81 research outputs found

    Toelating neo's en bijensterfte zijn twee vraagstukken

    Get PDF
    In de media worden 'bijensterfte'en 'toelating en gebruik van neonicotinoïde gewasbeschermingsmiddelen' als één vraagstuk gepresenteerd. De auteur maakt duidelijk dat het er twee zijn

    Bijen en maisstuifmeel

    Get PDF
    In Nederland wordt heel wat (voeder)mais geteeld, evenals in grote delen van de rest van Europa, vooral in landen die ook veel bijenvolken hebben. Hoewel deze plant een windbestuiver is, wordt het stuifmeel wel door honingbijen verzameld. Hoe goed of slecht is dat eigenlijk? Wat is hierover uit onderzoek bekend

    Hoeveel stuifmeel zit er in honing?

    Get PDF
    In honing zit altijd wat stuifmeel (en ook wat nectar in het bijenbrood). Bijen@wur zocht uit; "Hoeveel dan?

    Oxaalzuuralternatief voor in de zomer

    Get PDF
    Waar varroabestrijden 20 jaar geleden iets was wat je als bijenhouder erbij deed, is het nu een belangrijk deel van de bedrijfsvoering. Als er geen gesloten broed is, is oxaalzuur een effectief middel tegen varroamijten. Zo effectief dat sommige professionele imkers niets anders gebruiken. Maar kleinere bijenhouders bezorgt het inpassen van bestrijdingsmethoden in hun bedrijfsvoering wel eens hoofdbrekens. De hier beschreven methode biedt misschien een oplossing

    Colour response in western flower thrips varies intraspecifically

    Get PDF
    Discrepancies in the published research as to the attraction of the economically important pest western flower thrips (WFT) to different colours confounds the optimisation of field traps for pest management purposes. We considered whether the different experimental conditions of independent studies could have contributed to this. Therefore, the behavioural response (i.e., landings) to different colour cues of two WFT laboratory populations from Germany (DE) and The Netherlands (NL), which had previously been independently shown to have different colour preferences, were tested in the same place, and under the same experimental conditions. Single-choice wind tunnel bioassays supported previous independent findings, with more of a NL population landing on the yellow LED lamp (588 nm) than the blue (470 nm) (p = 0.022), and a not-statistically significant trend observed in a DE population landing more on blue compared to yellow (p = 0.104). To account for potential original host rearing influences, both populations were subsequently established on bean for ~20 weeks, then yellow chrysanthemum for 4–8 and 12–14 weeks and tested in wind tunnel choice bioassays. Laboratory of origin, irrespective of the host plant rearing regime, remained a significant effect (p < 0.001), with 65% of the NL WFT landing on yellow compared to blue (35%), while 66% of the DE WFT landed on blue compared to yellow (34%). There was also a significant host plant effect (p < 0.001), with increased response to yellow independent of laboratory of origin after rearing on chrysanthemum for 12–14 weeks. Results suggest that differing responses of WFT populations to colour is, in this case, independent of the experimental situation. Long-term separate isolation from the wild cannot be excluded as a cause, and the implications of this for optimising the trap colour is discussed

    Spatially structured environmental filtering of collembolan traits in late successional salt marsh vegetation

    Get PDF
    Both the environment and the spatial configuration of habitat patches are important factors that shape community composition and affect species diversity patterns. Species have traits that allow them to respond to their environment. Our current knowledge on environment to species traits relationships is limited in spite of its potential importance for understanding community assembly and ecosystem function. The aim of our study was to examine the relative roles of environmental and spatial variables for the small-scale variation in Collembola (springtail) communities in a Dutch salt marsh. We used a trait-based approach in combination with spatial statistics and variance partitioning, between environmental and spatial variables, to examine the important ecological factors that drive community composition. Turnover of trait diversity across space was lower than for species diversity. Most of the variation in community composition was explained by small-scale spatial variation in topography, on a scale of 4-6 m, most likely because it determines the effect of inundation, which restricts where habitat generalists can persist. There were only small pure spatial effects on species and trait diversity, indicating that biotic interactions or dispersal limitation probably were less important for structuring the community at this scale. Our results suggest that for springtails, life form (i.e. whether they live in the soil or litter or on the surface/in vegetation) is an important and useful trait to understand community assembly. Hence, using traits in addition to species identity when analysing environment-organism relationships results in a better understanding of the factors affecting community composition

    Estación Experimental de Aula Dei. Memoria anual 2014

    Get PDF
    67 Pags.Esta memoria recoge la actividad científica de la Estación Experimental de Aula Dei (EEAD-CSIC) durante el año 2014, conteniendo información específica sobre las siguientes actividades de la EEAD-CSIC: Publicaciones (ISI y no ISI; Actas de congresos; Libros y Capítulos de Libro), Transferencia tecnológica, Tesis, Congresos, Cursos, Seminarios, Estancias, Actividades de cultura científica, Eventos. Incluye, además, un informe de financiación, directorio del personal en activo durante el año y tabla-resumen de las estadísticas relacionadas con los procesos técnicos y servicios de la Unidad Técnica de Biblioteca y Documentación.Peer reviewe

    Weeds for bees? A review

    Full text link
    corecore