Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2012
Authors
Anders T Bråten Daniel Flø Sigmund Hågvar Oddvar Hanssen Christian Einar Mong Kjetil AakraAbstract
Spiders and beetles were pitfall-trapped in the foreland of the receding Hardangerjøkulen glacier in central south Norway. At each of six sampling sites, ages 3 to 205 years, twenty traps covered the local variation in moisture and plant communities. Thirty-three spider species and forty beetle species were collected. The species composition was correlated to time since glaciation and vegetation cover. A characteristic pioneer community of spiders and mainly predatory beetles had several open-ground species, and some species or genera were common to forelands in Svalbard or the Alps. While the number of spider species increased relatively constant with age, the number of beetle species seemed to level off after about 80 years. Half of the beetle species were Staphylinidae, and contrary to Carabidae, most of these were rather late colonizers. Most herbivore beetles colonized after more than 40 years, but the moss-eating Byrrhidae species Simplocaria metallica and also certain Chironomidae larvae developed in pioneer moss colonies after 4 years. The large Collembola Bourletiella hortensis, a potential prey, fed on in-blown moss fragments after 3 years. In the present foreland, chlorophyll-based food chains may start very early. Two pioneer Amara species (Carabidae) could probably feed partly on seeds, either in-blown or produced by scattered pioneer grasses.
Authors
Paal KrokeneAbstract
No abstract has been registered
Authors
M. Ashraful Islam Henrik Lütken Sissel Haugslien Sissel Torre Jorunn Elisabeth Olsen Dag-Ragnar Blystad Søren Rasmussen Jihong Liu ClarkeAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Jihong Liu ClarkeAbstract
No abstract has been registered
Authors
Ragnar TveteråsAbstract
No abstract has been registered
Authors
Simon WeldonAbstract
No abstract has been registered
Authors
Frans van den Berg A. Tiktak G. B. M. Heuvelink S. L. G. E. Burgers D. J. Brus F. de Vries Jannes Stolte J. G. KroesAbstract
No abstract has been registered
Abstract
Light-emitting diodes (LEDs), high-pressure sodium lamps (HPSLs) and some cladding materials offer possibilities of influencing arthropod integrated pest management in greenhouse crops where light quality, quantity and photoperiod differ from nature. Light intensity, photoperiod and wavelength distribution affect plant functions and quality which, in turn, can be reflected in the performance of herbivores. The attenuation of UV-light in HPSL spectrum and in the natural winter daylight of northern latitudes may make plants more vulnerable to pests, whereas the high ratio of red to far-red of HPSLs may act to compensate for the effects of attenuated UV-levels. High red to far red ratio has been shown to result in increased production of plant phenolics and physical defences such as leaf toughness, which, in turn, can negatively influence the performance of some herbivore guilds on plants. Specific spectra produced by LEDs can influence plant quality and hence herbivore performance, but direct effects on arthropods can be even more pronounced, such as the inability to visually locat host plants in red and blue lights. Other direct effects of artificial light on pests and beneficial organisms include the detrimental effect of UV-C and UV-B on arthropods, diapause prevention by species-specific wavelengths or photoperiods, attraction to yellow-green and polarized light, reduced visibility of host or prey, and changes in take-off behaviour. Other effects include response to light intensity, interactive effects of light quality and photoperiod on fecundity, and species-specific effects of continuous light on the population growth of arthropods and plant-infesting fungi as well as the rhythmic expression of xenobiotic metabolising genes in arthropods. The potential of using the knowledge of photobiology and visual ecology of organisms for plant protection are discussed using whiteflies and fungal diseases of plants as the model species.
Abstract
No abstract has been registered