A Conceptual Framework for the Spruce Budworm Early Intervention Strategy: Can Outbreaks be Stopped?

Johns, Rob C.; Bowden, Joseph J.; Carleton, Drew; Cooke, Barry J.; Edwards, Sara; Emilson, Erik J. S.; James, Patrick M. A.; Kneeshaw, Daniel; MacLean, David A.; Martel, Véronique; Moise, Eric R.D.; Mott, Gordon D.; Norfolk, Chris J.; Owens, Emily; Pureswaran, Deepa S.; Quiring, Dan T.; Régnière, Jacques; Richard, B Pollnac; Stastny, Michael

doi:10.3390/f10100910

Cited by 49 publications

(51 citation statements)

References 83 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Taken together, these results indicate that insecticide applications, when efficacious, can reduce populations that happen to increase above the unstable eruption threshold. This is the essence of what is termed an "early intervention" strategy, where treatment in one year may have benefits lasting well beyond the treatment year [5].…”

Section: Resultsmentioning

confidence: 99%

“…It is interesting that mortality attributable to insecticides was higher in lower density populations both in 2013 and in 2014, despite the fact that two products with very different modes of action were used. This could very well be an indication of compensation (see [5]): Some of the mortality due to competition was relaxed by the insecticide applications.…”

Section: Population Density and Survivalmentioning

confidence: 99%

“…There are two distinct views on how spruce budworm outbreaks start, and what controls their pattern of termination and recurrence (Figure 1; for a good description of these two contrasting theories, see Table SI1 in [5]). One theory dates back to the 1960 s and was formalized in the 1970 s as "Double-equilibrium theory" [6].…”

Section: Introductionmentioning

confidence: 99%

“…Parameter estimates of Equation(5) describing the relationship between egg and surviving adult density in the 5 datasets available in this study. R 2 = 0.92.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Dynamics and Management of Rising Outbreak Spruce Budworm Populations

Régnière

Cooke

Béchard

et al. 2019

Forests

Self Cite

View full text Add to dashboard Cite

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 (L 4 ). 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.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Population Density and Survivalmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

“…Parameter estimates of Equation(5) describing the relationship between egg and surviving adult density in the 5 datasets available in this study. R 2 = 0.92.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Dynamics and Management of Rising Outbreak Spruce Budworm Populations

Régnière

Cooke

Béchard

et al. 2019

Forests

Self Cite

View full text Add to dashboard Cite

show abstract

“…Over the last five years, a $30 million research project has tested another possible management tactic, termed an early intervention strategy, aimed at area-wide management of spruce budworm populations [28]. This includes intensive monitoring to detect 'hotspots' of rising budworm populations before defoliation occurs, targeted insecticide treatment to prevent spread, and detailed research into effects on target and non-target insects [28,29].…”

Section: Introductionmentioning

confidence: 99%

Protection Strategy against Spruce Budworm

MacLean

2019

Forests

Self Cite

View full text Add to dashboard Cite

Spruce budworm is one of the most significant forest insects worldwide, in terms of outbreak extent, severity, and economic impacts. As a defoliator, spruce budworm larvae are susceptible to insecticide protection, and improvements in efficacy and reductions in non-target environmental effects have made such protection attractive. In this Special Issue, 12 papers describe the advances in spruce budworm protection, most notably an 'early intervention strategy' approach that after six years of trials in New Brunswick, Canada, shows considerable success to date in reducing budworm outbreak occurrence and severity.

show abstract

Improving coral cover using an integrated pest management framework

Rogers,

Plagányi,

Babcock

et al. 2023

Ecological Applications

View full text Add to dashboard Cite

Integrated pest management (IPM) leverages our understanding of ecological interactions to mitigate the impact of pest species on economically and/or ecologically important assets. It has primarily been applied in terrestrial settings (e.g. agriculture), but rarely been attempted for marine ecosystems. The crown‐of‐thorns starfish (CoTS), Acanthaster spp., is a voracious coral predator throughout the Indo‐Pacific where it undergoes large population increases (irruptions), termed outbreaks. During outbreaks CoTS act as a pest species and can result in substantial coral loss. Contemporary management of CoTS on the Great Barrier Reef (GBR) adopts facets of the IPM paradigm to manage these outbreaks through strategic use of direct manual control (culling) of individuals in response to ecologically based target thresholds. There has, however, been limited quantitative analysis of how to optimise the implementation of such thresholds. Here we use a multispecies modelling approach to assess the performance of alternative CoTS management scenarios for improving coral cover trajectories. Scenarios examined varied in terms of their ecological threshold target, the sensitivity of the threshold, and level of management resourcing. Our approach illustrates how to quantify multidimensional trade‐offs in resourcing constraints, concurrent CoTS and coral population dynamics, stringency of target thresholds, and the geographical scale of management outcomes (number of sites). We found strategies with low target density thresholds for CoTS (≤0.03 CoTS.min‐1) could act as “Effort Sinks” and limit the number of sites that could be effectively controlled, particularly under CoTS population outbreaks. This was because a handful of sites took longer to control which meant other sites were not controlled. Higher density thresholds (e.g. 0.04‐0.08 CoTS.min‐1), tuned to levels of coral cover, diluted resources amongst sites but were more robust to resourcing constraints and pest population dynamics. Our study highlights trade‐off decisions when using an IPM framework and is informing implementation of threshold‐based strategies on the GBR.

show abstract

A Conceptual Framework for the Spruce Budworm Early Intervention Strategy: Can Outbreaks be Stopped?

Cited by 49 publications

References 83 publications

Dynamics and Management of Rising Outbreak Spruce Budworm Populations

Dynamics and Management of Rising Outbreak Spruce Budworm Populations

Protection Strategy against Spruce Budworm

Improving coral cover using an integrated pest management framework

Contact Info

Product

Resources

About