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.

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.

VITAL DYES AS MARKERS FOR BEHAVIORAL AND POPULATION STUDIES OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE)

1968 ◽  
Vol 100 (5) ◽  
pp. 470-475 ◽  
Author(s):  
R. J. Heron
Keyword(s):  
Rhodamine B ◽  
Population Studies ◽  
Nile Blue ◽  
Larix Laricina ◽  
Vital Dyes ◽  
Flight Range ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Adult Dispersal ◽  
Dye Retention

AbstractLarvae of the larch sawfly, Pristiphora erichsonii (Htg.), were fed foliage of tamarack, Larix laricina (Du Roi) K. Koch, treated with solutions of the vital dyes, Nile blue sulphate, rhodamine B, and coriphosphine O, to determine their suitability as markers. Coriphosphine O was highly toxic at the concentrations administered but successful tagging was obtained with the other two dyes. Optimal dye retention and survival were obtained when larvae were fed for 3 days early in the last stadium using Nile blue sulphate and throughout the last stadium using rhodamine B.Both dyes persisted throughout development and were incorporated in the cocoons and the oviposited eggs. They could be readily seen in all stages except for the cocoons and for eggs that contained rhodamine B. The dyes could be detected in cocoons by treating them with cold KOH followed by ethanol. The presence of rhodamine B in the eggs could be ascertained by its yellow fluorescence in ultraviolet.The dyes incorporated in the cocoons are relatively stable and laboratory tests indicate they probably can withstand weathering under normal field conditions over a 1-year period.The use of these dyes for internal marking should prove useful in studying adult dispersal and flight range and as a technique for use in population studies of the larch sawfly.

A Strain of Bacillus cereus Fr. and Fr. Pathogenic for the Larch Sawfly, Pristiphora erichsonii (Htg.)

1954 ◽  
Vol 86 (2) ◽  
pp. 73-77 ◽  
Author(s):  
A. M. Heimpel
Keyword(s):  
Bacillus Cereus ◽  
Field Experiments ◽  
Positive Correlation ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
The Mean

AbstractA strain of Bacillus cereus (Pr-1017) was isolated from dead and dying larvae of the larch sawfly. Laboratory and field feeding tests resulted in mortalities as high as 60 per cent and 38 per cent, respectively.A positive correlation between the incidence of mortality and the mean daily temperatures was obtained in the field experiments.

HEAD CAPSULE MEASUREMENTS OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE) IN KOUCHIBOUGUAC NATIONAL PARK, NEW BRUNSWICK

1980 ◽  
Vol 112 (1) ◽  
pp. 111-112 ◽  
Author(s):  
Patrick Maltais
Keyword(s):  
New Brunswick ◽  
Prince Edward Island ◽  
National Park ◽  
Developmental Stages ◽  
Head Capsule ◽  
Larix Laricina ◽  
Maritime Provinces ◽  
Eastern Canada ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly

The larch sawfly, Pristiphora erichsonii (Htg.), is a serious defoliator of trees of the genus Larix and particularly of Larix laricina (Du Roi) K. Koch in eastern Canada. According to Reeks (1954), four outbreaks occurred in the Maritime Provinces between 1883 and 1942. Following the last outbreak, few specimens of the insect were found in New Brunswick, Nova Scotia, and Prince Edward Island until 1960 when an outbreak started near Fredericton, New Brunswick. Since, outbreaks varying in degree from moderate to severe have persisted throughout this province.In the course of a study on the ecology and population dynamics of the insect it was found necessary to verify and separate the various developmental stages of the larvae.

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.

RECENT OUTBREAK OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HARTIG), IN SUBARCTIC QUÉBEC

1991 ◽  
Vol 123 (3) ◽  
pp. 611-619 ◽  
Author(s):  
Conrad Cloutier ◽  
Louise Filion
Keyword(s):  
General Characteristic ◽  
Climatic Conditions ◽  
Population Increase ◽  
Larix Laricina ◽  
Sudden Increase ◽  
Frequency Distributions ◽  
Pristiphora Erichsonii ◽  
Shoot Production ◽  
Larch Sawfly ◽  
Long Shoots

AbstractLarch sawfly oviposition activity as revealed by scarring of long shoots of eastern larch, Larix laricina (DuRoi) K. Koch, was measured at various locations in the high boreal forest and forest tundra in Québec in 1988 and 1989. The data show that larch sawfly is established up to the tree line, even on isolated larch growing under climatic conditions that are extreme for this tree. Frequency distributions of scarred shoots as a function of time suggest thai larch sawfly populations reached outbreak levels in the 1980s, with peak numbers in 1981 for the high boreal, and in 1985 for the subarctic regions sampled. Trends in long shoot production by larch trees started to fluctuate simultaneously with the sudden increase in larch sawfly populations along the Grande Rivière de la Baleine in 1984. In this region in 1985, the proportion of long shoots used by Pristiphora erichsonii averaged 20–35%, which may have limited further population increase. Although foliage reduction and branch mortality were observed, mortality of whole trees was not a general characteristic of this outbreak.

HOST DERIVED CHEMICALS: THE BASIS FOR PREFERENTIAL FEEDING BEHAVIOR OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE), ON TAMARACK, LARIX LARICINA

1979 ◽  
Vol 111 (2) ◽  
pp. 165-169 ◽  
Author(s):  
M. R. Wagner ◽  
T. Ikeda ◽  
D. M. Benjamin ◽  
F. Matsumura
Keyword(s):  
Thin Layer ◽  
Feeding Behavior ◽  
Larix Laricina ◽  
Distilled Water ◽  
Sawfly Larvae ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Short Shoots ◽  
Layer Chromatography ◽  
Preferential Feeding

AbstractLarch sawfly larvae, Pristiphora erichsonii (Hartig), naturally reject single needles of newly elongated shoots and consume only tufted foliage from 1 year or older short shoots of tamarack, Larix laricina (Du Roi) K. Koch. Forest entomologists have recognized this unusual feeding behavior for over a century, but not until now has the mechanism been understood. In the bioassasy of unpurified single needle methanol extracts (concn. 1 g needle/ml), 88.5% of the larvae were feeding on the control end of the bioassay twig (solvent only) after 4 h. This was significantly different from a similar bioassay of tufted foliage extract (t-value significant at 0.02 level) and a non-treated control bioassay (distilled water on both ends of bioassay twig) (t-value significant at 0.01 level). In the bioassay of a purified extract of single tamarack needles (TLC fraction 7), 81% of larvae were feeding on the untreated end (t-value significant 0.02). Thin-layer chromatography fraction 7, of eight fractions delineated, alone induced significant feeding inhibition.

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.

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