A Comparison of the Developmental Rates of One- and Two-Year Cycle Spruce Budworm

1961 ◽  
Vol 93 (9) ◽  
pp. 764-771 ◽  
Author(s):  
R. F. Shepherd
Keyword(s):  
Boreal Forests ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Western United States ◽  
First Year ◽  
Mountainous Areas ◽  
Developmental Rates ◽  
Second Year ◽  
One Year ◽  
The One

The spruce budworm, Choristoneura fumiferana (Clem.), is indigenous to most of the boreal forests in Canada and adjacent Eastern and Western United States. Throughout most of this range the budworm maintains a one-year cycle, overwintering as second instar larvae. In some mountainous areas of Alberta and British Columbia, a form of the budworm has a two-year cycle and over-winters as second instar larvae in the first year and as fourth instar larvae in the second year. The habitat temperatures of these two forms were investigated and related to rates of development in an attempt to discover the environmental factor which maintains the two-year cycle budworm as a distinct form even though it is geographically surrounded by the one-year cycle budworm.

One and two years impact of commercial thinning on spruce budworm feeding ecology and host tree foliage production and chemistry

1996 ◽  
Vol 72 (4) ◽  
pp. 393-398 ◽  
Author(s):  
Éric Bauce
Keyword(s):  
Choristoneura Fumiferana ◽  
Soluble Sugars ◽  
Abies Balsamea ◽  
Basal Area ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
First Year ◽  
Commercial Thinning ◽  
Mill Stand ◽  
Second Year

Field rearing experiments of spruce budworm, Choristoneura fumiferana (Clem.), were conducted in conjunction with foliar chemical analyses, one and two years after a commercial thinning (removal of 25% stand basal area) in a 50-year-old balsam fir, Abies balsamea (L.) Mill., stand. The first year after thinning, spruce budworm larvae reared on the residual trees developed five days faster and removed 43% more foliage than those reared on control trees, but in the second year they developed two days faster and removed 37% more foliage. The increase in larval development rate was related to an increase in foliar soluble sugars while a reduction in foliar monoterpenes caused by the thinning apparently accounted for the greater amount of foliage ingested by the larvae. The first year after thinning, trees were more vulnerable to spruce budworm because there was no increase in foliage production and the trees were more heavily defoliated. However, in the second year trees were less vulnerable to the insect because there was an increase in foliage production that exceeded the increase in defoliation, hence a net gain in foliage. Results from this study showed that commercial thinning could reduce the vulnerability of balsam fir trees to spruce budworm if thinning is conducted two years prior to budworm outbreak, but the same silvicultural procedure could increase the vulnerability to the insect if it is conducted during an outbreak. Key words: spruce budworm, balsam fir, chemistry, thinning, defoliation

scholarly journals NOTES ON A SPRUCE BUDWORM INFESTATION IN BRITISH COLUMBIA

1960 ◽  
Vol 36 (4) ◽  
pp. 362-374 ◽  
Author(s):  
G. T. Silver
Keyword(s):  
British Columbia ◽  
Pseudotsuga Menziesii ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Douglas Fir ◽  
Population Trends ◽  
Seasonal Development ◽  
Host Trees ◽  
One Year ◽  
The One

An outbreak of the one-year cycle spruce budworm, Choristoneura fumiferana (Clem.), on Douglas fir, Pseudotsuga menziesii (Mirb.) Franco, which lasted six years before collapsing, is described. Population trends and seasonal development, effect of defoliation on the host trees and parasites of the insect are discussed.

Timing of growth reductions in black spruce stem and branches during the 1970s spruce budworm outbreak1This article is one of a selection of papers from the 7th International Conference on Disturbance Dynamics in Boreal Forests.

2012 ◽  
Vol 42 (7) ◽  
pp. 1220-1227 ◽  
Author(s):  
Cornelia Krause ◽  
Boris Luszczynski ◽  
Hubert Morin ◽  
Sergio Rossi ◽  
Pierre-Y. Plourde
Keyword(s):  
Picea Mariana ◽  
Boreal Forests ◽  
Radial Growth ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
First Year ◽  
Growth Reduction ◽  
Lower Stem ◽  
Selection Of

Spruce budworm ( Choristoneura fumiferana (Clemens)) defoliation is known to regularly produce radial growth decrease in black spruce ( Picea mariana (Mill.) Britton, Sterns & Poggenb.) in the boreal forest of Quebec. Some studies have already shown that the first year of defoliation does not induce growth losses in the stem but could occur in other tree parts. We therefore examined the timing and duration of the growth reduction caused by the last outbreak in black spruce by also considering the branches. More than 79% of branches and 65% of stems exhibited a >40% growth decrease.The reduction was first registered in the upper part of the stem before being detected lower in the stem in 87% of the trees. Probabilities of growth reduction in the upper part of the stem were highest in 1976 and 1977. In the lower stem, the probabilities were highest in 1978. An interesting finding was that in 69% of the studied stands, the probability of growth reduction started earlier (1–2 years) in the branches than in the stem at 1.3 m. Branch analysis should be considered whenever questions arise in regard to the evolution of spruce budworm defoliation as well as the timing of observed growth reduction in black spruce.

Derivation of Pheromone-Based Larval Thresholds in Spruce Budworm Accounting for Distance to Defoliated Forest Stands

2021 ◽  
Author(s):  
Marc Rhainds ◽  
Ian DeMerchant ◽  
Pierre Therrien
Keyword(s):  
Boreal Forests ◽  
Large Scale ◽  
Choristoneura Fumiferana ◽  
Intervention Strategy ◽  
Spruce Budworm ◽  
Interactive Effects ◽  
The Novel ◽  
Forest Stands ◽  
General Guideline ◽  
Number Of Males

Abstract Spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is the most severe defoliator of Pinaceae in Nearctic boreal forests. Three tools widely used to guide large-scale management decisions (year-to-year defoliation maps; density of overwintering second instars [L2]; number of males at pheromone traps) were integrated to derive pheromone-based thresholds corresponding to specific intergenerational transitions in larval densities (L2i → L2i+1), taking into account the novel finding that threshold estimates decline with distance to defoliated forest stands (DIST). Estimates of thresholds were highly variable between years, both numerically and in terms of interactive effects of L2i and DIST, which limit their heuristic value. In the context of early intervention strategy (L2i+1 > 6.5 individuals per branch), however, thresholds fluctuated within relatively narrow intervals across wide ranges of L2i and DIST, and values of 40–200 males per trap may thus be used as general guideline.

scholarly journals Fertilizing of young rubber in the Cameroons.

1960 ◽  
Vol 8 (3) ◽  
pp. 165-178
Author(s):  
H.N. Hasselo
Keyword(s):  
Phosphate Rock ◽  
Growth Response ◽  
Nutrient Status ◽  
Nutrient Supply ◽  
Parent Material ◽  
Rooting Depth ◽  
First Year ◽  
Second Year ◽  
One Year ◽  
Shallow Soils

The growth response to (NH4)2SO4, phosphate rock and KC1, given in all combinations at increasing annual rates of up to 24 oz/tree until the seventh year after planting, was measured by the girth increase of Hevea in three soils formed from the same parent material but possessing different nutrient status and depths to the root-impeding layers. Despite poor nutrient supply in the soil, lack of rooting depth had a greater effect on growth than had nutrient availability; while abundant nutrient supply reduced the unproductive period by half a year, this reduction was at least one year in shallow soils. Annual fluctuations in yield were reduced by balanced application of small amounts of fertilizers. Fertilized trees, opened up at 18-inch girth, yielded 430 lb/acre in the first year whether given balanced fertilizer or not; in the second year, trees given balanced fertilizer yielded 700 lb as compared with 580 lb without fertilizer. (Abstract retrieved from CAB Abstracts by CABI’s permission)

Second Diapause in Spruce Budworm from Eastern Canada

1961 ◽  
Vol 93 (7) ◽  
pp. 594-602 ◽  
Author(s):  
George T. Harvey
Keyword(s):  
British Columbia ◽  
Experimental Analysis ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Fourth Instar ◽  
Eastern Canada ◽  
Low Incidence ◽  
One Year ◽  
Storage Times ◽  
Second Period

In eastern Canada larvae of the spruce budworm, Choristoneura fumiferana (Clem.), complete their development in one year, undergoing only one period of winter diapause in the second instar, whereas in certain parts of British Columbia, at high altitudes, two years are normally required for development, the larvae spending a second period of winter diapause in the fourth instar (3, 9). Among laboratory-reared eastern budworm there are a few individuals that enter a similar second diapause (7). The low incidence and somewhat irregular occurrence of this second diapause in eastern budworm, even in laboratory rearings, have hitherto made detailed studies almost impossible, but unusual storage times and treatments used recently in rearing experiments had the unexpected effect of increasing the incidence of this tvpe of behaviour to a level where experimental analysis became possible. This paper describes these larvae and their behaviour; an account of the effects of various conditions upon the incidence of second diapause will be presented later.

scholarly journals Incidence of surgical procedures for gastrointestinal complications after abdominal wall closure in patients with gastroschisis and omphalocele

2021 ◽  
Author(s):  
M. Haghshenas ◽  
U. Rolle ◽  
M. Hutter ◽  
T. M. Theilen
Keyword(s):  
Abdominal Wall ◽  
Surgical Procedures ◽  
Retrospective Chart Review ◽  
First Year ◽  
Special Focus ◽  
Abdominal Wall Closure ◽  
Gastrointestinal Complications ◽  
Secondary Operations ◽  
One Year ◽  
The One

Abstract Purpose This study aims to define the extent of additional surgical procedures after abdominal wall closure (AWC) in patients with gastroschisis (GS) and omphalocele (OC) with special focus on gastrointestinal related operations. Methods A retrospective chart review was performed including all operations in GS and OC patients in the first year after AWC (2010–2019). The risk for surgery was calculated using the one-year cumulative incidence (CI). Results 33 GS patients (18 simple GS, 15 complex) and 24 OC patients (12 without (= OCL), 12 OC patients with liver protrusion (= OCL +)) were eligible for analysis. 43 secondary operations (23 in GS, 20 in OC patients) occurred after a median time of 84 days (16–824) in GS and 114.5 days (12–4368) in OC. Patients with complex versus simple GS had a significantly higher risk of undergoing a secondary operation (one-year CI 64.3% vs. 24.4%; p = 0.05). 86.5% of surgical procedures in complex GS and 36.3% in OCL + were related to gastrointestinal complications. Complex GS had a significantly higher risk for GI-related surgery than simple GS. Bowel obstruction was a risk factor for surgery in complex GS (one-year CI 35.7%). Conclusion Complex GS and OCL + patients had the highest risk of undergoing secondary operations, especially those with gastrointestinal complications.

scholarly journals Growth Recovery and Phenological Responses of Juvenile Beech (Fagus sylvatica L.) Exposed to Spring Warming and Late Spring Frost

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1604
Author(s):  
Kristine Vander Mijnsbrugge ◽  
Jessa May Malanguis ◽  
Stefaan Moreels ◽  
Amy Lauwers ◽  
Arno Thomaes ◽  
...  
Keyword(s):  
High Temperature ◽  
Fagus Sylvatica ◽  
Frost Damage ◽  
Late Spring ◽  
First Year ◽  
Spring Frost ◽  
Late Spring Frost ◽  
Fagus Sylvatica L ◽  
Second Year ◽  
One Year

Global change increases the risk of extreme climatic events. The impact of extreme temperature may depend on the tree species and also on the provenance. Ten provenances of Fagus sylvatica L. were grown in a common garden environment in Belgium and subjected to different temperature treatments. Half of the one year old seedlings were submitted to a high thermal stress in the spring of the first year, and all plants were exposed to a late spring frost in the second year. The high-temperature treated plants displayed reduced growth in the first year, which was fully compensated (recovery with exact compensation) in the second year for radial growth and in the third year for height growth. Frost in the spring of the second year damaged part of the saplings and reduced their growth. The frost damaged plants regained the pre-stress growth rate one year later (recovery without compensation). The high temperature treatment in the first year and the frost damage in the second year clearly influenced the phenological responses in the year of the event and in the succeeding year. Little population differentiation was observed among the provenances for growth and for phenological responses. Yet, a southern provenance, a non-autochthonous provenance (original German provenance that was planted in Belgium about a century ago) and a more continental provenance flushed earlier than the local Atlantic provenances in the year of the frost event, resulting in more frost damage. Some caution should therefore be taken when translocating provenances as an anticipation of the predicted climate warming.

scholarly journals Fungi colonizing various organs of thyme Thymus vulgaris L. cultivated in the region of Lublin

2013 ◽  
Vol 55 (1) ◽  
pp. 185-197
Author(s):  
Zofia Machowicz-Stefaniak ◽  
Beata Zimowska ◽  
Ewa Zalewska
Keyword(s):  
Culture Medium ◽  
Pathogenic Fungi ◽  
Malt Agar ◽  
Thymus Vulgaris ◽  
Thielaviopsis Basicola ◽  
Fusarium Spp ◽  
Disease Symptoms ◽  
Second Year ◽  
One Year ◽  
The One

In 1998-2001, the healthiness of thyme cultivated in the region of Lublin was examined. Surveys were made on the one-year-old plantations of thyme at a stage of 6-week-old seedlings and just before the first harvest of the crop, as well as on the two-year-old plantations in spring and before the last harvest. The percentage of the plants showing fungal disease symptoms and the index of infection with fungi were determined. The fungi were isolated from superficially disinfected plant fragments namely from roots, bases of stem and leaves, separately, using mineral culture medium. PDA and SNA media were used to culture <i>Fusarium</i> spp., malt-agar and Czapek-Dox ones to culture <i>Penicillium</i> spp. and malt-agar, oat-agar and cherry-agar ones to culture <i>Phoma</i> spp. The percentage of plant infected with the fungi ranged within 12.18 and 23.05, in case of the one-year-old plantations, and within 29.91 and 43.65 in the two-year-old ones, whereas values of the index of infection ranged within 11.56 and 24.69 and within 20.75 and 43,28, respectively. Necroses were observed on roots and base of stems on one-year-old and two-year-old plantations, but in the last period of vegetation of thyme close to harvest. very often stems and leaves showed symptoms of a complete necrosis. It was found that base of stems and roots of thyme in the first and the second year of cultivation were colonized by a complex of pathogenic fungi:<i>Fusarium spp., Rhizoctonia solani, Thielaviopsis basicola</i> were obtained from the major part of diseased plants. Among the <i>Fusarium</i> species colonizing bases of stems <i>F.culmorum, F.avenaceum, F.equiseti</i> and <i>F.oxysporum</i> dominated, but from roots of thyme most often <i>F.oxysporum, F.equiseti and F.culmorum</i> were isolated. From stems, and particularly from leaves of thyme showing dark spots, commonly <i>Alternaria alternata</i> was obtained. On the other hand, shoots and leaves, but rarely roots of thyme, were colonized by various species of <i>Phoma</i>, particularly by <i>Phoma exigua</i> var. <i>exigua. Colletotrichum gleosporioides</i> occurred rarely on thyme in the area surveyed.

scholarly journals Risk factors associated with the development of death events during the first year of follow-up after pulmonary thromboembolism

2019 ◽  
pp. 80-85
Author(s):  
S. A. Berns ◽  
E. A. Schmidt ◽  
A. G. Neeshpapa ◽  
A. A. Potapenko ◽  
K. V. Smirnov ◽  
...  
Keyword(s):  
Pulmonary Embolism ◽  
High Risk ◽  
Anticoagulant Therapy ◽  
Severe Heart Failure ◽  
First Year ◽  
Factors Associated ◽  
Risk Of Death ◽  
One Year ◽  
The One

Purpose: to identify the factors associated with the development of death events during the year follow-up after hospitalization for pulmonary embolism (PE). Materials and methods: 93 patients with PE discharged to the outpatient stage of observation were studied. 45 (61,6%) patients were female with an average age of 66 years. The examination of patients at the stage of inclusion in the study consisted of standard methods of examination for this pathology. The diagnosis was confirmed by multislice computed tomography. Follow-up was 12 months. Statistical analysis was performed using the MedCalc Version 16.2.1. Results: during the one-year follow-up period 62 (66,7%) patients with PE were alive but 11 patients (11,8%) died, and no information was obtained about 20 patients. The causes of death were as follows: the development of recurrent PE – 4 (36,4%) patients, cancer – 3 patients (27,3%), stroke – 2 (18,1%), one patient (9,1%) died due to severe heart failure and one – myocardial infarction. A comparative analysis in the groups of alive patients (n = 62) and patients with a fatal events (n = 11) showed that the dead patients were older (78 (68; 81) vs. 65 (49; 75) years; p = 0,003), had a higher PESI score (119,0 (99,7; 137,2) vs. 88,0 (68,0; 108,0); p = 0,016) and were less compliant to prolonged anticoagulant therapy during the one year of observation (45,5% of patients (n = 5) vs. 82,3% ( = 51); p = 0,015). The ROC curve determined that a high risk of death during the one year after PE is associated with age over 70 years (p = 0,0001) and more than 95 points by PESI in the hospital period (p = 0,0001). Conclusion: The death events were developed in 11,8% of cases in patients with pulmonary embolism during the first year of follow-up. The death outcomes were significantly associated with elderly age, intermediate and high risk by PESI in the hospital period and low compliance to anticoagulant therapy extended during the year after pulmonary embolism.

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