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Wood losses and economical threshold of Btk aerial spray operation against spruce budworm
Author(s) -
Fournier Cédric,
Bauce Éric,
Dupont Alain,
Berthiaume Richard
Publication year - 2010
Publication title -
pest management science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.296
H-Index - 125
eISSN - 1526-4998
pISSN - 1526-498X
DOI - 10.1002/ps.1878
Subject(s) - spruce budworm , balsam , abies balsamea , choristoneura fumiferana , aerial application , biopesticide , bacillus thuringiensis , bruton's tyrosine kinase , biology , toxicology , horticulture , forestry , botany , agronomy , tortricidae , pest analysis , pesticide , geography , signal transduction , biochemistry , genetics , tyrosine kinase , bacteria
BACKGROUND: Spruce budworm, Choristoneura fumiferana (Clem.), causes cumulative defoliation and hence annual growth loss of the balsam fir, Abies balsamea (L.) Mill, host tree. Annual growth increments of mixed balsam fir stands were measured by stem analysis over a 9 year period (1994–2002), when Bacillus thuringiensis ssp. kurstaki ( Btk ) was applied to control spruce budworm defoliation. With this approach, it was possible to quantify the change in stand volume growth after aerial spray applications of Btk . RESULTS: Differences between the periodic volume increment of protected and unprotected plots were statistically significant, while differences between protected and budworm‐free plots were not significant. After 9 years, the difference in periodic increment between protected and unprotected plots was 20 m 3 ha −1 , and the difference in periodic mortality was 20.5 m 3 ha −1 . CONCLUSION: An economic assessment of Btk treatments indicates that biopesticide aerial spraying operations are justified, as they prevented substantial balsam fir mortality and growth losses over the 9 year study. Copyright © 2009 Society of Chemical Industry