scholarly journals Bottom-up factors contribute to large-scale synchrony in spruce budworm populations

2018 ◽  
Vol 48 (3) ◽  
pp. 277-284 ◽  
Author(s):  
Mathieu Bouchard ◽  
Jacques Régnière ◽  
Pierre Therrien
Keyword(s):  
Large Scale ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Trophic Factors ◽  
Population Fluctuations ◽  
Bottom Up ◽  
Cone Production ◽  
Climate Change Effects ◽  
Phenological Mismatch ◽  
Insect Populations

Understanding the mechanisms that cause large-scale synchrony in insect population dynamics might yield key insights for predicting potential outbreak occurrence. Here, we evaluated which environmental factors best explain synchronous population fluctuations in the spruce budworm (Choristoneura fumiferana Clem.) (SBW), a major defoliator of coniferous forests in North America. SBW population levels were assessed with pheromone traps during the 1986–2014 period across a 625 000 km2 territory located in the province of Québec (Canada). The populations were characterized by abundance fluctuations that were often synchronized across the whole study area. Interannual population fluctuations were correlated with host tree cone production (a source of food) and high May temperatures, suggesting that synchrony was influenced by food availability and phenological mismatch during shoot development. Cone production was itself correlated with low precipitation during the previous summer. This study indicates that bottom-up trophic factors can drive spatiotemporal synchrony in insect populations and contribute to explain important and sustained population increases during some years. We also suggest that several biological processes, all influenced by weather, are likely to interact to explain population synchrony during the different phases of the approximately 35 year SBW outbreak cycle, complicating the prediction of climate change effects on this insect.

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.

Evidence of DDT Resistance in Populations of Spruce Budworm, Choristoneura fumiferana (Clem.), From DDT-sprayed Areas of New Brunswick

1965 ◽  
Vol 97 (12) ◽  
pp. 1281-1293 ◽  
Author(s):  
A. P. Randall
Keyword(s):  
New Brunswick ◽  
Large Scale ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Data Interpretation ◽  
Fuel Oil ◽  
Susceptible Population ◽  
Mortality Curve ◽  
Progressive Development ◽  
Ddt Resistance

AbstractA series of laboratory toxicological experiments using various concentrations of oil formulated DDT solutions (AR-50/fuel oil (2:7 V/V)) was carried out on 5th and 6th instar spruce budworm larvae collected in the field from DDT-sprayed and untreated areas of New Brunswick, Canada, and Maine, U.S.A.Results obtained in 1959, 1961, and 1962 with larvae collected from isolated, unsprayed areas in New Brunswick showed a consistent, straight log-dosage probit mortality curve. Larvae collected in 1962 and 1963 from infestation centres previously subjected to three, four, and five applications of non-consecutive large-scale aerial sprays of DDT showed a significant departure from the straight log-dosage probit curve previously obtained. The departure occurs as a change in the shape of the curve as well as a shift to the higher concentration range of DDT. The magnitude of change appears to be correlated with the number of sprays to which the population was exposed. Results obtained in 1962 and 1963, from untreated control and inter-spray areas, bounded by DDT-sprayed forest lands, showed a small but significant departure from the normal straight probit line of a susceptible population. These changes are indicative of a progressive development of DDT resistance in wild populations of spruce budworm.Studies on the effect of the tolerance of spruce budworm larvae within instar classes to the action of DDT showed that the early phase of instar development immediately after moulting is more susceptible to the action of DDT, whereas the latter phase of instar development immediately prior to moulting is more tolerant to topical application of DDT than the average for the instar. This effect is evident in both susceptible and resistant populations.The data interpretation assumes that a deviation from the straight line probit dosage – mortality curve is indicative of a difference in the DDT-susceptibility factor of the budworm population and that in the course of the tests, the amount of toxicant causing mortality was not proportional to the dosage.

SOIL APPLICATION OF CARBOFURAN TO CONTROL SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE), IN A MANAGED WHITE SPRUCE SEED PRODUCTION AREA

1981 ◽  
Vol 113 (10) ◽  
pp. 949-951 ◽  
Author(s):  
W. H. Fogal ◽  
D. A. Winston ◽  
S. M. Lopushanski ◽  
D. A. MacLeod ◽  
A. J. Willcocks
Keyword(s):  
Seed Production ◽  
Picea Glauca ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
White Spruce ◽  
Cone Production ◽  
Seed Supply ◽  
Current Outbreak ◽  
Production Area ◽  
Production Areas

White spruce, Picea glauca (Moench) Voss, is a major commercial tree species used in reforestation programs throughout Canada, and seed requirements cannot be met in some years because of insect damage and the periodic nature of cone crops. The spruce budworm, Choristoneura fumiferana (Clem.), feeds on buds and cones of its hosts, causing a pronounced decrease in cone production (Schooley 1978). A current outbreak in northeastern Ontario poses a serious threat to white spruce seed supply from high value, managed seed production areas. Therefore, in 1979, we began an experiment to determine whether carbofuran, a systemic insecticide, could be used to protect buds and cones when applied to soil. We chose carbofuran because it has proved successful for control of some insects in seed orchards in the southeastern United States (DeBarr 1978)

scholarly journals Comparative Appraisal of Insecticidal Operations Against Spruce Budworm in Quebec During Two Outbreaks

1977 ◽  
Vol 53 (2) ◽  
pp. 71-76
Author(s):  
J. R. Blais
Keyword(s):  
Large Scale ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Single Treatment ◽  
Treatment Area ◽  
Residual Properties

Large-scale aerial applications of chemical insecticides against spruce budworm (Choristoneura fumiferana (clem.)) took place in Quebec during two outbreaks, 1952-58 (Outbreak I) and 1970-75 and continuing (Outbreak II), in an effort to prevent extensive mortality of fir and spruce. During Outbreak I yearly treatment consisted of one application of DDT at 0.6 kg/ha (8 oz./ac.); during Outbreak II it consisted of two applications of organophosphates and carbamates (mostly fenitrothion) for a total of 0.3 kg/ha (4 oz./ac.). The effects of a single treatment were evident for two years in Outbreak I because of residual properties of DDT, while in Outbreak II, effects were evident only in the year of application. Reduction in budworm populations due to treatment was considerably greater during Outbreak I than during Outbreak II. Average foliage protection in the year of treatment and in the following year was 38% and 60% respectively in Outbreak I, while it was 15% and 0% in Outbreak II. Spray operations in any one treatment area were repeated after an interval of three or four years due to population build up in Outbreak I; continuously high populations necessitated yearly applications of insecticides in Outbreak II. It is suggested that the current spraying policy in Quebec should be reappraised in the light of conditions that prevail.

Digestion of Spruce Budworm Larvae and Pupae in the Olive-backed Thrush, Hylochichla ustulata swainsoni (Tschudi)

1965 ◽  
Vol 97 (11) ◽  
pp. 1144-1149 ◽  
Author(s):  
L. J. Mook ◽  
H. G. W. Marshall
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Bird Predation ◽  
Digestion Rate ◽  
Insect Populations

AbstractTo use gizzard analysis quantitatively, in the assessment of bird predation on insect populations, information is needed on the time that identifiable remains of the prey can be found in the gizzard and on the rate at which these remains disappear. The digestion rate, measured by the disappearance of mandibles or cremasters, has been studied for larvae and pupae of the spruce budworm, Choristoneura fumiferana (Clem.), when eaten by the olive-backed thrush, Hylocichla ustulata swainsoni (Tschudi).

Spatiotemporal variability in tree and stand mortality caused by spruce budworm outbreaks in eastern Quebec

2010 ◽  
Vol 40 (1) ◽  
pp. 86-94 ◽  
Author(s):  
Mathieu Bouchard ◽  
David Pothier
Keyword(s):  
Large Scale ◽  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Spruce Budworm ◽  
Aerial Photographs ◽  
Spatiotemporal Variability ◽  
Tree Age ◽  
Mature Trees ◽  
Historical Trends ◽  
Understory Tree

We evaluated spruce budworm ( Choristoneura fumiferana (Clem.)) outbreak effects in nine study areas (60–86 ha each) located in the boreal forest of eastern Quebec (Canada). In each area, spruce budworm outbreak effects were measured from vegetation plots, dominant canopy and understory tree age structures, retrospective analysis of aerial photographs, defoliation records, and host tree growth reductions (dendrochronology). Large-scale synchronous outbreaks were detected across the region around the years 1880, 1915, 1950, and 1980. Overall, contrarily to what was expected for a region where host species (balsam fir ( Abies balsamea (L.) Mill.), Picea spp.) content is relatively high, these spruce budworm outbreaks seemed to have a relatively minor influence on stand dynamics, with the exception of the most recent outbreak (1980). This outbreak resulted in major stand mortality in the southern part of the region and favored the establishment of extensive tracts of young even-aged stands with few residual mature trees. This very abrupt increase in outbreak severity compared with earlier outbreaks, perhaps due to climatic or random factors, suggests that historical trends in successive outbreak severity should be extrapolated very cautiously and that the study of several outbreak cycles is needed to establish a range of natural variability that can be used to develop an ecosystem forest management strategy.

Spruce Budworm Parasite Investigations in the Lower St. Lawrence and Gaspé Regions of Quebec

1960 ◽  
Vol 92 (5) ◽  
pp. 384-396 ◽  
Author(s):  
J. R. Blais
Keyword(s):  
New Brunswick ◽  
Large Scale ◽  
Spruce Budworm ◽  
Weather Conditions ◽  
Balsam Fir ◽  
Population Fluctuations ◽  
Factors Associated ◽  
Outbreak Area ◽  
Biological Studies ◽  
Unfavourable Weather

A spruce budworm outbreak started in Quebec and adjoining parts of New Brunswick in 1949 and spread each year until by 1955 most balsam fir stands within an area of 32,000 square miles were attacked. Approximately 45 per cent of this area was in the Lower St. Lawrence and Gaspe regions of Quebec. In Quebec, important population reductions took place in various sectors of the outbreak area as a result of unfavourable weather conditions in 1956 and 1957 (Blais, 1958a, 1958b), and the final collapse occurred in 1958 when populations returned to the endemic level throughout the area (Blais and Martineau, 1958). In New Brunswick, a relatively small outbreak area remained at the end of the summer in 1958 (Webb et al., 1959). The large-scale aerial applications of DDT begun in New Brunswick in 1952, and in Quebec in 1954, were continued until 1958. Biological studies in connection with the spraying were carried out in both provinces. In Quebec these studies consisted of assessing spruce budworm population fluctuations in both sprayed and unsprayed areas and in determining, where possible, the causes for these fluctuations. All factors associated with changes in population could not be adequately measured over such a large territory, but a real attempt was made to obtain information on parasitism. The present paper deals with this aspect of the studies.

Périodicité et synchronisme des épidémies de la tordeuse des bourgeons de l'épinette au Québec

2003 ◽  
Vol 33 (10) ◽  
pp. 1947-1961 ◽  
Author(s):  
Yves Jardon ◽  
Hubert Morin ◽  
Pierre Dutilleul
Keyword(s):  
Population Dynamics ◽  
Choristoneura Fumiferana ◽  
Local Population ◽  
Spruce Budworm ◽  
Periodic Component ◽  
Moran Effect ◽  
Regional Effect ◽  
Migration Effect ◽  
Different Types ◽  
Insect Populations

A time series analysis was performed on 32 dendrochronological chronologies using Dutilleul's multi frequential periodo gram. Our aim was to estimate the periodicities of spruce budworm (Choristoneura fumiferana (Clem.)) outbreaks in the province of Quebec. Our analysis estimated a signal of 25-38 years corresponding to spruce budworm outbreaks. Analyses conducted in the 20th century indicated the existence of true periodicities in half of the series suggesting local population dynamics. These periodicities were estimated to be 29-34 years. For the other series, outbreaks were explained by the addition of a second periodic component to the fundamental periodicity. These combined periodicities (pseudoperiodicities or complex periodicities) described most of the 130-year series analysed. The lack of several outbreaks explained part of the combined periodicity. The results suggest a migration effect and complex local population dynamics. A third periodic component explains the double epidemic waves. These estimated periodicities are often similar and in phase. We believe that a common regional effect (the Moran effect) acts on the minor fluctuations of the insect populations and helps synchronize the outbreaks. This research shows that different types of outbreak dynamics can be found within a same insect species.

C. P. Alexander review

2012 ◽  
Vol 144 (3) ◽  
pp. 379-395 ◽  
Author(s):  
Marc Rhainds ◽  
Edward G. Kettela ◽  
Peter J. Silk
Keyword(s):  
Population Density ◽  
Mating Success ◽  
Large Scale ◽  
Mating Disruption ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Field Studies ◽  
Management Tool ◽  
Consistent Difference ◽  
Gravid Females

AbstractThe Canadian registration in 2007 of Disrupt SBW Micro-Flakes®, a pheromone-based product for control of spruce budworm,Choristoneura fumiferana(Clemens), paved the way for large-scale trials to test the practicality of mating disruption as a commercial pest management strategy. We review results from field and laboratory experiments on pheromone-based mating disruption of spruce budworm conducted from 1974 to 2008. Application of pheromone from the ground or the air consistently reduced the orientation of males toward pheromone sources. Mating disruption also reduced the mating success of caged or tethered females in 15 of 16 field studies where this parameter was recorded, but had only a limited effect on the mating success of feral females. No consistent difference in the density of egg masses in control and treated plots was observed, which has often been attributed to immigration of gravid females into pheromone-treated plots. Laboratory studies suggest that false-trail following is the predominant mechanism underlying mating disruption in spruce budworm. The enhanced mating success of females with increasing population density suggests that mating disruption should target low-density emergent populations during the initial phase of an outbreak. Constraints that may limit the potential of mating disruption as a management tool include (1) difficulties associated with obtaining accurate sampling estimates at low population density to forecast the onset of outbreaks, (2) potential behavioral adaptations by which females enhance their mating success when the atmosphere is treated with pheromone, and (3) long-range dispersal of females by flight.

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