional response. Average consumption of P. persimilis over O. punicae was 23.4 and 14.67 for larvae and nymphs respectively at a density of 64 prey offered, while the maximum average consumption in adult females of O. punicae was 6.07 adults at a density of 16 female adults offered. The results of predation obtained, concluded that P. persimilis can be used as a biocontrol agentSe evaluó la respuesta funcional de Phytoseiulus persimilis (Athias-Henriot, 1957) sobre diferentes densidades y estados de desarrollo del ácaro del aguacate Oligonychus punicae (Hirst, 1926) bajo condiciones de laboratorio. Los resultados muestran nula depredación en el estado de huevo, mientras que para el resto de los estados, el depredador exhibió una respuesta funcional tipo II. El máximo consumo de P. persimilis sobre O. punicae fue en promedio de 23.4 y 14.67 para larvas y ninfas respectivamente a una densidad de 64 presas ofrecidas, mientras que el máximo promedio de consumo en hembras adultas de O. punicae fue de 6.07 adultos a una densidad de 16 adultos hembra ofrecidos. Los resultados de la depredación muestran que P. persimilis puede ser utilizado como un agente de control biológico

    Temporal and spatial segregation of top predators (Felidae) in a Mexican tropical Biosphere Reserve

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    Jaguars, Panthera onca (Linnaeus, 1758), and pumas, Puma concolor (Linnaeus, 1771) are the largest felids in the neotropics. Both can overlap in niche axes (time, space and prey), and are therefore potentially competing species. Segregation mechanisms presented by a low overlap in one of these axes of niche can facilitate the coexistence. Our aim was to analyze jaguar and puma temporal and spatial overlap for understanding their segregation mechanisms. Between 2015 and 2017, twenty-six camera trap stations were located in five habitat types of El Cielo Biosphere Reserve (ECBR) in northeastern Mexico. Temporal activity was analyzed using circular statistics and time overlap analysis. Spatial overlap was calculated with the Pianka index and a selectivity habitat analysis. Our results showed that jaguars and pumas were nocturnal and that the temporal overlap was high (∆4 = 0.77). We found an intermediate spatial overlap (Pianka index = 0.61). Jaguars were more selective and preferred the deciduous forest. In comparison, pumas preferred oak-pine forest, but also used oak and deciduous forest. Our results indicate that spatial segregation best explains the coexistence of jaguars and pumas in our study area, probably due to both habitat diversity in the reserve and the generalist habits of the puma

    Healthcare workers hospitalized due to COVID-19 have no higher risk of death than general population. Data from the Spanish SEMI-COVID-19 Registry

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    Aim To determine whether healthcare workers (HCW) hospitalized in Spain due to COVID-19 have a worse prognosis than non-healthcare workers (NHCW). Methods Observational cohort study based on the SEMI-COVID-19 Registry, a nationwide registry that collects sociodemographic, clinical, laboratory, and treatment data on patients hospitalised with COVID-19 in Spain. Patients aged 20-65 years were selected. A multivariate logistic regression model was performed to identify factors associated with mortality. Results As of 22 May 2020, 4393 patients were included, of whom 419 (9.5%) were HCW. Median (interquartile range) age of HCW was 52 (15) years and 62.4% were women. Prevalence of comorbidities and severe radiological findings upon admission were less frequent in HCW. There were no difference in need of respiratory support and admission to intensive care unit, but occurrence of sepsis and in-hospital mortality was lower in HCW (1.7% vs. 3.9%; p = 0.024 and 0.7% vs. 4.8%; p<0.001 respectively). Age, male sex and comorbidity, were independently associated with higher in-hospital mortality and healthcare working with lower mortality (OR 0.211, 95%CI 0.067-0.667, p = 0.008). 30-days survival was higher in HCW (0.968 vs. 0.851 p<0.001). Conclusions Hospitalized COVID-19 HCW had fewer comorbidities and a better prognosis than NHCW. Our results suggest that professional exposure to COVID-19 in HCW does not carry more clinical severity nor mortality

    Evolving trends in the management of acute appendicitis during COVID-19 waves. The ACIE appy II study

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    Background: In 2020, ACIE Appy study showed that COVID-19 pandemic heavily affected the management of patients with acute appendicitis (AA) worldwide, with an increased rate of non-operative management (NOM) strategies and a trend toward open surgery due to concern of virus transmission by laparoscopy and controversial recommendations on this issue. The aim of this study was to survey again the same group of surgeons to assess if any difference in management attitudes of AA had occurred in the later stages of the outbreak. Methods: From August 15 to September 30, 2021, an online questionnaire was sent to all 709 participants of the ACIE Appy study. The questionnaire included questions on personal protective equipment (PPE), local policies and screening for SARS-CoV-2 infection, NOM, surgical approach and disease presentations in 2021. The results were compared with the results from the previous study. Results: A total of 476 answers were collected (response rate 67.1%). Screening policies were significatively improved with most patients screened regardless of symptoms (89.5% vs. 37.4%) with PCR and antigenic test as the preferred test (74.1% vs. 26.3%). More patients tested positive before surgery and commercial systems were the preferred ones to filter smoke plumes during laparoscopy. Laparoscopic appendicectomy was the first option in the treatment of AA, with a declined use of NOM. Conclusion: Management of AA has improved in the last waves of pandemic. Increased evidence regarding SARS-COV-2 infection along with a timely healthcare systems response has been translated into tailored attitudes and a better care for patients with AA worldwide
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