Snytbaggen

Barrträdsplantor som planterats efter avverkning blir ofta dödade av snytbaggens gnag. Men genom olika åtgärder kan skadorna minskas till en acceptabel nivå. Vilka metoder du bör välja beror bland annat på var i landet hygget ligger. Denna broschyr syftar till att förklara vilken effekt på plantskadorna olika åtgärder ger och hur de kan kombineras i olika delar av Sverige

Trap catch data are poor predictors of damage caused by pine weevil (Hylobius abietis) to conifer seedlings

Damage to planted conifer seedlings caused by the pine weevil Hylobius abietis (L.) is a severe and persistent threat to successful forest regeneration in Europe. Various countermeasures are available, which vary in effectiveness, costs and environmental impact, but none are ideal for all situations. Therefore, there is strong interest in robust assessments of damage risks, as they would enable more cost-effective and environmentally friendly forest pest management. It has been suggested that numbers of adult pine weevils caught in host-odour baited traps placed in regeneration sites may be valuable in such risk assessments. However, published studies provide at most weak support for the hypothesis that trap catch data provide adequate predictions of damage. Therefore, we conducted a two-year field study, designed to determine the relationship between weevil trap catch and subsequent damage at 10 regeneration sites in central Sweden. Site factors that might influence pine weevil feeding on seedlings were recorded and used as explanatory variables in the analysis. Stoniness was the only site factor identified as having a significant effect; damage mainly increased with increases in stoniness. No significant correlation was detected between damage to planted conifer seedlings and numbers of pine weevils trapped in the same locations. We suggest that this lack of correlation between weevil numbers and damage is due to planted seedlings only constituting a minor part of the weevils food intake and considerable between-site variation in availability of food sources other than seedlings. Therefore, assessment of pine weevil numbers appears unlikely to be useful for predicting damage risk at specific regeneration sites

Influence of climate and forest management on damage risk by the pine weevil Hylobius abietis in northern Sweden

The pine weevil 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.Hylobius abieti

Etablering, tillväxt och skador för plantor odlade i såddrör (Tubesprout™) - resultat efter två säsonger i fält

Försöket visade på mycket god överlevnad för plantor odlade i såddrören, Tubesprout™. Efter två år var överlevnaden för dessa 91 % för tall och 79 % för gran. För miniplantorna odlade i Jiffy varierade överlevnaden efter två år mellan 84 (tall) och 64 % (gran). Lägst överlevnad efter både det första och andra året hade de större referensplantorna. Av dessa levde 67 % av tallplantorna och endast 45 % av granplantorna. Bidragande till den goda överlevelsen hos Tubesprout™-odlade plantor var få snytbaggeskador och nästan inga skador av torka. Det andra miniplantsystemet, Jiffy 18, klarade snytbaggen nästan lika bra som Tubesprout™, men drabbades istället av stora avgångar beroende på torka. Hylsan tycks förhindra uttorkning av plantan som annars är ett stort problem vid plantering på torra marker av små plantor. För de äldre täckrotsodlade referensplantorna var den mesta plantdöden orsakad av kraftiga snytbaggeskador. Granen var värst drabbad med drygt 50 % snytbaggedödade plantor efter två år, medan den plantavgång hos tall som var orsakad av snytbagge var 26 %. Några plantor som stod i Tubesprout™ på försöksytan blev dock uppryckta, sannolikt av kråkfåglar

Pubertal timing predicts previous fractures and BMD in young adult men: the GOOD study.

The importance of pubertal timing for adult BMD in males was studied through association of pubertal timing with young adult bone phenotype. Pubertal timing was found to predict both cortical and trabecular volumetric BMD and previous fractures in young adult men. Thus, late puberty is a risk factor for low BMD and previous fractures in young adult men. INTRODUCTION: Peak bone mass (PBM), achieved during puberty, is a determinant of the risk for osteoporosis and future fractures. The role of variations within the normal range in pubertal timing for fractures during pubertal development and for adult bone mass in men is unknown. MATERIALS AND METHODS: The aim of this study was to investigate the importance of pubertal timing for adult BMD and for fractures before achievement of PBM in men. The population-based Gothenburg Osteoporosis and Obesity Determinants (GOOD) study is a well-characterized cohort of young adult Swedish males 18-20 years of age. Detailed growth charts from birth to 18-20 years of age were retrieved for 642 men participating in the GOOD study. Age at peak height velocity (PHV) was estimated and used as an assessment of pubertal timing. The skeletal phenotype was analyzed at young adult age using DXA and pQCT and previous fractures were assessed by questionnaires. RESULTS: Age at PHV was a negative independent predictor of both adult cortical and trabecular volumetric BMD and of total body and radius areal BMD. Moreover, age at PHV was associated with previous fractures in a logistic regression analysis. The OR for cortical osteopenia was 2.49 (95% CI, 1.91-3.24;

Interleukin-1 system gene polymorphisms are associated with fat mass in young men.

CONTEXT: There is growing evidence for interactions between the regulation of body fat and the immune system. Studies of knockout mice indicate that IL-1 has an antiobesity effect. OBJECTIVE: The objective of the study was to investigate our hypothesis that common polymorphisms of the IL-1 system, which are associated with IL-1 activity, also are associated with fat mass. DESIGN, SETTING, AND STUDY SUBJECTS: The Gothenburg Osteoporosis and Obesity Determinants (GOOD) study is a population-based cross-sectional study of 18- to 20-yr-old men (n = 1068), mostly Caucasian, from the Gothenburg area (Sweden). Three different polymorphisms, IL-1beta +3953 C/T, IL-1beta-31 T/C, and IL-1 receptor antagonist (IL-1RN) variable number tandem repeat of 86 bp, were investigated in relation to body fat mass. MAIN OUTCOME MEASURE: The main outcome measures were genotype distributions and their association with body fat mass in different compartments, measured with dual-energy x-ray absorptiometry. RESULTS: Carriers of the T variant (CT and TT) of the +3953 C to T (F(T) = 0.25) IL-1beta gene polymorphism had significantly lower total fat mass (P = 0.013) and also significantly reduced arm, leg, and trunk fat, compared with CC individuals. IL-1RN*2 carriers with two repeats of the IL-1RN variable number tandem repeat polymorphism had increased total fat (P = 0.036), serum leptin, and fat of trunk and arm as well as serum levels of IL-1RN and IL-1RN production ex vivo. The IL-1beta-31 polymorphism did not correlate with the fat measurements. CONCLUSIONS: The IL-1 system, recently shown to affect fat mass in experimental animals, contains gene polymorphisms that are associated with fat mass in young men

Quantitative Structure-Activity Relationships of Pine Weevil Antifeedants, a Multivariate Approach

Antifeedant activity of mainly phenylpropanoic, cinnamic, and benzoic acids esters was tested on the pine weevil, Hylobius abietis (L.). Of 105 compounds screened for activity, 9 phenylpropanoates, 3 cinnamates, and 4 benzoates were found to be highly active antifeedants. To understand the structure-activity relationships of these compounds, a multivariate analysis study was performed. A number of molecular and substituent descriptors were calculated and correlated to results from two-choice feeding tests with H. abietis. Three local models were developed that had good internal predictive ability. External test sets showed moderate predictivity. In general, low polarity, small size, and high lipophilicity were characteristics for compounds having good antifeedant activity