Canadian Forest Service Publications

Epidemiology of the spruce budworm in western Ontario: a discussion. 1985. Blais, J.R. The Forestry Chronicle 61: 494-498.

Year: 1985

Available from: Laurentian Forestry Centre

Catalog ID: 14357

Language: English

CFS Availability: Order paper copy (free), PDF (request by e-mail)


Spruce budworm outbreaks for the past two centuries in western Ontario occurred in two main sectors, the Lake Nipigon and the Lac Seul sectors. Some were common to both sectors, while others were specific to one or the other. Intervals between infestations within sectors averaged about 60 years. For western Ontario, budworm populations oscillated at irregular intervals ranging from 15 to 60 years. Infestations generally originated in the boreal forest in centers with high concentrations of fir, and then appeared in areas with lower volumes of fir. Fir content and the susceptibility to budworm attack of forests in western Ontario are compared with conditions prevailing in Quebec and the Maritimes. There are new outbreaks in western Ontario, and their future behavior could clarify some aspects of budworm epidemiology.



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