Host Tree Species Affects Spruce Budworm Winter Survival
Host Tree Species Affects Spruce Budworm Winter Survival
复制标题
寄主树种影响云杉芽虫冬季生存
作者：
R. Berthiaume;C. Hébert;Martin Charest;A. Dupont;É. Bauce
摘要 随着当前全球变暖的趋势，有人认为云杉芽虫的爆发可能会蔓延到北方森林的北部地区。然而，向北扩张的主要制约因素是合适的寄主树的可用性和昆虫的冬季生存能力。本研究旨在确定幼虫取食香脂冷杉、白云杉和黑云杉对云杉芽虫亲本和后代的各种生活史性状的影响。结果表明，越冬幼虫后代的重量及其冬季存活率受到亲代幼虫取食的寄主树种的影响。白云杉是云杉芽虫最合适的寄主，产生最重的蛹和最重的越冬幼虫，而黑云杉最不适合，产生最小的蛹和最小的越冬后代。以黑云杉为食的亲本产生的越冬幼虫也比以香脂冷杉或白云杉为食的亲本产生的个体遭受更高的冬季死亡率。随着全球变暖的当前趋势，云杉芽虫预计将其范围扩大到以黑云杉为主要树种的北部北方森林。如果黑云杉的后代冬季存活率持续较低，这种北部范围的扩张可能不会导致疫情爆发。
Abstract 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.