Journal of Pest Science (2015) 88, 593-603
Alvaro Fuentealba, Éric Bauce and Alain Dupont (2015)
Bacillus thuringiensis efficacy in reducing spruce budworm damage as affected by host tree species
Journal of Pest Science 88 (3), 593-603
Abstract: Efficacy of commercial formulations of Bacillus thuringiensis ssp. kurstaki (Btk) against spruce budworm Choristoneura fumiferana in black spruce (Picea mariana (Mill.) BSP), white spruce (P. glauca (Moench) Voss) and balsam fir (Abies balsamea (L.) Mill.) was investigated in Québec's Côte-Nord region. As expected, larval mortality was higher in Btk-treated plots (80.26 ± 2.34 %) than in control plots (66.32 ± 2.80 %). There were no differences in larval mortality among the three host tree species tested. Btk was most efficient in reducing spruce budworm defoliation when applied to black spruce and white spruce trees. Black spruce and white spruce exhibited lower final defoliation in Btk-treated plots than balsam fir. Btk applications produced a reduction in defoliation of 36 % in balsam fir, 44 % in white spruce and 41 % in black spruce. Control plots exhibited about 35 % higher amount of current-year foliage destroyed (AFD) and 56 % lower amount of current-year foliage remaining (ARF) than Btk-treated plots, whereas no differences in the amount of current-year foliage produced (AFP) were observed among host tree species. Black spruce trees showed the lowest AFD. Although not statistically significant, black spruce also showed the highest ARF. Our results suggest that Btk application is more efficient in protecting against spruce budworm damage when it is applied to spruce species than it is to balsam fir. It appears that the observed inter-specific differences in host tree foliage protection might be related to interactions between Btk, host tree foliage, and larval feeding behaviour.
(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): Alvaro Fuentealba, Eric Bauce
Research topic(s) for pests/diseases/weeds:
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
environment/habitat manipulation
