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.
2013
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Authors
Tobias Bidon Christiane Frosch Hans Geir Eiken Verena E. Kutschera Snorre Hagen Siv Aarnes Steven R. Fain Axel Janke Frank HailerAbstract
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Authors
Ole Petter Laksforsmo Vindstad Tino Schott Snorre Hagen Jane Uhd Jepsen Lauri Teemu Kapari Rolf Anker ImsAbstract
Two related issues in studies of biological invasions are how quickly the enemy complexes of invasive species become as species-rich and efficient as those of native species and how important enemy release is for the establishment and spread of invaders. We addressed these issues for the geometrid moths Operophtera brumata and Agriopis aurantiaria, who invaded the coastal mountain birch forest of northern Norway by range expansion approximately a century and 15 years ago, respectively. This was done by comparing larval parasitoid species richness and prevalence among the invaders and the native geometrid Epirrita autumnata. We found that E. autumnata and O. brumata both hosted seven parasitoid species groups, whereas A. aurantiaria hosted only one. Several parasitoid groups were shared between two or more of the geometrids. Total larval parasitism rates were similar in all three geometrid species, and comparison with published studies on larval parasitism in Western Europe suggested that O. brumata and A. aurantiaria do not suffer lower parasitism rates in our study region than in their native ranges. Our results indicate that accumulation of larval parasitoids on invasive geometrids in coastal mountain birch forest may reach completion within a few decades to at least a century after the invasion, and that establishment and spread of such invaders is unlikely to be facilitated by release from larval parasitism. Our investigations also uncovered a high degree of spatiotemporal synchrony between the total larval parasitism rates of O. brumata and A. aurantiaria, suggesting that larval parasitism of different geometrid species in the study system is governed by some common external factor
Authors
Tino Schott Lauri Teemu Kapari Snorre Hagen Ole Petter Laksforsmo Vindstad Jane Uhd Jepsen Rolf Anker ImsAbstract
Outbreaks of geometrid defoliators in subarctic birch forest in Fennoscandia often occur at high altitude in a distinct zone along the tree line. At the same time, moth larvae may not have an impact on the forest at lower altitude. Directly adjacent outbreak and nonoutbreak areas offer unique opportunities for studying the underlying mechanisms of outbreaks. Within two altitudinal gradients in coastal northern Norway, we investigated whether altitudinal outbreaks might be caused by release from pupal predation by ground-dwelling invertebrates such as harvestmen (Opiliones), spiders (Araneae), rove beetles (Coleoptera: Staphylinidae), carabid beetles (Coleoptera: Carabidae), and other beetles (Coleoptera). We predicted a consistently higher abundance of such generalist predators at low versus high altitudes. Our results did not support this prediction. There was no consistent altitudinal variation in the abundance of predators that could be related to zonal moth outbreaks in the birch forest slopes. In addition, none of the predator groups investigated showed any numerical response to a distinct outbreak of winter moth that took place during the course of the study. Consequently, localised moth outbreaks at the altitudinal tree line in northern Norway cannot be explained by the release from pupal predation by the predator groups examined here.
Authors
I.N Bolotov A.A Makhrov Yu. V. Bespalaya I.V. Vikhrev O.V. Aksenova Paul Eric Aspholm M. Yu Gofarov A.N: Ostrovskii I. Yu. Popov I. S. Pal'tser M. Rudzite M. Rudzitis I. S. Voroshilova S.E. SokolovaAbstract
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Authors
Panu Oulasvirta Paul Eric Aspholm Marko Kangas Bjørn Mejdell Larsen Pirko-Lisa Luhta P. Olofsson J. TaskinenAbstract
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2012
Authors
Alexander Kopatz Hans Geir Eiken Snorre Hagen Minna Ruokonen Rodrigo Esparza-Salas Julia Schregel Ilpo Kojala Martin Smith Ingvild Wartiainen Paul Eric Aspholm Steinar Wikan Alexander M. Rykov Olga Makarova Natalia Polikarpova Konstantin F. Tirronen Pjotr I. Danilov Jouni AspiAbstract
No abstract has been registered