THE DEVELOPMENT OF LIFE TABLES FOR THE SPRUCE BUDWORM

1954 ◽  
Vol 32 (4) ◽  
pp. 283-301 ◽  
Author(s):  
R. F. Morris ◽  
C. A. Miller
Keyword(s):  
Human Life ◽  
Spruce Budworm ◽  
Life Tables ◽  
Control Measures ◽  
Permanent Plots ◽  
Mortality Factors ◽  
Green River ◽  
Population Sampling ◽  
Control Factors ◽  
Fundamental Information

A method for preparing life tables is described and two examples are presented, based on field data from the Green River Watershed in northwestern New Brunswick. Column headings for age interval (x), survivorship (lx), deaths (dx), and death rate (qx) are adopted from human life tables. An additional column, dx factor, should be added to insect life tables so that the different mortality factors can be tabulated. Life tables for the spruce budworm are based on intensive population sampling on permanent plots, complemented by data on fecundity, natural and applied control factors, and dispersion. Techniques for these basic studies will be detailed in subsequent papers. Life tables for consecutive generations of the budworm in different forest types should provide fundamental information on the epidemiology of the species and on the possible reduction of damage through forest management and through direct control measures.

The Interaction of the Spruce Budworm, Choristoneura fumiferana (Clem.), and the Parasite Apanteles fumiferanae Vier.

1959 ◽  
Vol 91 (8) ◽  
pp. 457-477 ◽  
Author(s):  
C. A. Miller
Keyword(s):  
New Brunswick ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Forest Pest ◽  
Mortality Factors ◽  
Term Study ◽  
Green River ◽  
Long Term Study ◽  
The Subject

In the late 1940's significant increases in the population of the spruce budworm, worm, Choristoneura fumiferana (Clem.), occurred in northern New Brunswick and culminated in a severe outbreak of this major forest pest. The outbreak has been the subject of intensive investigations dealing with emergency chemical control operations (Webb, 1956) and with a long-term study of the population dynamics of the budworm. The latter program, called the Green River Project, is located on the Green River Watershed in northwestern New Brunswick. Its objectives, the co-operating agencies involved, the mortality factors being studied, and methodology have been discussed elsewhere by Morris et al. (1956), Morris (1951), Morris and Miller (1954), and Morris (1955).

FACTORS AFFECTING THE MORTALITY OF LEAFMINERS ARGYRESTHIA THUIELLA AND PULICALVARIA THUJAELLA (LEPIDOPTERA: YPONOMEUTIDAE AND GELECHIIDAE) ON EASTERN WHITE CEDAR, IN ONTARIO

1979 ◽  
Vol 111 (11) ◽  
pp. 1299-1306 ◽  
Author(s):  
N. L. Bazinet ◽  
M. K. Sears
Keyword(s):  
Host Species ◽  
Life Tables ◽  
Mortality Factors ◽  
Factors Affecting ◽  
White Cedar ◽  
Eastern White Cedar ◽  
Overwintering Mortality

AbstractMortality factors affecting populations of the leafminers Argyresthia thuiella (Pack.) and Pulicalvaria thujaella (Kft.), on eastern white cedar in the area of Guelph, Ontario were identified and summarized in life tables. During the two annual generations studied from 1975 to 1977, overwintering mortality varied widely. Winterkill increased from 6.8% to 62.9% for A. thuiella and from 8.1% to 54.6% for P. thujaella, from 1976 to 1977. Several parasitoids produced substantial mortality of each host species, but their effect may have been superseded by winterkill in 1977. Data indicate that both populations of leafminers increased from 1975 to 1976 but decreased substantially from 1976 to 1977.

scholarly journals Changes in Air Pollution Following the COVID-19 Epidemic in Northern China: The Role of Meteorology

2021 ◽  
Vol 9 ◽  
Author(s):  
Tian Xian ◽  
Zhanqing Li ◽  
Jing Wei
Keyword(s):  
Air Pollution ◽  
Large Scale ◽  
Human Life ◽  
Northern China ◽  
Control Measures ◽  
Economic Activities ◽  
Low Wind Speed ◽  
Seasonal Signals ◽  
Haze Formation ◽  
Holiday Effects

COVID-19 has a tremendous impact on both human life and the environment due to the unprecedented large-scale shutdown of economic activities at the beginning of 2020. While it was widely expected to see a dramatic reduction in air pollution, reality appears to be much more complex due to the joint influences of emissions and meteorology in dictating air pollution. By analyzing ample meteorological and environmental observational data, this study attempts to evaluate the contribution of an economic lockdown or at a well-below normal level across China to air pollution during the COVID-19 pandemic in the Beijing-Tianjin-Hebei region. Besides the unprecedented emission reductions that helped to improve air quality, multiple other factors came into play, such as high humidity and low wind speed that are favorable for haze formation. After separating long-term trends, seasonal signals, holiday effects, and meteorological contributions concerning climatology, we estimated that the relative contributions of human activities to changes in particulate matter with a diameter of less than 2.5 μm and nitrogen dioxide during the epidemic were −17.13 μg/m3 and −0.03 μg/m3, respectively, with negative quantities denoting reductions to air pollution. Furthermore, comparing the changes in PM2.5 and NO2 concentrations after lockdown revealed that for short-term control measures, meteorological factors mainly affected pollutant particles.

The Biology and Control of the Sugar-cane Chafer Beetles in Tanganyika

1956 ◽  
Vol 47 (2) ◽  
pp. 377-397 ◽  
Author(s):  
W. F. Jepson
Keyword(s):  
Biological Control ◽  
Sugar Cane ◽  
Chemical Control ◽  
Parasite Species ◽  
Cultural Control ◽  
Control Measures ◽  
Mortality Factors ◽  
Resistant Varieties ◽  
And Control ◽  
Clemora Smithi

The principal pest of sugar-cane in northern Tanganyika is the Red Cane Beetle, Cochliotis melolonthoides (Gerst.) (Melolonthidae). Descriptions of adults and larvae of Cochliotis and of allied beetles found in the same area are given.The bionomics of Cochliotis have been studied in the field over two seasons. The life-cycle is annual with adult swarming in early October and a season of maximum larval damage in July–August.The intensity of infestation and the nature of the losses are discussed, and the mortality factors which act upon Cochliotis in nature are reviewed.Cultural control measures suggested include the deferment of planting until July to October, when larval activity has waned; introduction of quick-maturing varieties, mechanically cultivated so that long ratooning can be gradually eliminated; regulation of the water table by control of irrigation, and the trial of resistant varieties. The Mauritius varieties M. 134/32 and M. 165/38 are suggested in this connection.Biological control is discussed and a review of the parasite species that might possibly be introduced is made largely from the writer's Mauritius work on Clemora smithi (Arr.).Experiments in the chemical control of Cochliotis are described and the final recommendation is the application at planting of ½ lb. per 50 ft. of furrow of a BHC powder containing 2·5 per cent, of γ BHC. This practice has been adopted by the infested estate with successful results in virgins and first ratoons.Further work is suggested on the chemical protection of second and later ratoons by surface application of BHC or aldrin.

Demography and spatial dynamics in balsam fir stands after a spruce budworm outbreak

2011 ◽  
Vol 41 (5) ◽  
pp. 1112-1120 ◽  
Author(s):  
Sergio Rossi ◽  
Hubert Morin
Keyword(s):  
Choristoneura Fumiferana ◽  
Spatial Scales ◽  
Spatial Dynamics ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Permanent Plots ◽  
Random Pattern ◽  
Advance Regeneration ◽  
Competition For Resources

The renewal of balsam fir (Abies balsamea (L.) P. Mill.) stands is related to the recurrent spruce budworm (Archips fumiferana Clemens [syn.: Choristoneura fumiferana (Clemens)]) outbreaks that favour the growth of the regeneration following death of the dominant trees. The aim of this study was to investigate the population demography and the spatial relationships among individuals in four permanent plots of the boreal forest of Quebec, Canada, after a spruce budworm outbreak. This was realized by collecting data on trees and saplings every five years from 1994 to 2004 and by using Ripley’s K statistics. The younger plots showed recruitment of up to 90 new trees·ha–1·year–1, and mortality following competition among individuals affected up to 27% and 50% of the trees and saplings, respectively. In the plot with the lowest tree density, sapling recruitment was estimated as 378 new individuals·ha–1·year–1. Saplings were aggregated at all spatial scales, whereas trees showed a random pattern of stem distribution. A significant tendency to separation between saplings and trees was observed. The specific stand dynamics observed in balsam fir are connected to an abundant advance regeneration and an age-dependent competition for resources in a heterogeneous environment with different levels of resource availability.

A Sampling Technique for Population and Mortality Factors of the Fruit-Tree Leaf Roller, Archips argyrospilus (Wlk.) (Lepidoptera: Tortricidae), on Apple in Quebec

1962 ◽  
Vol 94 (6) ◽  
pp. 561-573 ◽  
Author(s):  
R. O. Paradis ◽  
E. J. LeRoux
Keyword(s):  
Sampling Technique ◽  
Fruit Tree ◽  
Sampling Techniques ◽  
Ecological Studies ◽  
Natural Control ◽  
Mortality Factors ◽  
Leaf Roller ◽  
Control Factors ◽  
Tree Leaf ◽  
Archips Argyrospilus

Sampling techniques for population and mortality factors of the fruit-tree leaf roller, Archips argyrospilus (Wlk.), on apple in Quebec, were developed at Rougemont from 1958 to 1960 with the object of obtaining reliable statistics for life tables on this species. Biometric techniques have not previously been applied for ecological studies of A. argyrospilus, most workers having been primarily concerned with life history, chemical control, and general observations on natural control factors (Gill, 1913; Caesar, 1916 and 1917; Petch, 1916 and 1942; Herrick, 1917; Muesebeck, 1921; Regan, 1923; Viereck, 1924, Venables, 1924 and 1937; Harman, 1928; Hall, 1930 and 1934; Knull, 1932; Chapman et al., 1941; Greenwood, 1943).

scholarly journals Population dynamics of Saissetia oleae. II. Life-tables and key-factor analysis

2017 ◽  
Vol 8 ◽  
pp. 59 ◽  
Author(s):  
E. T. Kapatos ◽  
E.T. Stratopoulou
Keyword(s):  
Factor Analysis ◽  
Population Dynamics ◽  
Population Change ◽  
Life Tables ◽  
Population Fluctuations ◽  
Mortality Factors ◽  
Population System ◽  
Key Factor ◽  
Key Factor Analysis ◽  
Table Data

A series of life-tables for the population of Saisselia oleae (Oliv.) (Homoptera: Coccidae) during five yearly generations (1981-86) were constructed in Corfu. Key-factor analysis carried out on the life-table data indicated that mortality of young stages during summer, caused mainly by the high temperatures, and mortality during spring, caused mainly by predation, determine total population change within each generation. These two mortality factors are the predominant factors of the population dynamics of S. oleae determining population fluctuations. The other mortality factors of the population system of S. oleae were less important. Summer parasites and egg predators, in particular, do not play any significant role on the population dynamics of S. oleae.

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.

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