scholarly journals Dynamics and Management of Rising Outbreak Spruce Budworm Populations

Forests ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 748 ◽  
Author(s):  
Jacques Régnière ◽  
Barry Cooke ◽  
Ariane Béchard ◽  
Alain Dupont ◽  
Pierre Therrien
Keyword(s):  
Population Growth ◽  
Density Dependence ◽  
Natural Enemies ◽  
Choristoneura Fumiferana ◽  
Regional Scale ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Migration Activity ◽  
Larval Stages ◽  
The Impact

Management of spruce budworm, Choristoneura fumiferana (Clem.), outbreak spread requires understanding the demographic processes occurring in low, but rising populations. For the first time, detailed observations were made in the early stages of outbreak development. We sampled populations over a three-year period in both treated and untreated populations in the Lower St-Lawrence region of Quebec, Canada, and measured the density-dependence of survival and population growth rates, and the impact of natural enemies and insecticides. Insecticides tested were Bacillus thuringiensis (Berliner 1915) and tebufenozide. We recorded strong density-dependence of survival between early larval stages and adult emergence, explained largely by the variation of natural enemy impacts and overcrowding. We also observed inverse density-dependence of apparent fecundity: net immigration into lower-density populations and net emigration from the higher, linked to a threshold of ~25% defoliation. Because of high migration rates, none of the 2013 treatments reduced egg populations at the end of summer. However lower migration activity in 2014 allowed population growth to be reduced in treated plots. This evidence lends support to the conclusion that, for a budworm population to increase to outbreak density, it must be elevated via external perturbations, such as immigration, above a threshold density of ~4 larvae per branch tip (L4). Once a population has increased beyond this threshold, it can continue growing and itself become a source of further spread by moth migration. These findings imply that populations can be brought down by insecticide applications to a density where mortality from natural enemies can keep the reduced population in check, barring subsequent immigration. While we recognize that other factors may occasionally cause a population to exceed the Allee threshold and reach outbreak level, the preponderance of immigration implies that if all potential sources of significant numbers of moths are reduced on a regional scale by insecticide applications, a widespread outbreak can be prevented, stopped or slowed down by reducing the supply of migrating moths.

EXPOSING LARVAE OF THE SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE) TO SUBLETHAL DOSES OF BACILLUS THURINGIENSIS SUBSP. KURSTAKI DOES NOT AFFECT SURVIVAL DURING THE PUPAL STAGE

2000 ◽  
Vol 132 (3) ◽  
pp. 341-343 ◽  
Author(s):  
Kees van Frankenhuyzen ◽  
John Dedes
Keyword(s):  
Bacillus Thuringiensis ◽  
Choristoneura Fumiferana ◽  
Pupal Stage ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Larval Population ◽  
Immature Development ◽  
Sublethal Doses ◽  
Carry Over ◽  
The Impact

A process-oriented model was recently developed to simulate the efficacy of spray products containing Bacillus thuringiensis Berliner subsp. kurstaki (Bacillaceae) against the spruce budworm, Choristoneura fumiferana Clemens (Cooke and Régnière 1996). The model accurately predicted foliage protection and larval population reduction during validation spray trials (Régnière and Cooke 1998; Cooke and Régnière 1999). The impact of treatment on budworm generation survival was generally well mimicked by the model except for a consistent overestimation of survival at the end of immature development in the treated plots. Régnière and Cooke (1998) speculated that residual mortality due to treatment may be occurring during the pupal stage. Carry-over of B. thuringiensis from larvae to pupae has been documented for spruce budworm (Klein and Lewis 1966) and several other Lepidoptera (Legner and Oatman 1962; Angus 1965). Although we recently investigated the response of spruce budworm larvae to ingestion of sublethal doses of B. thuringiensis (Pedersen et al. 1997), effects on pupal survival or adult emergence were not examined. In this note, we report the results of an experiment designed to assess such effects.

FACTORS AFFECTING ADULT EMERGENCE AND MATING BEHAVIOR OF THE EASTERN SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1975 ◽  
Vol 107 (9) ◽  
pp. 967-977 ◽  
Author(s):  
C. J. Sanders
Keyword(s):  
Field Experiments ◽  
Choristoneura Fumiferana ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Field Conditions ◽  
Continuous Illumination ◽  
Degree Days ◽  
Factors Affecting ◽  
Eastern Spruce Budworm ◽  
Duration Of Copulation

AbstractLaboratory and field experiments indicate that the female spruce budworm (Choristoneura fumiferana (Clem.)) pupal stadium requires approximately 122C degree-days above a threshold of 7.2 °C (45°F), the male 124. Emergence time on any given day depends on temperature but is independent of photoperiod. Under field conditions male and female budworm mate only once per 24-h period. In the laboratory under continuous illumination females mate repeatedly and males readily mate a second time within a few hours, but the duration of the second copulation is abnormally long. The probability of multiple matings under field conditions is reduced by the restricted period of sexual activity coupled with the duration of copulation and the lower competitiveness of mated insects. Antennae are essential to the male for successful copulation.

A METHOD FOR REARING THE LARVAL STAGES OF THE EASTERN SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA CLEMENS (LEPIDOPTERA: TORTRICIDAE), FOR PHYSIOLOGICAL STUDIES

1990 ◽  
Vol 122 (6) ◽  
pp. 1271-1272 ◽  
Author(s):  
Hemendra Mulye ◽  
Roger Gordon
Keyword(s):  
Population Dynamics ◽  
North America ◽  
Choristoneura Fumiferana ◽  
Insect Pest ◽  
Spruce Budworm ◽  
Forest Pest ◽  
Forest Insect ◽  
Larval Stages ◽  
Eastern Spruce Budworm ◽  
Physiological Studies

The eastern spruce budworm, Choristoneura fumiferana Clemens, is the most widely distributed and destructive forest insect pest in North America. Although much is known about the ecology, population dynamics, and impact of C. fumiferana on tree growth (Sanders et al. 1985), there is very little information available on the physiology of this forest pest. Physiological studies are crucial to the development of novel strategies for spruce budworm control.

The Interaction of the Spruce Budworm, Choristoneura fumiferana (Clem.), and the Parasite Glypta fumiferanae (Vier.)

1960 ◽  
Vol 92 (11) ◽  
pp. 839-850 ◽  
Author(s):  
C. A. Miller
Keyword(s):  
New Brunswick ◽  
Choristoneura Fumiferana ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Actual Number ◽  
Emergence Period ◽  
Realistic Estimate ◽  
Host Generation

This is the second of a series of papers (Miller, 1959) describing the interaction of primary parasites and the spruce budworm, Choristoneura fumiferana (Clem.), based on data collected during an outbreak of the budworm in northern New Brunswick during the period 1947–1958. The first paper showed that the interaction between the spruce budworm and Apanteles fumiferanae Vier. is adequately described by the general mathematicai model developed by Watt (1959). The data on the parasite Glypta fumiferanae (Vier.) to be presented in this paper are also analysed by means of Watt's model and consequently the method is essentially the same. There is, however, one important difference. In the case of A. fumiferanae, the estimated number of adult parasites was only an index based on the potential number emerging from the previous host generation. The observed density of G. fumiferanae is a more realistic estimate. It is based on the actual number of cocoons found on the foliage during the adult emergence period.

SEASONAL BIOLOGY OF METEORUS TRACHYNOTUS VIER. (HYMENOPTERA: BRACONIDAE) AND OF ITS OVERWINTERING HOST CHORISTONEURA ROSACEANA (HARR.) (LEPIDOPTERA: TORTRICIDAE)

1989 ◽  
Vol 121 (9) ◽  
pp. 745-756 ◽  
Author(s):  
J. Maltais ◽  
J. Régnière ◽  
C. Cloutier ◽  
C. Hébert ◽  
D.F. Perry
Keyword(s):  
Sex Ratio ◽  
Choristoneura Fumiferana ◽  
Light Trap ◽  
Adult Emergence ◽  
Deciduous Trees ◽  
Choristoneura Rosaceana ◽  
Deciduous Species ◽  
Percentage Parasitism ◽  
Larval Stages ◽  
Obliquebanded Leafroller

AbstractThe braconid parasitoid Meteorus trachynotus Vier. was found in overwintered larvae of the obliquebanded leafroller, Choristoneura rosaceana (Harr.), on foliage of a variety of deciduous species, well before the parasitoid’s attack on the spruce budworm, Choristoneura fumiferana (Clem.). In the spring, percentage parasitism of C. rosaceana by M. trachynotus was 8.0 and 18.8% in 1986 and 1987, respectively. Maximum parasitism on C. fumiferana (35 and 4% in 1986 and 1987, respectively) was reached in late June, at a time when over 50% of M. trachynotus cocoons found on deciduous vegetation had emerged. Twenty days later, parasitoids produced on C. fumiferana reached 50% adult emergence. The catches of adult parasitoids on sticky traps placed on deciduous trees and on conifers showed two periods of adult activity. Based on the sex ratio of captured parasitoids, male M. trachynotus were active at emergence sites, whereas females were found mostly in the habitats of available hosts. The phenology of C. rosaceana was observed in 1987. As indicated by light-trap captures, males fly sooner than females. Eggs were laid in July, and so the early larval stages were available to female M. trachynotus as overwintering hosts. Several parasitoids common to C. rosaceana and C. fumiferana were identified.

THE MATING STATUS OF FIELD-COLLECTED MALE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (CLEM.) (LEPIDOPTERA: TORTRICIDAE), IN RELATION TO TRAP LOCATION, SAMPLING METHOD, SAMPLING DATE, AND ADULT EMERGENCE

1988 ◽  
Vol 120 (8-9) ◽  
pp. 821-830 ◽  
Author(s):  
J.C. Bergh ◽  
E.S. Eveleigh ◽  
W.D. Seabrook
Keyword(s):  
Sampling Method ◽  
Choristoneura Fumiferana ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Mate Location ◽  
Mating Status ◽  
Baited Traps ◽  
Trap Location ◽  
Flight Season

AbstractMale spruce budworm moths, Choristoneura fumiferana (Clem.), were captured in 1986 and 1987 and the proportion recently mated was determined for each sample. Mating status was examined in relation to trap location, sampling method, sampling date, and adult emergence. On a given day the proportion of recently mated males captured was similar among pheromone-baited traps both within and among test sites. The number of males trapped increased with increasing trap elevation, although there was no difference in the proportion of mated males at each elevation. Males exhibiting “mate-location behaviour” were captured individually with an insect net and were found to be mated in the same proportion as those caught in pheromone-baited traps. The proportion of recently mated males trapped tended to increase during the early part of the flight season, to fluctuate during the middle portion, and then to decline toward the end of the season. This pattern was due, in part, to adult emergence trends.

scholarly journals A Foliar Endophyte of White Spruce Reduces Survival of the Eastern Spruce Budworm and Tree Defoliation

Forests ◽  
2020 ◽  
Vol 11 (6) ◽  
pp. 659 ◽  
Author(s):  
Dan Quiring ◽  
Greg Adams ◽  
Andrew McCartney ◽  
Sara Edwards ◽  
J. David Miller
Keyword(s):  
Endophytic Fungus ◽  
Picea Glauca ◽  
Integrated Management ◽  
Choristoneura Fumiferana ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
White Spruce ◽  
Tree Defoliation ◽  
Eastern Spruce Budworm

Wild eastern spruce budworm (Choristoneura fumiferana Clemens) were reared on white spruce (Picea glauca (Moench) Voss) trees, half of which had been previously inoculated with a native endophytic fungus, Phialocephala scopiformis DAOM 229536 Kowalski and Kehr (Helotiales, Ascomycota). Survival up to pupation and up to adult emergence was approximately 27% higher for budworm juveniles that developed on control trees compared to trees inoculated with the endophyte. The endophyte did not influence the size or sex of survivors but did reduce defoliation by approximately 30%. Reductions in defoliation on endophyte-inoculated versus control trees, due to reductions in survival of juvenile budworms, suggests that tree inoculations with P. scopiformis could play an important role in integrated management programs against the eastern spruce budworm.

scholarly journals Modeling Climatic Influences on Three Parasitoids of Low-Density Spruce Budworm Populations. Part 2: Meteorus trachynotus (Hymenoptera: Braconidae)

Forests ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 155
Author(s):  
Jacques Régnière ◽  
Rémi Saint-Amant ◽  
Jean-Claude Thireau ◽  
Pierre Therrien ◽  
Christian Hébert ◽  
...  
Keyword(s):  
Choristoneura Fumiferana ◽  
Seasonal Pattern ◽  
Spruce Budworm ◽  
Seasonal Development ◽  
Choristoneura Rosaceana ◽  
Field Observations ◽  
Seasonal Interactions ◽  
Northern Portion ◽  
Response To Temperature ◽  
The Impact

This is the second article of a series of three where we develop temperature-driven models to describe the seasonal interactions between parasitoids and their hosts which we use to explore the impact of climate on their spatiotemporal biology. Here, we model the biology of Meteorus trachynotus (Hymenoptera: Braconidae) with an individual-based model of its daily interactions with two host species. This model predicts the performance of the parasitoid in response to temperature affecting its seasonal development and that of the two hosts. We compare model output with an extensive set of field observations from natural host populations. The predicted activity of the first adult parasitoid generation closely matches the seasonal pattern of attack on the spruce budworm, Choristoneura fumiferana (Lepidoptera: Tortricidae) within the limitations of available data. The model predicts 1–4 full generations of M. trachynotus per year in eastern North America, with generations well synchronized with larvae of a known overwintering host, the obliquebanded leafroller Choristoneura rosaceana. The model predicts the observed density dependence of parasitism on spruce budworm. Predicted performance exhibits spatial variation caused by complex life-history interactions, especially synchrony with the overwintering host. This leads to a better performance in warm but not hot environments at middle latitudes and elevations. The model’s predicted spatial patterns correspond closely to our field observations on the frequency of parasitism on spruce budworm. Under climate change, the model predicts that the performance of M. trachynotus populations will improve in the northern portion of its range.

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