An Outbreak of the Larch Sawfly (Pristiphora erichsonii (Htg.)) in the Maritime Provinces (Hymenoptera: Tenthredinidae) and the Role of Parasites in its Control

1954 ◽  
Vol 86 (10) ◽  
pp. 471-480 ◽  
Author(s):  
W. A. Reeks
Keyword(s):  
Prince Edward Island ◽  
Ecological Study ◽  
Maritime Provinces ◽  
Forest Insect ◽  
Staff Members ◽  
The Past ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Insect Survey

At least four outbreaks of the larch sawfly, Pristiphora erichsonii (Htg.), have occurred in the Maritime Provinces within the past 70 years. The first (1) occurred from about 1883 to 1885, the second from about 1906 to 1909 (1), and the third from 1919 to 1927. The last outbreak started in 1933 and ended in 1942. Despite extensive sampling by the Forest Insect Survey from 1943 to 1953, only six samples have been taken during this period in the three Maritime Provinces, and each was an isolated colony. Although an ecological study of the insect was not attempted during the latest outbreak, general observations were made by the writer and other staff members of the Survey. These observations are summarized in the present paper to record the outbreak and some of the factors that contributed to its termination. Another outbreak has persisted in Newfoundland from 1942 and perhaps earlier, but the present discussion is largely confined to events in New Brunswick, Nova Scotia, and Prince Edward Island.

Estimation of Parasitism of Larch Sawfly Cocoons by Bessa harveyi Tnsd. in Survey Collections

1959 ◽  
Vol 91 (8) ◽  
pp. 496-500 ◽  
Author(s):  
W. G. H. Ives ◽  
R. M. Prentice
Keyword(s):  
Forest Insect ◽  
Small Areas ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Insect Survey ◽  
Forest Biology ◽  
Biology Laboratory ◽  
Total Parasitism

The Forest Insect Survey at the Forest Biology Laboratory, Winnipeg, has been compiling records for a number of years on the percentage of cocoons of the larch sawfly, Pristiphora erichsonii (Htg.), parasitized by the tachinid Bessa harveyi Tnsd. Sawfly cocoons were collected each fall from the soil in infested stands, and those containing living larvae were dissected to determine the percentage of parasitism by B. harveyi. These estimates have been used to provide an index of parasitism (Lejeune and Hildahl, 1954), but are of limited value for a number of reasons: (1) estimates can be expressed only as percentage of sound cocoons parasitized; (2) total parasitism cannot be estimated because a portion of the parasites emerge from the cocoons before collection; and (3) estimates of parasitism may not be representative of the stand because there is a tendency to collect cocoons where they are easiest to find; hence all the cocoons in a collection may be from one or two small areas. If the proportion of cocoons containing B. harveyi varies within a stand such collections may give unreliable estimates of parasitism.

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.

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.

BESSA SELECTA (MEIGEN) (DIPTERA: TACHINIDAE) AS A PARASITE OF GILPINIA HERCYNIAE (HARTIG) (HYMENOPTERA: DIPRIONIDAE)

1947 ◽  
Vol 79 (5) ◽  
pp. 84-104 ◽  
Author(s):  
L. S. Hawboldt
Keyword(s):  
High Mortality ◽  
Great Difficulty ◽  
Control Factor ◽  
Forest Insect ◽  
Larch Sawfly ◽  
Insect Survey

This project arose out of studies of the European spruce sawfly, Gilpinia hercyniae (Htg.), in connection with the Canadian Forest Insect Survey at the Dominion Entomological Laboratories, Fredericton, N.B. Bessa selecta (Mg.) had been observed as a parasite of the larch sawfly, Pristiphora erichsoni (Htg.), but particular interest was aroused in it as a parasite occurring on the European spruce sawfly. The latter host was frequently found to bear the eggs and integumental funnels of B. selecta. The object was to study its biology and effectivness as a possible control factor of the spruce sawfly. However, great difficulty was experienced in rearing the host due to high mortality caused by disease. Hence the original aims were not attained to the entire satisfaction of the author.

Storage of Preserved Insect Specimens

1958 ◽  
Vol 90 (8) ◽  
pp. 461-463
Author(s):  
David Evans
Keyword(s):  
Hypodermic Needle ◽  
Air Bubbles ◽  
Forest Insect ◽  
The Past ◽  
Insect Survey ◽  
Forest Biology ◽  
Biology Laboratory ◽  
Small Shell ◽  
Outside Diameter

Several methods of storing insect specimens in liquid preservatives have been used at the Forest Biology Laboratory at Victoria, all of them unsatisfactory to a varying degree. The method described herein was devised by the author and has proved successful during the past year.Homeopathic vials approximately 62 mm. overall outside length × 15 mm. greatest outside diameter × 11 mm. inside neck measurement, with 000 rubber stoppers, are the most suitable size for insect specimens. The different stages of nearly any of the species of insects encountered by the Forest Insect Survey can be easily accommodated in a single vial of this size. Small shell vials may be used for double mounts when tiny insects are involved which might otherwise be lost in the larger vials. For material too large for the 11 mm. neck of the homeopathic vial, shell vials 65 mm. × 15 mm. can be used with serum sleeve-type stoppers. All but mass collections and a few of the larvae can be preserved in these sizes. Both types of rubber stoppers are satisfactory, although the sleeve type requires more effort to put on and seal, and also conceals the top of the vial. Air bubbles can be removed from the latter by inserting a hypodermic needle through the top of the stopper.

HEAT TOLERANCE OF LAST-INSTAR LARVAE OF THE LARCH SAWFLY, PRISTIPHORA ERICHSONII (HYMENOPTERA: TENTHREDINIDAE)

1967 ◽  
Vol 99 (11) ◽  
pp. 1150-1156 ◽  
Author(s):  
R. J. Heron
Keyword(s):  
High Temperature ◽  
Relative Humidity ◽  
Heat Tolerance ◽  
Free Water ◽  
Temperature Acclimation ◽  
Mortality Factor ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Conditioning Temperature

AbstractLaboratory tests of heat tolerance of last-instar larvae of the larch sawfly, Pristiphora erichsonii (Htg.), were made to provide information for the evaluation of the role of high temperature as a mortality factor in field populations.Test larvae were reared from eggs at 21 ± 1.5 °C and 50 ± 10% relative humidity. LT50's were determined at 37°, 39°, 40°, and 41 °C for larvae conditioned at 30 °C and 75% relative humidity.Larvae were less heat resistant during the first 24 hours after molting than they were 24 to 48 hours after molting. The conditioning temperature and the duration of conditioning had very significant effects on heat tolerance. Differences in acclimation due to heat treatment could not be accounted for by differences in free water content.Temperature acclimation will occur in field populations and must be considered in evaluating the role of high temperature as a natural mortality factor.Larvae may encounter lethal temperatures when wandering on branches or tree trunks or crawling on dry ground in open sunshine.

Some Ecological Factors Governing Populations of the Larch Sawfly, Pristiphora erichsonii (Htg.)

1951 ◽  
Vol 83 (6) ◽  
pp. 152-156 ◽  
Author(s):  
R. R. Lejeune
Keyword(s):  
Soil Moisture ◽  
Ecological Factors ◽  
Forest Insect ◽  
Environmental Resistance ◽  
Pristiphora Erichsonii ◽  
Larch Sawfly ◽  
Growth Habits ◽  
Resistance Data

Several ecological factors governing populations of the larch sawfly, Pristiphora erichsonii (Htg.), have been studied in Manitoba and Saskatchewan since the present outbreak began about 1939. It soon became clear that soil moisture, parasires and predators, and the growth habits of tamarack were among the most important components of the environmental resistance. Data from ohservations and experiments were gathered by several investigators of the Forest Insect Laboratory, Winnipeg. Manitoba, and are still largely unpublished. In this paper, an attempt is made to appraise the over-all effect of these factors on abundance of the larch sawfly.

The Bionomics of the Aspen Blotch Miner, Lithocolletis salicifoliella Cham. (Lepidoptera: Gracillariidae)

1956 ◽  
Vol 88 (4) ◽  
pp. 155-168 ◽  
Author(s):  
J. Lynton Martin
Keyword(s):  
Populus Tremuloides ◽  
Trembling Aspen ◽  
Forest Insect ◽  
The Past ◽  
Central Canada ◽  
Insect Survey

The aspen blotch miner, Lithocolletis salicifoliella, Cham., has been abundant on trembling aspen, Populus tremuloides Michx., throughout central Canada for the past few years. The mines of this species are found on the underside of the leaves, and are often abundant enough to cause premature browning of the foliage. This insect first came to the attention of the Forest Insect Survey of Ontario in the vicinity of Lake Nipigon in 1944. By 1950, the infestation covered all but the southern part of Ontario, and was reported in most aspen stands in Manitoba and Saskatchewan. The intensity of the infestation in the northern part of Ontario began to decline by 1952, and in 1954 damage was negligible.

NEW DESCRIPTIONS OF LARVAE OF FOREST INSECTS. INTRODUCTION; I. PANTHEA (LEPIDOPTERA, PHALAENIDAE)

1942 ◽  
Vol 74 (1) ◽  
pp. 8-12 ◽  
Author(s):  
A. W. A. Brown ◽  
W. C. McGuffin
Keyword(s):  
Larval Stage ◽  
Considerable Proportion ◽  
Forest Insect ◽  
The Past ◽  
Forest Insects ◽  
Insect Survey

During the past five years several thousand samples of lepidopterous larvae have been collected from spruce in the course of the Canadian Forest Insect Survey (1). It was found that a considerable proportion of the species had been hitherto unknown in the larval stage, and that many others had been only briefly or superficially described. In this paper, and in subsequent instalments, descriptions will be presented for those species whose larvae, to the author's knowledge, have never been described before.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

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