scholarly journals Effects of Mounding on Damage by the European Pine Weevil in Planted Norway Spruce Seedlings

2005 ◽  
Vol 22 (3) ◽  
pp. 154-161 ◽  
Author(s):  
Juha Heiskanen ◽  
Heli Viiri
Keyword(s):  
Norway Spruce ◽  
Growing Season ◽  
Northern Europe ◽  
Hylobius Abietis ◽  
Seedling Mortality ◽  
Growth And Survival ◽  
Vegetation Control ◽  
Pine Weevil ◽  
Forest Sites ◽  
Major Pest

Abstract The European pine weevil (Hylobius abietis L.) is not found in northern America so far but is the major pest in conifer reforestation in northern Europe. The effects of mounding on pine-weevil damage and growth in planted Norway spruce (Picea abies (L.) Karst.) seedlings were studied on two clearcut forest sites in Finland. Three different mounding treatments (spot mounding with or without mixing and inverting) were compared to three unscarified treatments with or without vegetation control (mulch or herbicide). Mounding significantly decreased pine-weevil damage, mortality, and growth losses of planted Norway spruce seedlings even if insecticide was used before planting. Seedling growth and survival were poorest with the heaviest feeding by the pine weevil. After the first growing season, the proportion of gnawed seedlings was higher on unscarified spots (76% gnawed), whereas seedlings on mounded spots had hardly any feeding (1%). Seedling mortality was lower on mounded (1%) than on unscarified spots, where it was higher in 1-year-old (27%) than 2-year-old seedlings (10%). After the second growing season, mortality and proportion of gnawed seedlings increased on both mounded and unscarified spots. The study indicates that mounding can provide an effective method of decreasing pine-weevil damage and improving plantation success.North. J. Appl. For. 22(3):154 –161.

scholarly journals Gut microbiota of the pine weevil degrades conifer diterpenes and increases insect fitness

2017 ◽  
Author(s):  
Aileen Berasategui ◽  
Hassan Salem ◽  
Christian Paetz ◽  
Maricel Santoro ◽  
Jonathan Gershenzon ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Gut Microbiota ◽  
Norway Spruce ◽  
Antibiotic Treatment ◽  
Hatching Rate ◽  
Pine Weevil ◽  
Pine Weevils ◽  
Gut Symbionts ◽  
Major Pest ◽  
Insect Fitness

AbstractThe pine weevil (Hylobius abietis), a major pest of conifer forests throughout Europe, feeds on the bark and cambium, tissues rich in terpenoid resins that are toxic to many insect herbivores. Here we report the ability of the pine weevil gut microbiota to degrade the diterpene acids of Norway spruce. The diterpene acid levels present in ingested bark were substantially reduced on passage through the pine weevil gut. This reduction was significantly less upon antibiotic treatment, and supplementing the diet with gut suspensions from untreated insects restored the ability to degrade diterpenes. In addition, cultured bacteria isolated from pine weevil guts were shown to degrade a Norway spruce diterpene acid. In a metagenomic survey of the insect’s bacterial community, we were able to annotate several genes of a previously described diterpene degradation (dit) gene cluster. Antibiotic treatment disrupted the core bacterial community of H. abietis guts and eliminated nearly all dit-genes concordant with its reduction of diterpene degradation. Pine weevils reared on an artificial diet spiked with diterpenes, but without antibiotics, were found to lay more eggs with a higher hatching rate than weevils raised on diets with antibiotics or without diterpenes. These results suggest that gut symbionts contribute towards host fitness, but not by detoxification of diterpenes, since these compounds do not show toxic effects with or without antibiotics. Rather the ability to thrive in a terpene rich environment appears to allow gut microbes to benefit the weevil in other ways, such as increasing the nutritional properties of their diet.

scholarly journals Virulence and Stump Colonization Ability of Armillaria borealis on Norway Spruce Seedlings in Comparison to Sympatric Armillaria Species

Plant Disease ◽  
2017 ◽  
Vol 101 (3) ◽  
pp. 470-479 ◽  
Author(s):  
Renate Heinzelmann ◽  
Simone Prospero ◽  
Daniel Rigling
Keyword(s):  
Norway Spruce ◽  
Root Rot ◽  
Mixed Forest ◽  
Tree Age ◽  
Northern Europe ◽  
Seedling Mortality ◽  
Pathogenic Potential ◽  
Colonization Ability ◽  
Armillaria Species ◽  
Stem Segments

Although Armillaria borealis is one of the closest relatives of the aggressive root rot pathogen A. ostoyae, little is known about its ecology. In central and northern Europe, A. borealis often co-occurs with A. ostoyae or A. cepistipes, a weak pathogen, in conifer or mixed-forest stands. In this study, the virulence of 10 A. borealis, nine A. ostoyae, and five A. cepistipes isolates toward 2- and 4-year-old potted Norway spruce (Picea abies) seedlings was assessed. In addition, the ability of all isolates to colonize fresh stumps cut from 6-year-old Norway spruce seedlings was tested. All inoculations were done by insertion of Armillaria-colonized hazelnut stem segments into the soil substrate. On the 2-year-old seedlings, A. borealis and A. ostoyae showed, overall, a similar virulence 29 months after inoculation whereas, on the 4-year-old seedlings, A. ostoyae was more virulent. The third species in the experiment, A. cepistipes, caused almost no seedling mortality. Six months after cutting, the highest percentage of stumps was colonized by A. ostoyae (94.3%), followed by A. borealis (85.2%), and A. cepistipes (78.4%). Our inoculation experiments show that A. borealis has a clear pathogenic potential toward Norway spruce seedlings. However, compared with A. ostoyae, damage caused by A. borealis may decrease more rapidly with increasing tree age. Similar to other Armillaria species, A. borealis seems to be an efficient colonizer of fresh stumps.

scholarly journals Genetic variation in resistance of Norway spruce seedlings to damage by the pine weevil Hylobius abietis

2017 ◽  
Vol 13 (5) ◽  
Author(s):  
Rafael Zas ◽  
Niklas Björklund ◽  
Luis Sampedro ◽  
Claes Hellqvist ◽  
Bo Karlsson ◽  
...  
Keyword(s):  
Genetic Variation ◽  
Norway Spruce ◽  
Hylobius Abietis ◽  
Pine Weevil

Regeneration of European boreal forests: Effectiveness of measures against seedling mortality caused by the pine weevil Hylobius abietis

2011 ◽  
Vol 262 (12) ◽  
pp. 2354-2363 ◽  
Author(s):  
Göran Nordlander ◽  
Claes Hellqvist ◽  
Karin Johansson ◽  
Henrik Nordenhem
Keyword(s):  
Boreal Forests ◽  
Hylobius Abietis ◽  
Seedling Mortality ◽  
Pine Weevil

Pine weevil (Hylobius abietis) damage to cuttings and seedlings of Norway spruce

2002 ◽  
Vol 160 (1-3) ◽  
pp. 11-17 ◽  
Author(s):  
Mats Hannerz ◽  
Åke Thorsén ◽  
Staffan Mattsson ◽  
Jan Weslien
Keyword(s):  
Norway Spruce ◽  
Hylobius Abietis ◽  
Pine Weevil

DEVELOPMENT OF WHITE SPRUCE AND ALPINE FIR SEEDLINGS ON CUT-OVER AREAS IN THE CENTRAL INTERIOR OF BRITISH COLUMBIA

1965 ◽  
Vol 41 (4) ◽  
pp. 419-431 ◽  
Author(s):  
Slavoj Eis
Keyword(s):  
Root Zone ◽  
Mineral Soil ◽  
Growing Season ◽  
White Spruce ◽  
Root Penetration ◽  
Living Tissue ◽  
Seedling Mortality ◽  
Air Temperatures ◽  
Forest Sites ◽  
Wilting Point

Germination of white spruce and alpine fir was similar on mineral soil at all forest sites studied and averaged 33 per cent for spruce and 6 per cent for alpine fir.Mortality of seedlings in mineral soil was confined to the period of summer droughts. During this period maximum air temperatures approached 100° F., mineral soil exceeded 120° F. and humus 135° F. Water content of the upper 20 to 40 mm. of mineral soil was reduced below the wilting point and approximately 45 per cent of the seedlings died. The average root length of seedlings which died was 18 mm.; of those which survived, 37 mm. Greatest mortality occurred on fully exposed plots of dry habitats.On undisturbed seedbeds, germination of both species was very low. Seeds remained suspended and had insufficient contact with humic particles. Radicles of seeds which did germinate failed to reach compacted moist horizons. At the depth of root penetration, raw humus was at wilting point a few days after rain. A negligible number of seedlings of either species survived on raw humus to the end of the growing season.Shoot growth of both species ended at the beginning of August, while roots kept increasing in length until late in fall. The depth of root penetration on mineral seedbeds was greatest on sandy soils. At the end of the growing season alpine fir seedlings were larger than spruce seedlings.The main cause of seedling mortality on both types of seedbed appears to be the water deficit in the root zone. Increased mortality on fully exposed plots can be attributed to the direct heating of the living tissue under water stress.

Effects of planting time on pine weevil (Hylobius abietis) damage to Norway spruce seedlings

2016 ◽  
Vol 31 (3) ◽  
pp. 262-270 ◽  
Author(s):  
Kristina Wallertz ◽  
Kjersti Holt Hanssen ◽  
Karin Hjelm ◽  
Inger Sundheim Fløistad
Keyword(s):  
Norway Spruce ◽  
Hylobius Abietis ◽  
Planting Time ◽  
Pine Weevil
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