| 1. |
- Lindelöw, Åke, et al.
(author)
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Svart granbastborre
- 2017
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In: Skogsskötselserien. ; , s. 65-68
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Other publication (pop. science, debate, etc.)abstract
- Svart granbastborre har en liknande biologi som snytbaggen och arterna förekommer ofta tillsammans. Planterade granplantor skadas genom de fullbildade bastborrarnas gnag i barken på rötter och nedersta delen av stammen. Märkligt nog har i Sverige inga mer omfattande plantskador förorsakade av den lika allmänna svarta tallbastborren noterats i tallplanteringar.
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| 2. |
- Nordlander, Göran, et al.
(author)
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Influence of climate and forest management on damage risk by the pine weevil Hylobius abietis in northern Sweden
- 2017
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In: Silva Fennica. - : Finnish Society of Forest Science. - 0037-5330 .- 2242-4075. ; 51
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Journal article (peer-reviewed)abstract
- The pine weevil Hylobius abietis L. is an economically important pest insect that kills high proportions of conifer seedlings in reforestation areas. It is present in conifer forests all over Europe but weevil abundance and risk for damage varies considerably between areas. This study aimed to obtain a useful model for predicting damage risks by analyzing survey data from 292 regular forest plantations in northern Sweden. A model of pine weevil attack was constructed using various site characteristics, including both climatic factors and factors related to forest management activities. The optimal model was rather imprecise but showed that the risk of pine weevil attack can be predicted approximatively with three principal variables: 1) the proportion of seedlings expected to be planted in mineral soil rather than soil covered with duff and debris, 2) age of clear-cut at the time of planting, and 3) calculated temperature sum at the location. The model was constructed using long-run average temperature sums for epoch 2010, and so effects of climate change can be inferred from the model by adjustment to future epochs. Increased damage risks with a warmer climate are strongly indicated by the model. Effects of a warmer climate on the geographical distribution and abundance of the pine weevil are also discussed. The new tool to better estimate the risk of damage should provide a basis for foresters in their choice of countermeasures against pine weevil damage in northern Europe.
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| 3. |
- Nordlander, Göran, et al.
(author)
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Replanting conifer seedlings after pine weevil emigration in spring decreases feeding damage and seedling mortality
- 2017
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In: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 32, s. 60-67
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Journal article (peer-reviewed)abstract
- Replanting at appropriate times after harvesting a coniferous forest stand can help efforts to suppress seedling mortality caused by the pine weevil Hylobius abietis, but optimal times are uncertain. We hypothesized that planting in June rather than May in the third season after harvest would reduce feeding damage by the pine weevil and increase seedling survival rates in central Sweden, where new-generation weevils mainly fly away from their development sites in May/early June. An experimental test of the hypothesis in eight clear-cuts confirmed that planting in June instead of May reduced proportions of seedlings attacked by pine weevil, bark removal from seedlings' stems, and proportions of seedlings killed by feeding damage. These differences between seedlings planted in May and June declined to some extent with time but still remained significant after two growing seasons. The total seedling mortality after two seasons did, however, not differ significantly between seedlings planted in May and June. Overall, 29% of all seedlings were killed by pine weevil, 4.0% by Hylastes bark beetles, and 2.3% by drought. The results indicate that replanting in spring during the third season after harvest can advantageously continue until mid-June with respect to damage and mortality.
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| 4. |
- Nordlander, Göran, et al.
(author)
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Snytbaggen
- 2017
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In: Skogsskötselserien. ; , s. 46-64
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Other publication (pop. science, debate, etc.)abstract
- Snytbaggen gnager av barken på barrträdsplantor men även på tunnare grenar och rötter av större barrträd. Nyplanterade plantor dödas i stor utsträckning genom att gnaget ringbarkar stammen. Omfattande skador av snytbagge har varit ett konstant problem sedan övergången till trakthyggesbruk. Dagens skogsbruk med nya hyggen varje år relativt jämnt fördelade i landskapet ger förutsättningen för en stabilt hög populationsnivå hos snytbaggen. Skadorna som snytbaggen orsakar kostar det svenska skogsbruket hundratals miljoner kronor årligen.
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| 5. |
- Zas, Rafael, et al.
(author)
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Genetic variation in resistance of Norway spruce seedlings to damage by the pine weevil Hylobius abietis
- 2017
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In: Tree Genetics & Genomes. - : Springer Berlin/Heidelberg. - 1614-2942 .- 1614-2950. ; 13:5
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Journal article (peer-reviewed)abstract
- Regeneration of northern conifer forests is commonly performed by reforestation with genetically improved materials obtained from long-term breeding programs focused on productivity and timber quality. Sanitary threats can, however, compromise the realization of the expected genetic gain. Including pest resistance traits in the breeding programs may contribute to a sustainable protection. Here we quantified the variation in different components of resistance of Norway spruce to its main pest, the pine weevil Hylobius abietis. We followed insect damage in two large progeny trials (52 open-pollinated families with 100-200 individuals per family and trial) naturally infested by the pine weevil. Pine weevils damaged between 17 and 48% of the planted seedlings depending on the trial and year, and mortality due to weevil damage was up to 11.4%. The results indicate significant genetic variation in resistance to the pine weevil, and importantly, the variation was highly consistent across trials irrespective of contrasting incidence levels. Individual heritability estimates for the different components of seedling resistance were consistently low, but family heritabilities were moderate (0.53 to 0.81). While forward selections and breeding for higher resistance seem not feasible, backwards selections of the best parent trees emerge as a putative alternative to reduce weevil damage. A positive genetic correlation between early growth potential and probability of being attacked by the weevil was also observed, but the relationship was weak and appeared only in one of the trials. Overall, results presented here open the door to a new attractive way for reducing damage caused by this harmful pest.
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