CARPENTER ANTS AS PREDATORS OF SPRUCE BUDWORM IN THE BOREAL FOREST OF NORTHWESTERN ONTARIO

1992 ◽  
Vol 124 (6) ◽  
pp. 1093-1100 ◽  
Author(s):  
C.J. Sanders ◽  
A. Pang
Keyword(s):  
Boreal Forest ◽  
Boreal Forests ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Western North America ◽  
Tree Crown ◽  
Carpenter Ants ◽  
Northwestern Ontario ◽  
Large Numbers ◽  
Laboratory Colony

AbstractIn the boreal forest of northwestern Ontario, where carpenter ants (Camponotus spp.) construct extensive underground tunnels, few worker ants were seen on the aerial portions of trees containing colonies of the ants or on neighboring trees, even though the trees were infested by large numbers of spruce budworm [Choristoneura fumiferana (Clem.)] larvae. Immunochemical techniques detected less spruce budworm soluble protein in worker ants from this area than in a laboratory colony that had been fed budworm larvae, or in a colony located in a spruce tree that was surrounded by gravel where the ants were unable to build underground tunnels and instead foraged extensively in the tree crown. This suggests that, in contrast to evidence from western North America, carpenter ants in the boreal forests of northwestern Ontario, and perhaps elsewhere throughout the range of the spruce budworm, are of limited importance as predators of the spruce budworm.

A Relation Between April and May Temperatures and Spruce Budworm Larval Emergence

1954 ◽  
Vol 86 (4) ◽  
pp. 174-177 ◽  
Author(s):  
A. H. Rose ◽  
J. R. Blais
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Apparent Temperature ◽  
Temperature Threshold ◽  
Northwestern Ontario ◽  
Large Numbers ◽  
Larval Emergence ◽  
Sudden Appearance ◽  
Spring Temperatures ◽  
Four Square

In the spring, spruce budworm (Choristoneura fumiferana (Clem)), emerge as second-instar larvae from hibernacula. This emergence may be sudden and is readily detectable in the field. In northwestern Ontario, the sudden appearance of larvae in large numbers was especially spectacular in 1948; that year, very few insects were observed on May 11, but on the following two days, countless larvae could be seen on strands of silk streaming out from trees. Many of the insects were carried away by air currents. The surface of Big Canon Lake, a body of water close to four square miles in area, was covered with larvae, at an estimated density of 100 larvae per square foot of surface. At other times, however, emergence may be gradual or there may be two distinct periods of abundant emergence. Furthermore, the time of abundant larval emergence through six years has varied by as much as four weeks. Because of such differences, prevailing spring temperatures were examined to determine what relationship might exist between temperature and the time and character of emergence. This paper points out a relationship between emergence and April and May temperatures, and an apparent temperature threshold for emergence.

Derivation of Pheromone-Based Larval Thresholds in Spruce Budworm Accounting for Distance to Defoliated Forest Stands

2021 ◽  
Author(s):  
Marc Rhainds ◽  
Ian DeMerchant ◽  
Pierre Therrien
Keyword(s):  
Boreal Forests ◽  
Large Scale ◽  
Choristoneura Fumiferana ◽  
Intervention Strategy ◽  
Spruce Budworm ◽  
Interactive Effects ◽  
The Novel ◽  
Forest Stands ◽  
General Guideline ◽  
Number Of Males

Abstract Spruce budworm, Choristoneura fumiferana Clem. (Lepidoptera: Tortricidae), is the most severe defoliator of Pinaceae in Nearctic boreal forests. Three tools widely used to guide large-scale management decisions (year-to-year defoliation maps; density of overwintering second instars [L2]; number of males at pheromone traps) were integrated to derive pheromone-based thresholds corresponding to specific intergenerational transitions in larval densities (L2i → L2i+1), taking into account the novel finding that threshold estimates decline with distance to defoliated forest stands (DIST). Estimates of thresholds were highly variable between years, both numerically and in terms of interactive effects of L2i and DIST, which limit their heuristic value. In the context of early intervention strategy (L2i+1 > 6.5 individuals per branch), however, thresholds fluctuated within relatively narrow intervals across wide ranges of L2i and DIST, and values of 40–200 males per trap may thus be used as general guideline.

AN IMPROVED METHOD FOR PRODUCING LARGE NUMBERS OF SECOND-INSTAR SPRUCE BUDWORM LARVAE, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1972 ◽  
Vol 104 (12) ◽  
pp. 1955-1957 ◽  
Author(s):  
Dail Grisdale
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Immature Stages ◽  
Improved Method ◽  
Physical Conditions ◽  
Large Numbers

AbstractA method for weekly production in excess of 100,000 second-instar larvae of the spruce budworm, Choristoneura jumiferana (Clem.), is described. It depends on adherence to specific regimes of physical conditions and manipulation for the different immature stages. Standard, easily obtained utensils and materials are used in the rearing technique.

Lepidoptera wing scales: a new paleoecological indicator for reconstructing spruce budworm abundance

2018 ◽  
Vol 48 (3) ◽  
pp. 302-308 ◽  
Author(s):  
Lionel Navarro ◽  
Anne-Élizabeth Harvey ◽  
Hubert Morin
Keyword(s):  
Boreal Forest ◽  
Fire History ◽  
Choristoneura Fumiferana ◽  
Sediment Cores ◽  
Spruce Budworm ◽  
Natural Disturbances ◽  
Original Approach ◽  
Size Scales ◽  
Forest Landscape Dynamics ◽  
Wing Scales

Natural disturbances have a major impact on boreal forest landscape dynamics, and although fire history is well documented at the Holocene scale, spruce budworm (Choristoneura fumiferana (Clemens)) (SBW) dynamics have only been known for the last three centuries. This is likely due to the difficulty in using and interpreting existing indicators (cephalic head capsules and feces). In this methodological study, we present an original approach using lepidopteran wing scales to reconstruct insect abundance. We analyzed two sediment cores from the boreal forest in central Quebec and extracted wing scales at every stratigraphic level. The required quantity of sediment for paleoecological analysis is relatively small given the large quantity of wing scales produced by Lepidoptera and their small size. Scales are well preserved due to their chitinous structure and their great variety of shapes offer a high potential for taxonomic identification. A statistical model based on the shape of scales of the three major epidemic lepidopterans in Quebec discriminated 68% of SBW scales. This indicator allows a more efficient and more precise reconstruction of SBW history with respect to the use of cephalic head capsules or feces.

scholarly journals Wolverine, Gulo gulo, Home Range Size and Denning Habitat in Lowland Boreal Forest in Ontario

2010 ◽  
Vol 124 (2) ◽  
pp. 139 ◽  
Author(s):  
F. Neil Dawson ◽  
Audrey J. Magoun ◽  
Jeff Bowman ◽  
Justina C. Ray
Keyword(s):  
Home Range ◽  
Boreal Forest ◽  
Boreal Forests ◽  
Radio Telemetry ◽  
Habitat Type ◽  
Home Range Size ◽  
Home Ranges ◽  
Minimum Convex Polygon ◽  
Northwestern Ontario ◽  
Selection Of

We conducted the first radio-telemetry study of Wolverines in northwestern Ontario during the winter of 2003-2004 to determine whether home ranges and movements of Wolverines in lowland boreal forest were typical of this species in other ecosystems and to describe reproductive den sites in this habitat type. Seven Wolverines (3 M, 4 F) were radio-tagged and monitored for 31 to 269 (Mean ± SE = 153 ± 35) days using a combination of remotely monitored Argos satellite and conventional aerial telemetry. Male and female 95% minimum convex polygon (MCP) home ranges (±SE) during December to October were 2,563 (796) km2 and 428 (118) km2, respectively, for combined VHF and Argos locations. A lactating female had a 95% MCP home range of 262 km2. The den site for this female included large boulders and downed trees, similar to dens described for this species in montane ecosystems. Boulder complexes and downed trees may be critical features of wolverine dens in lowland boreal forests. Mean road densities (± SE) within 95% MCP and 50% MCP home ranges were 0.43 (0.13) and 0.33 (0.23) km/km2, respectively, and our results suggest that road densities may affect selection of home ranges by Wolverines. The Wolverine population was a resident, reproductive population. Erratum for table included.

scholarly journals Vulnerability of Conifer Regeneration to Spruce Budworm Outbreaks in the Eastern Canadian Boreal Forest

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 850 ◽  
Author(s):  
Janie Lavoie ◽  
Miguel Montoro Girona ◽  
Hubert Morin
Keyword(s):  
Boreal Forests ◽  
Black Spruce ◽  
Choristoneura Fumiferana ◽  
Management Strategies ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Balsam Fir ◽  
Insect Outbreaks ◽  
Spruce Stands ◽  
Canadian Boreal Forest

Spruce budworm (Choristoneura fumiferana) is the main defoliator of conifer trees in North American boreal forests, affecting extensive areas and causing marked losses of timber supplies. In 2017, spruce budworm affected more than 7 million ha of Eastern Canadian forest. Defoliation was particularly severe for black spruce (Picea mariana (Mill.) B.S.P.), one of the most important commercial trees in Canada. During the last decades, intensive forest exploitation practices have created vast stands of young balsam fir (Abies balsamea (L.) Mill.) and black spruce. Most research focused on the impacts of spruce budworm has been on mature stands; its effects on regeneration, however, have been neglected. This study evaluates the impacts of spruce budworm on the defoliation of conifer seedlings (black spruce and balsam fir) in clearcuts. We measured the cumulative and annual defoliation of seedlings within six clearcut black spruce stands in Quebec (Canada) that had experienced severe levels of defoliation due to spruce budworm. For all sampled seedlings, we recorded tree species, height class, and distance to the residual forest. Seedling height and species strongly influenced defoliation level. Small seedlings were less affected by spruce budworm activity. As well, cumulative defoliation for balsam fir was double that of black spruce (21% and 9%, respectively). Distance to residual stands had no significant effect on seedling defoliation. As insect outbreaks in boreal forests are expected to become more severe and frequent in the near future, our results are important for adapting forest management strategies to insect outbreaks in a context of climate change.

THIOTEPA AS AN EFFECTIVE AGENT FOR MASS STERILIZING THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1971 ◽  
Vol 103 (12) ◽  
pp. 1753-1756 ◽  
Author(s):  
Arthur Retnakaran
Keyword(s):  
Adverse Effects ◽  
Topical Application ◽  
Adult Male ◽  
Filter Paper ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Effective Agent ◽  
Diffusion Pump ◽  
Large Numbers ◽  
And Diffusion

AbstractTopical application of thiotepa on the adult male spruce budworm, Choristoneura fumiferana Clemens, at a concentration of 10 μg/insect resulted in 100% sterility. Unlike metepa, thiotepa did not have any apparent adverse effects on the competency of the sperms. Large numbers of male moths can be sterilized by allowing them to walk for 30 min on filter paper treated with a 2.5% solution of thiotepa in a 3:1 mixture of acetone and diffusion pump oil.

Partial windthrow as a driving process of forest dynamics in old-growth boreal forests

2014 ◽  
Vol 44 (10) ◽  
pp. 1165-1176 ◽  
Author(s):  
François Girard ◽  
Louis De Grandpré ◽  
Jean-Claude Ruel
Keyword(s):  
Boreal Forest ◽  
Forest Dynamics ◽  
Boreal Forests ◽  
Tree Mortality ◽  
Stand Structure ◽  
Temporal Dynamics ◽  
Spruce Budworm ◽  
Climatic Conditions ◽  
Balsam Fir ◽  
Vegetation Development

As climate changes, boreal forest ecosystems may become subject to disturbances that were previously uncommon in some regions. In recent decades, large tracts of northeastern boreal forest of Canada have been affected by different types of climatic events causing a lot of partial and some total stand mortality. Since these disturbances may become more important drivers of forest dynamics, there is a need to document their impact on forest structure. The objectives of this study were to describe temporal dynamics of partial windthrows and determine the effect of partial windthrow on stand composition and understory vegetation. The study was conducted in the North-Shore region of Quebec (Canada). Eighteen plots in closed forests were paired with 18 adjacent windthrow areas, in which trees experienced similar edaphic and climatic conditions. Dendroecological analyses, combined with vegetation sampling, were conducted on each site to determine stand structure and vegetation development through time. Significant increases in balsam fir and shade-tolerant species were observed in windthrow gaps. Tree mortality in windthrown stands was a slow process until the mid-1990s, a period during which spruce budworm defoliation may have played a role in weakening trees and making them more vulnerable to partial windthrow. Greater mortality observed following the mid-1990s was most certainly related to a regional storm. The initial composition of stands plays an important role in driving postwindthrow succession, as balsam fir is more susceptible to treefall. As opposed to stand-replacing windthrow and spruce budworm outbreaks that generate various postdisturbance responses, partial windthrow appears to only create opportunities for pre-established balsam fir to undergo release in gaps.

A SIMPLE TECHNIQUE FOR INDEXING THE MATING STATUS OF MALE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1986 ◽  
Vol 118 (1) ◽  
pp. 37-41 ◽  
Author(s):  
J.C. Bergh ◽  
W.D. Seabrook
Keyword(s):  
Simple Technique ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Reliable Index ◽  
Mating Status ◽  
Yellow Substance ◽  
Laboratory Colony ◽  
Unmated Male

AbstractSection 7 of the primary simplex of the ductus ejaculatorius of unmated male spruce bud worm moths, Choristoneura fumiferana, contains a yellow substance that is not present in recently mated males. The yellow substance occurs in laboratory-colony males reared on diet and in feral males reared on foliage. It is shown that the presence/absence of this material is a reliable index of copulation during the previous 24 h. Although the yellow substance regenerates over a period of several days, males 0–72 h post-copulation may be indexed when compared with unmated males of similar age.

Spruce Budworm Parasite Studies in Northwestern Ontario

1959 ◽  
Vol 91 (12) ◽  
pp. 758-783 ◽  
Author(s):  
B. M. McGugan ◽  
J. R. Blais
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Senior Author ◽  
The West ◽  
Northwestern Ontario ◽  
Junior Author ◽  
Limited Basis ◽  
The University ◽  
Parasite Complex ◽  
General Influence

The extensive coniferous stands in northwestern Ontario have been subjected to repeated widespread outbreaks of the spruce budworm, Choristoneura fumiferana (Clem.) (5). About 1939 two such outbreaks originated almost simultaneously, one on the west shores of Lake Nipigon and the other south of Lac Seul approximately 180 miles farther west. Each outbreak eventually covered thousands of square miles and was responsible for the destruction of hundreds of square miles of balsam fir forest. Studies of the parasite complex attacking the spruce budworm in northwestern Ontario and the assessment of its general influence on budworm population trends were initiated in the Lake Nipigon outbreak in 1946 by Professor N. R. Brown, now of the University of New Brunswick, and were further developed by the senior author from 1947 to 1950. Similar investigations were initiated by the junior author in the Lac Seul outbreak in 1950 and continued until 1954. Studies in both areas were continued on a limited basis until 1956 through the co-operation of several research officers.

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