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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.

2018

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Abstract

The sentinel plants concept responds to the need for new strategies to identify and study potential plant pests (including pathogens) and assess associated risks before their introduction to other continents. However, even if very promising, this tool is not yet implemented on a large scale, partially because it requires adequate planning, long-term funding, strong local links and reliable collaborators. In addition, a wider implementation of sentinel plantations and sentinel nurseries requires knowledge of regulations and procedures regarding the possibilities for their establishment in different countries. In order to achieve this objective, a questionnaire survey was conducted in 2016, to which more than 40 countries around the world responded. The results reveal that many countries have few regulations specifically concerning the import of propagation material, making import of this relatively low-risk material easier than the import of larger living plants that may have been more exposed to pests in the exporting country. The planting of alien woody plants in the environment is possible for scientific purposes in most countries as exemption from general phytosanitary import requirements, but the import and planting of alien plant species may be regulated by different government departments. We will present the outcomes of this study, which will be useful to facilitate the selection of locations for future sentinel plants and may provide guidance on the rules for import of plant propagation material for the establishment of sentinel plants and sentinel nurseries in different countries.

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Abstract

Recently, Deutsch and colleagues(1) projected future increases in yield losses to insect pests of the three globally most important staple crops under different climate change scenarios. Their results are based on model simulations parameterized with thermal sensitivity analyses of population growth and metabolic rates from a geographically and functionally diverse set of insect species taken from an earlier study(2). A subset of the original data compilation was then used to estimate the direct impact of warming on insect fitness across latitudes(3). More precisely, the derived thermal-dependence of fitness for globally distributed terrestrial insect species was integrated with projected geographic distribution of climate change for the next century (3). These models were then deployed in the new study investigating potential yield losses in three specific crops(1). We submit that Deutsch and colleagues rely on inadequate empirical data for their model parameterization to estimate pest-related crop losses. Strikingly, their source data did not include major pest taxa of the focal staple crops and were not restricted to herbivores despite that temperature-dependence of metabolic and performance responses are known to vary substantially among trophic levels and functional groups(4,5). Hence, the inferences drawn by Deutsch and colleagues(1) may be unreliable. Mitigating potential climate change responses of pest organisms jeopardizing future food security can only be successful if they are based on high-quality information relevant to the crop system in question(6). References 1. C. A. Deutsch et al., Science. 361, 916–919 (2018). 2. M. R. Frazier, R. B. Huey, D. Berrigan, Am. Nat. 168, 512–520 (2006). 3. C. A. Deutsch et al., Proc. Natl. Acad. Sci. 105, 6668–6672 (2008). 4. A. I. Dell, S. Pawar, V. M. Savage, Proc. Natl. Acad. Sci. 108, 10591–10596 (2011). 5. A. I. Dell, S. Pawar, V. M. Savage, J. Anim. Ecol. 83, 70–84 (2014). 6. P. Lehmann et al., bioRxiv (2018), doi:10.1101/425488.

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Abstract

A warmer climate may potentially have a strong effect on the health status of European oak forests by weakening oak trees and facilitating mass reproduction of wood boring insects. We did a laboratory experiment in Slovakia to study the response of major pest beetles of oak and their parasitoids to different temperature regimes as background for predicting climatic effects and improving management tools of European oak forests. With higher temperatures the most important oak pest Scolytus intricatus emerged much earlier, which indicate that completion of a second generation and increased damage further north in European oak forests may be possible. Lower temperatures gave longer larval galleries and more offspring per parents but still lower beetle production due to semivoltine life cycle. For buprestids and longhorn beetles warmer temperatures resulted in more emerging offspring and a shift towards earlier emergence in the same season, but no emergence in the first season indicated that a change to univoltine populations is not likely. Reduced development success of parasitoids at the highest temperatures (25/30 °C) indicates a loss of population regulation for pest beetle populations. A warmer climate may lead to invasion of other population-regulating parasitoids, but also new serious pest may invade. With expected temperature increases it is recommended to use trap trees both in April and in June, and trap trees should be removed within 2 months instead 1 year as described in the current standard.

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Abstract

In temperate forests, red wood ants (Formica aquilonia) are considered ecosystem engineers affecting ecosystem properties and functions. Possible effects of F. aquilonia ants on species communities of invertebrates and plants were studied in the pine-dominated Geitaknottane forest reserve, Norway. Species richness of carabids, lichens and epiphytes (tree-living lichens and bryophytes) was negatively affected by ant mound density. Species of all groups, except for lichens and snails, were affected either positively or negatively by ant presence. Food availability and interference competition are plausible explanations of decreased species richness and negative species associations in carabids; while collecting, foraging and changed chemical environment may explain decreased species richness in lichens and epiphytes. Thirteen out of 15 plant and invertebrate species were weakly associated with ant mound density. Associations of only two species (Carabus violaceus and Drusilla canaliculata) were negative, while Pella humeralis and Agroeca proxima were associated positively and very strongly with ant mounds. Positive associations with ants of those invertebrates may be a response to excessive abundance of food and chemical mimicry.