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.

Artificially Disseminated Virus as a Factor Controlling the European Spruce Sawfly, Diprion hercyniae (Htg.) in the Absence of Introduced Parasites

1961 ◽  
Vol 93 (3) ◽  
pp. 228-238 ◽  
Author(s):  
F. T. Bird ◽  
J. M. Burk
Keyword(s):  
Virus Disease ◽  
Population Trends ◽  
Long Term Effects ◽  
Eastern Canada ◽  
Forest Insect ◽  
Insect Survey ◽  
Forest Biology ◽  
Biology Laboratory ◽  
Disease Free

An outbreak of the European spruce sawfly, Diprion hercyniae (Htg.), occurring in Eastern Canada between 1930 and 1942, was controlled by a virus disease (Balch and Bird, 1944). The sawfly has been kept at a low level by the disease and by parasitic insects introduced from Europe (Bird and Elgee, 1957).An infestation of the sawfly was discovered in 1947 near Sault Ste. Marie, Ontario, by the Forest Insect Survey Section of the Forest Biology Laboratory at Sault Ste. Marie. This infestation was about 100 miles beyond the previously known western distribution of the insect. Intensive larval sampling in 1949 showed that it was free from virus and practically free from introduced parasites. Thus, an excellent opportunity was provided to introduce the virus into a disease-free population, to study its establishment and spread, and to compare the long term effects of virus alone on population trends with the effects that virus plus introduced parasites were shown to have on population trends in New Brunswick (Bird and Elgee, 1957). The virus was introduced into the infestation in 1950 and studies were carried out each year from 1950 to 1959.

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.

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

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.

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.

History of the Larch Sawfly, with Notes on Origin and Biology,

1955 ◽  
Vol 87 (3) ◽  
pp. 103-111 ◽  
Author(s):  
H. C. Coppel ◽  
K. Leius
Keyword(s):  
British Columbia ◽  
North America ◽  
Native Species ◽  
Insect Pest ◽  
Forest Insect ◽  
Larch Sawfly ◽  
History Of ◽  
Biological Characters ◽  
The Difference ◽  
Forest Biology

The larch sawfly, Pristiphora erichronii (Htg.), is currently considered a major forest insect pest in Canada. At the present time within Canada, the sawfly reacts to parasitism by Mesoleius tenthredinis Morley in two ways. In Manitoba and Saslratchewan the sawfly encapsulates approximately 100 per cent of the parasite eggs deposited, whereas in British Columbia encapsulation rarely exceeds four per cent (Muldrew, 1953). The reasons for the difference in degree of encapsulation are apparently unknown; however, since the origin of the sawfly itself is obscure, the possibility exists that a native species, an introduced species, Or a combination of both may he present, or that geographical or ecological units may have arisen. Studies now under way by officers of the Forest Biology and Entomology divisions are attacking the problem of identity and origin following the pattern established for the European spruce sawfly, Diprion hercyniae (Htg.). In this instance, as with the larch sawfly, parasites were introduced on the assumption that the pest had been introduced from Europe. Critical investigations by Reeks (1941) and Balch, Reeks, and Smith (1941), involving morphological, cytological, and other biological characters, showed that the species occurring in North America was one of two species common in Europe, and previously referred to there as Gilpinia polytoma (Htg.). Balch et al. (1941) showed that D. hercyniae had been introduced into North America.

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.

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.

Two New Species of the Genus Hyperaspis (Coleoptera: Coccinellidae)

1960 ◽  
Vol 92 (3) ◽  
pp. 230-234
Author(s):  
W. Y. Watson
Keyword(s):  
New Species ◽  
North America ◽  
Scale Insects ◽  
Eastern North America ◽  
Forest Insect ◽  
Two New Species ◽  
Forest Biology ◽  
Species Descriptions ◽  
Biology Laboratory

Among the more important predacious coccinellids in eastern North America is Hyperaspis binotata auct., which has been considered a general feeder on Toumeyella numismaticum (P. & M.), Pulvinaria spp., and other scale insects. A review of the specimens identified as H. binotata in the collections of the Forest Insect Laboratory, Sault Ste. Marie, has revealed, not only H. binotata (Say), but two apparently new species, descriptions of which are given in this paper. In addition to the material at Sault Ste. Marie, specimens were obtained from the Canadian National Collection and the Forest Biology Laboratory, Winnipeg, Manitoba.

A Survey of Parasites of the Larch Sawfly (Pristiphora erichsonii (Hartig)) in Manitoba and Saskatchewan

1954 ◽  
Vol 86 (8) ◽  
pp. 337-345 ◽  
Author(s):  
R. R. Lejeune ◽  
V. Hildahl
Keyword(s):  
Larix Laricina ◽  
Mountain Area ◽  
Annual Survey ◽  
Northwestern Ontario ◽  
Larch Sawfly ◽  
Forest Biology ◽  
Host Parasite ◽  
Northeastern Alberta ◽  
Biology Laboratory ◽  
Principal Species

Records indicate that the present outbreak of the larch sawfly in Manitoba and Saskatchewan began about 1938 in the Spruce Woods-Riding Mountain area of Manitoba. Since then, it has spread in all directions where the principal host tree, larch, Larix laricina (Du Roi) K. Koch, occurs. It now includes nearly all of Manitoba and Saskatchewan, northwestern Ontario, part of northeastern Alberta, and northern Minnesota. In 1944, an annual survey of parasites that attack larvae of the larch sawfly was begun by the Forest Biology Laboratory, Winnipeg. The purposes of the survey were to determine (a) the principal species of parasites, (b) their abundance and effectiveness, and (c) .host-parasite population trends.

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