Mortality of Cocoons of the Larch Sawfly, Pristiphora erichsonii (Htg.), in Relation to Distance from Small-Mammal Tunnels

1959 ◽  
Vol 91 (9) ◽  
pp. 535-542 ◽  
Author(s):  
C. H. Buckner
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Natural Mortality ◽  
Mortality Factors ◽  
Forest Reserve ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
The Relationship

The relationship between the fate of cocoons of the larch sawfly, Pristiphora erichsonii (Htg.), and distance from small-mammal tunnels was studied during 1958 in the Whiteshell Forest Reserve of eastern Manitoba. The objects were to determine the distance that small mammals can detect cocoons and to observe possible effects of the interactions of small-mammal predation and other natural mortality factors of the insect. Additional analyses of the data provided information on the behaviour of the predators and the ecology of the prey insect.

The Assessment of Larch Sawfly Cocoon Predation by Small Mammals

1959 ◽  
Vol 91 (5) ◽  
pp. 275-282 ◽  
Author(s):  
C. H. Buckner
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Life Tables ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Forest Biology ◽  
Biology Laboratory ◽  
Adequate Method

Current investigations at the Forest Biology Laboratory, Winnipeg, are being directed towards the formulation of life tables for the larch sawfly, Pristiphora erichsonii (Htg.) (Lejeune, 1955). Because small mammal predation is a major factor in reducing cocoon populations of the sawfly (Buckner, 1953), an adequate method of assessing this source of mortality is desirable

A Sequential Sampling Technique for Surveys of the Larch Sawfly

1958 ◽  
Vol 90 (6) ◽  
pp. 331-338 ◽  
Author(s):  
W. G. H. Ives ◽  
R. M. Prentice
Keyword(s):  
Sampling Methods ◽  
Population Studies ◽  
Sequential Sampling ◽  
Sampling Technique ◽  
Large Sample Size ◽  
Forest Reserve ◽  
Forest Insects ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly

Sequential sampling methods have been developed for population surveys of a number of forest insects (4, 6, 7, 9). These methods permit rapid classification of populations into broad infestation classes with predetermined accuracy and a minimum of sampling, and are useful for mapping and recording widespread infestations.The method of assessing egg populations of the larch sawfly, Pristiphora erichsonii (Htg.), developed by Ives (3) for intensive population studies, was not suitable for surveys because of the large sample size required. A sequential plan for the larch sawfly using hypothetical infestation classes was briefly reviewed by Ives (2). This plan is modified in the present paper in accordance with new data that have accumulated from observations on plots in the Whiteshell Forest Reserve and other stands in Manitoba and Saskatchewan.

Population Dynamics of the Larch Sawfly

1964 ◽  
Vol 96 (1-2) ◽  
pp. 160-161 ◽  
Author(s):  
Keyword(s):  
Biological Control ◽  
Population Dynamics ◽  
Life Table ◽  
Quantitative Methods ◽  
Population Data ◽  
Natural Control ◽  
Mortality Factors ◽  
Ecological Relationships ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly

The larch sawfly, Pristiphora erichsonii (Htg.), has been studied in Manitoba for over 50 years, since the first outbreaks led to the introduction of the European parasite, Mesoleius tenthredinis Morley. This parasite was credited with reducing the severity of early outbreaks but when host populations again increased in the early 1940's, it was found that M. tenthredinis was ineffective due to the ability of host larvae to encapsulate parasite eggs. Intensive studies of individual mortality factors were initiated at the Winnipeg Laboratory as staff and facilities were expanded in the late 1940's. Development of the life-table concept of recording population data (Morris and Miller 1954) led to co-ordination of several projects until by 1955 a team of research officers was engaged in comprehensive studies of general ecological relationships, parasitism, vertebrate predation, and the effect of defoliation on host stands. Members of the team currently engaged in population dynamics studies and responsible for this exhibit are: Dr.C. H. Buckner, vertebrate predators; W. G. H. Ives, quantitative methods and natural control; L. D. Nairn, interrelations with host tree; Dr. W. J. Turnock, natural and biological control, bioclimatology. Other Winnipeg officers working on related larch sawfly projects are Dr. R. J. Heron, physiological studies, and J. A. Muldrew, biological control with particular reference to immunity to M. tenthredinis.

Estimation of Adult Populations of the Larch Sawfly, Pristiphora erichsonii (Htg.)

1960 ◽  
Vol 92 (9) ◽  
pp. 659-662 ◽  
Author(s):  
W. J. Turnock
Keyword(s):  
Mortality Factors ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly

This paper is one in a series on techniques for estimating populations of various stages of the larch sawfly (Ives, 1055; Ives and Prentice, 1958; Ives and Turnock, 1959) to provide's basis for the evaluation of mortality factors. The larch sawfly overwinters in a cocoon in the soil and adults emerge during the spring and summer (Turnock, 1960). This paper describes the methods and results of sampling adults as they emerge from the soil.

History of Larch Sawfly Outbreaks and their Effect on Tamarack Stands in Manitoba and Saskatchewan

1962 ◽  
Vol 94 (3) ◽  
pp. 242-255 ◽  
Author(s):  
L. D. Nairn ◽  
W. A. Reeks ◽  
F. E. Webb ◽  
V. Hildahl
Keyword(s):  
Life Table ◽  
Annual Reports ◽  
Forest Insect ◽  
Forest Reserve ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
History Of ◽  
Insect Survey

The larch sawfly, Pristiphora erichsonii (Htg.), has been under observation in Manitoba and Saskatchewan since early in the present century. Recorded observations were somewhat fragmentary until 1937; since then systematic and detailed annual reports have been provided by the Forest Insect Survey and since 1948 intensive ecological and life table studies have been conducted by staff of the Winnipeg Laboratory at the Whiteshell Forest Reserve, Manitoba.

Estimation of Cocoon Populations of the Larch Sawfly, Pristiphora erichsonii (Hartig)

1959 ◽  
Vol 91 (10) ◽  
pp. 650-661 ◽  
Author(s):  
W. G. H. Ives ◽  
W. J. Turnock
Keyword(s):  
Soil Sampling ◽  
The Other ◽  
Host Tree ◽  
Accurate Estimation ◽  
Mortality Factors ◽  
Factors Affecting ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly

This paper is one in a series on techniques used in estimating populations of various stages of the larch sawfly (Ives, 1955b; Ives and Prentice, 1958). This insect spends most of the year in cocoons in the soil beneath the host tree. The objective of accurate estimation of the cocoon population is to provide a basis for the evaluation of mortality factors affecting this stage. Two methods of estimation are considered in this paper. One is based on soil sampling (Part I) and the other on the number of cocoons formed in traps for falling larvae (Part 11).

An 11-year study of small mammal populations at Mont St. Hilaire, Quebec

1976 ◽  
Vol 54 (12) ◽  
pp. 2156-2173 ◽  
Author(s):  
P. R. Grant
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Sugar Maple ◽  
Deciduous Forest ◽  
Beech Forest ◽  
Microtus Pennsylvanicus ◽  
Blarina Brevicauda ◽  
The Relationship ◽  
Range Of Variation ◽  
Relevant Factors

Mont St. Hilaire has an area of about 10 km2 covered by sugar maple and beech forest. Longworth traps were used on 46 grids from 1966 to 1976 in the snow-free period, mainly in June. One thousand and fifty-one individuals of 10 species of small mammals were captured. Two-thirds of these were Peromyscus, mainly P. maniculatus. Six female and one male Microtus pennsylvanicus were captured, all at least 1000 m from the nearest grassland, which is the usual habitat of this species.Within the forest the species apparently do not segregate into different habitats. Distribution, as measured by the number of grids on which each species was captured, is a function of total numbers. The relationship holds intraspecifically and interspecifically. Peromyscus (species combined), Clethrionomys gapperi, and Blarina brevicauda varied in June numbers from year to year. The range of variation was greatest for Peromyscus. Numbers of Peromyscus and Clethrionomys did not vary synchronously, and neither showed evidence of a regular periodicity in their fluctuations. Regular periodicity in fluctuations appears to be more prevalent in boreal forest populations than in deciduous forest populations. Some of the relevant factors are discussed.Le Mont Saint-Hilaire a une superficie d'environ 10 km2 et est recouvert d'une forêt d'érables à sucre et de hêtres. On a utilisé des pièges Longworth dans 46 sections d'un quadrillage, de 1966 à 1976, durant la période sans neige, surtout en juin. On a recueilli de cette façon 1051 petits mammifères appartenant à 10 espèces. Les deux-tiers de ces animaux appartiennent au genre Peromyscus, et ce sont surtout des P. maniculatus. Six femelles et un mâle de Microtus pennsylvanicus ont été capturés, tous à au moins 1000 m de la prairie la plus proche, environnement habituel de cette espèce.

Developmental Rates of Larch Sawfly (Pristiphora erichsonii (Htg.)) Larvae in an Insectary and in Field Shelters

1960 ◽  
Vol 92 (9) ◽  
pp. 668-674 ◽  
Author(s):  
W. G. H. Ives
Keyword(s):  
Larval Development ◽  
Life Histories ◽  
Field Data ◽  
Forest Reserve ◽  
Sawfly Larvae ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Developmental Rates

In 1959 a study was conducted in the Whiteshell Forest Reserve, Manitoba, to determine if insectary-reared larch sawfly larvae developed at the same rate as in the field. Data were collected on the rate of frass production in both situations and used as an index of larval development. This was part of a broader study that will be reported on more fully in a later publication, but the immediate results should be of interest to those concerned with studies on ecological life histories of other insects.

ESTIMATION OF EGG POPULATIONS OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HTG.)

1955 ◽  
Vol 33 (5) ◽  
pp. 370-388 ◽  
Author(s):  
W. G. H. Ives
Keyword(s):  
Frequency Distribution ◽  
Additional Data ◽  
Simple Random Sampling ◽  
Larix Laricina ◽  
Forest Reserve ◽  
Proportional Allocation ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
The Mean ◽  
Number Of Branches

The larch sawfly, Pristiphora erichsonii (Htg.), lays its eggs in the new terminal shoots of tamarack, Larix laricina (Du Roi) K. Koch. The oviposition injury usually causes the shoots to curl. During 1952 a sampling project was conducted in the Whiteshell Forest Reserve, Manitoba, to determine the feasibility of sampling tamarack trees to obtain estimates of the egg population of the larch sawfly. Additional data on the frequency distribution of the number of larch sawfly eggs per shoot were collected in 1953 and 1954 from several areas in Manitoba and Saskatchewan. The number of eggs per curled tip varied between plots and between trees on one plot, but no factors contributing to variation could be found. The frequency distribution of the number of eggs per curled shoot was found to be a modified logarithmic normal distribution. The number of curled tips per branch and the number of branches per crown level varied between crown levels and between tree types. Stratification of the sample increased the efficiency of sampling, reducing the standard error of the mean by about 15% and the required sample size by about 30%. The large variation in the estimated number of curled tips per tree indicates that a large sample of trees is required to obtain accurate estimates. As a compromise between accuracy and practicability it is recommended that six-branch samples be taken from each of at least 15 trees, using stratified sampling with proportional allocation. Simple random sampling, taking two branches from the mid-crown of at least 25 trees, is suggested to provide a population index of sufficient accuracy for survey purposes.

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