Berthiaume Richard, Hébert Christian, Charest Martin, Dupont Alain, Bauce Éric
Faculté de foresterie, de géographie et de géomatique, Département des sciences du bois et de la forêt, Université Laval, Pavillon Abitibi-Price, 2405 rue de la Terrasse, Québec, Québec, Canada.
Ressources Naturelles Canada, Service canadien des forêts, Centre de foresterie des Laurentides, Québec, Québec, G1V 4C7 Canada.
Environ Entomol. 2020 Apr 14;49(2):496-501. doi: 10.1093/ee/nvaa020.
With current trends in global warming, it has been suggested that spruce budworm outbreaks may spread to northern parts of the boreal forest. However, the major constraints for a northward expansion are the availability of suitable host trees and the insect winter survival capacity. This study aimed to determine the effect of larval feeding on balsam fir, white spruce and black spruce on various spruce budworm life history traits of both the parental and the progeny generations. Results indicated that the weight of the overwintering larval progeny and their winter survival were influenced by host tree species on which larvae of the parental generation fed. White spruce was the most suitable host for the spruce budworm, producing the heaviest pupae and the heaviest overwintering larvae while black spruce was the least suitable, producing the smallest pupae and the smallest overwintering progeny. Overwintering larvae produced by parents that fed on black spruce also suffered higher winter mortality than individuals coming from parents that fed on balsam fir or white spruce. With current trends in global warming, spruce budworm is expected to expand its range to northern boreal forests where black spruce is the dominant tree species. Such northern range expansion might not result in outbreaks if low offspring winter survival on black spruce persist.
随着全球变暖的当前趋势，有人提出云杉芽虫的爆发可能会蔓延到北方针叶林的北部地区。然而，向北扩张的主要限制因素是合适寄主树的可用性以及昆虫的冬季生存能力。本研究旨在确定亲代和子代两代云杉芽虫在以香脂冷杉、白云杉和黑云杉为食时，幼虫取食对其各种生活史特征的影响。结果表明，越冬幼虫后代的体重及其冬季存活率受亲代幼虫取食的寄主树种影响。白云杉是云杉芽虫最适宜的寄主，能产出最重的蛹和最重的越冬幼虫，而黑云杉是最不适宜的寄主，产出的蛹最小，越冬后代也最小。取食黑云杉的亲代所产的越冬幼虫，其冬季死亡率也高于取食香脂冷杉或白云杉的亲代所产的个体。随着全球变暖的当前趋势，预计云杉芽虫的分布范围将扩展到以黑云杉为优势树种的北方针叶林。如果黑云杉上后代冬季存活率持续较低，这种向北的分布范围扩展可能不会导致爆发。
