Natural-Control Factors Affecting the Spruce Budworm

1948 ◽  
Vol 41 (3) ◽  
pp. 457-464 ◽  
Author(s):  
Philip B. Dowden ◽  
W. D. Buchanan ◽  
V. M. Carolin
Keyword(s):  
Spruce Budworm ◽  
Natural Control ◽  
Factors Affecting ◽  
Control Factors

Natural Control Factors Affecting the Spruce Budworm in the Adirondacks During 1946–19481

1950 ◽  
Vol 43 (6) ◽  
pp. 774-783 ◽  
Author(s):  
Philip B. Dowden ◽  
V. M. Carolin ◽  
C. O. Dirks
Keyword(s):  
Spruce Budworm ◽  
Natural Control ◽  
Factors Affecting ◽  
Control Factors

scholarly journals A RECENT SPRUCE BUDWORM OUTBREAK IN THE LOWER ST. LAWRENCE AND GASPE PENINSULA WITH REFERENCE TO AERIAL SPRAYING OPERATIONS

1960 ◽  
Vol 36 (3) ◽  
pp. 209-224 ◽  
Author(s):  
J. R. Blais ◽  
R. Martineau
Keyword(s):  
Spruce Budworm ◽  
Balsam Fir ◽  
Spray Application ◽  
Natural Control ◽  
Insect Abundance ◽  
Factors Associated ◽  
Control Factors ◽  
Aerial Spraying ◽  
Eventual Collapse ◽  
Gaspe Peninsula

The main topics discussed in this paper are: the progress of the spruce budworm outbreak in the Lower St. Lawrence - Gaspé regions from 1949 to 1956; the areas sprayed between 1954 and 1958; timing of spray application in relation to insect abundance and development; effects of treatment on spruce budworm populations and on defoliation of balsam fir; results of aerial defoliation surveys and egg surveys; estimated amounts of wood destroyed by the insect, and losses averted through spraying; the various natural control factors associated with the decline and the eventual collapse of the outbreak.

Control of a Spruce Budworm Outbreak in Quebec through Aerial Spraying Operations

1963 ◽  
Vol 95 (8) ◽  
pp. 821-827 ◽  
Author(s):  
J. R. Blais
Keyword(s):  
Spruce Budworm ◽  
Combined Effects ◽  
Natural Control ◽  
Aerial Application ◽  
Infested Area ◽  
Chemical Treatments ◽  
Control Factors ◽  
Outbreak Area ◽  
Aerial Spraying

AbstractAn attempt was made to suppress an incipient spruce budworm outbreak in the Lower St. Lawrence region of Quebec through the aerial application of DDT. Operations began in 1960 and continued in 1961 and 1962 when they finally met with success. Failure to achieve success earlier was due partly to the exceptionally favourable survival conditions for the insect in 1960, and partly to the inadvertent omission of a small infested area from the program in 1961. The operations greatly reduced spruce budworm populations each year in the outbreak area, while the action of natural control factors, including parasites and predators increased. The collapse of the outbreak was the result of the combined effects of the chemical treatments and of natural control factors.

NOTES ON THE INSECT PARASITES OF THE SPRUCE BUDWORMCHORISTONEURA FUMIFERANA (CLEM.) IN BRITISH COLUMBIA

1948 ◽  
Vol 80 (1-12) ◽  
pp. 138-155 ◽  
Author(s):  
A. Wilkes ◽  
H. C. Coppel ◽  
W. G. Mathers
Keyword(s):  
British Columbia ◽  
Insect Pests ◽  
Spruce Budworm ◽  
Good Deal ◽  
Natural Control ◽  
Forest Insect ◽  
General Account ◽  
Control Factors ◽  
Insect Parasites

The spruce budworm, Choristoneura (Archips) fumiferana (Clem.) (Tortricidae) has long been considered one of the most injurious forest insect pests in Canada. A general account of past outbreaks and an outline of its biology and bahits are given by Swaine and Craighead (1924). At the time these studies were made investigations were also undertaken by J.D. Tothill and A.B. Baird on the parasites and other natural control factors of the spruce budworm, but although a good deal of work was done, brief reference to which is made by Hewitt (1911, 1912, 1913), very little has been published.

INTERACTION OF EVENING GROSBEAK (HESPERIPHONA VESPERTINA) AND SPRUCE BUDWORM (CHORISTONEURA FUMIFERANA (CLEM.)) IN A LOCALIZED BUDWORM OUTBREAK TREATED WITH DDT IN QUEBEC

1964 ◽  
Vol 42 (6) ◽  
pp. 1017-1024 ◽  
Author(s):  
J. R. Blais ◽  
G. H. Parks
Keyword(s):  
Chemical Treatment ◽  
Critical Period ◽  
Direct Evidence ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Combined Effects ◽  
Natural Control ◽  
Control Factors ◽  
Outbreak Area ◽  
Large Numbers

Control of a localized spruce budworm outbreak in southeastern Quebec was achieved through the combined effects of chemical treatment with DDT and natural control factors. Amongst the latter, predation by evening grosbeaks was suspected to have been of considerable importance. It appears that the birds were attracted to the outbreak area in unusually large numbers during their spring migration. The yearly influx of the grosbeaks in the area occurred when the budworm was in the late larval and the pupal stages, an especially critical period with respect to generation survival of this insect. In 1963, the year following collapse of the outbreak, very few grosbeaks were seen in the area. There was no direct evidence that the birds suffered ill effects from the spraying operation.

Improving the Strength of Abrasive Wheels and Optimizing the Control over the Strength of Composite Abrasive Materials

2019 ◽  
Vol 946 ◽  
pp. 380-385
Author(s):  
Boris A. Chaplygin ◽  
Viacheslav V. Shirokov ◽  
Tat'yana A. Lisovskaya ◽  
Roman A. Lisovskiy
Keyword(s):  
Mechanical Properties ◽  
Test Results ◽  
Key Factors ◽  
Special Equipment ◽  
Material Density ◽  
Factors Affecting ◽  
Control Factors ◽  
Reinforcing Material ◽  
Special Studies ◽  
First Time

The strength of abrasive wheels is one of the key factors affecting the performance of abrasive machining. The paper discusses ways to improve the strength of abrasive wheels. The stress-state mathematical model presented herein is a generalization of the existing models. It is used herein to find for the first time that there are numerous optimal combinations of the elastic modulus and reinforcing material density, which result in the same minimum value of the objective function. It is found out that increasing the radius of the reinforcing component while also optimizing the mechanical properties of its material may increase the permissible breaking speed of the wheel several times. We herein present a regression equation and a nomogram for finding the optimal combination of control factors. Conventional methods for testing the mechanical properties of materials, which have been proven reliable for testing metals and alloys, are not as reliable for testing abrasive materials, as the test results they generate are not sufficiently stable or accurate. We therefore propose an alternative method that does not require any special equipment or special studies.

FACTORS AFFECTING ADULT EMERGENCE AND MATING BEHAVIOR OF THE EASTERN SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1975 ◽  
Vol 107 (9) ◽  
pp. 967-977 ◽  
Author(s):  
C. J. Sanders
Keyword(s):  
Field Experiments ◽  
Choristoneura Fumiferana ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Field Conditions ◽  
Continuous Illumination ◽  
Degree Days ◽  
Factors Affecting ◽  
Eastern Spruce Budworm ◽  
Duration Of Copulation

AbstractLaboratory and field experiments indicate that the female spruce budworm (Choristoneura fumiferana (Clem.)) pupal stadium requires approximately 122C degree-days above a threshold of 7.2 °C (45°F), the male 124. Emergence time on any given day depends on temperature but is independent of photoperiod. Under field conditions male and female budworm mate only once per 24-h period. In the laboratory under continuous illumination females mate repeatedly and males readily mate a second time within a few hours, but the duration of the second copulation is abnormally long. The probability of multiple matings under field conditions is reduced by the restricted period of sexual activity coupled with the duration of copulation and the lower competitiveness of mated insects. Antennae are essential to the male for successful copulation.

Design analysis of a standard injection screw for plasticising polycarbonate resins

2016 ◽  
Vol 36 (5) ◽  
pp. 537-548 ◽  
Author(s):  
Ming-Shyan Huang
Keyword(s):  
Simulation Analysis ◽  
Melt Temperature ◽  
Factors Affecting ◽  
Control Factors ◽  
Screw Length ◽  
Plastic Injection Moulding ◽  
Screw Diameter ◽  
Grey Relational ◽  
Injection Screw ◽  
Simulation Programme

Abstract The industrial use of plastic injection moulding machines is widespread. However, few studies have examined the injection screw, which is one of the key components of moulding machines. Studies have demonstrated that a properly designed injection screw improves both the moulding quality and the production rate. Factors that affect the plasticisation properties of conventional standard reciprocating screws include the screw geometry, the screw operation settings, and the processed resins. An ideal standard reciprocating screw exhibits a high plasticising capacity and excellent melt temperature homogeneity; however, these properties typically conflict. Through simulation analysis, this study investigated the optimal design of a standard reciprocating injection screw used for plasticising polycarbonate resins. First, the Taguchi method was integrated with a commercial simulation programme to identify the key control factors affecting the plasticising rate of a screw and the temperature uniformity of the melt. Simulation results revealed that the screw diameter, rotation speed, metering channel depth, ratio of the screw length to the screw diameter, and compression ratio substantially influence performance. Consequently, grey relational analysis was adopted to optimise the design of an injection screw that ensures sufficient quality according to the plasticisation rate and the homogeneity of molten plastic.

Preparation and Application of Biochars for Organic and Microbial Control in Wastewater Treatment Regimes

2019 ◽  
pp. 19-34 ◽  
Author(s):  
Victor Odhiambo Shikuku ◽  
Wilfrida N. Nyairo ◽  
Chrispin O. Kowenje
Keyword(s):  
Organic Pollutants ◽  
Organic Contaminants ◽  
Activated Carbons ◽  
Low Cost ◽  
Microbial Control ◽  
Chemical Compositions ◽  
Preparation Methods ◽  
Factors Affecting ◽  
Surface Areas ◽  
Control Factors

Biochars have been extensively applied in soil remediation, carbon sequestration, and in climate change mitigation. However, in recent years, there has been a significant increase in biochar research in water treatment due to their stupendous adsorptive properties for various contaminants. This is attributed to their large surface areas, pore structures, chemical compositions, and low capital costs involved making them suitable candidates for replacing activated carbons. This chapter discusses the preparation methods and properties of biochars and their removal efficacy for organic contaminants and microbial control. Factors affecting adsorption and the mechanisms of adsorption of organic pollutants on biochars are also concisely discussed. Biochars present environmentally benign and low-cost adsorbents for removal of both organic pollutants and microbial control for wastewater purification systems.

Simulation of Skulduggery in a Multi-Agent System

2015 ◽  
Vol 7 (1) ◽  
pp. 17-31
Author(s):  
Rasoul Ramezanian ◽  
Akram Emdadi
Keyword(s):  
Utility Function ◽  
Test Session ◽  
Testing Session ◽  
Multi Agent System ◽  
Agent System ◽  
Factors Affecting ◽  
Artificial Society ◽  
Control Factors ◽  
Multi Agent ◽  
Level Of Knowledge

In a testing session, students may want to use the information of other students, which is cheating. The authors of this paper develop an artificial society to model and simulate this situation. They consider two control factors to increase the incentive of students to not cheat. The first factor is the penalty for similarity between responses (as much as two answer-sheets of two students are the same, their final grades decrease). The second factor is the observers who look into the students and do not allow the observed students to cheat. In this model, agents participate in a test based on their level of knowledge, location and two above factors, deciding whether or not to cheat. These components are used to formulate the utility function. Taking advantage of the developed artificial society, the authors now study the above factors affecting the amount of cheating in a test session.

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