Ecological Entomology (2008) 33, 362-373

Jacques Régnière and Vince G. Nealis (2008)
The fine-scale population dynamics of spruce budworm: survival of early instars related to forest condition
Ecological Entomology 33 (3), 362-373
Abstract: 1. A lagged, density-dependent relationship between survival of early instars and host-tree condition is revealed during outbreaks of spruce budworm, Choristoneura fumiferana Clem. Persistent damage to hosts leads to deterioration of the stand.
2. Resource limitation affects survival during early-instar dispersal of spruce budworm. Impediments to distinguishing these events with estimates of survival were overcome with a simple model that describes the dispersal and survival processes. The model was used to analyse a recent 15-year population series from Black Sturgeon Lake and two historical datasets from Green River, in Canada.
3. Defoliation-induced damage to the trees resulted in increased losses of spring-emerging larvae that are dispersing in search of feeding sites. Losses were further exacerbated by biotic factors such as maternal fecundity, rates of infection by the pathogen, Nosema fumiferanae, and by weather-related effects on the foraging period.
4. Survival of early-stage budworm larvae in persistent outbreaks declined and the likelihood of other density-related factors such as rate of mortality from natural enemies increased. These results may reconcile outstanding differences in interpretation of the role of the forest resource in spruce budworm population dynamics and point to a common process linking the dynamics of other well-known budworm species.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Jacques Regniere

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
population dynamics/epizootiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Choristoneura fumiferana		Canada (east)
Nosema fumiferanae (entomopathogen)	Choristoneura fumiferana		Canada (east)