Hemming Jocelyn D C, Lindroth Richard L
237 Russell Labs, Environmental Toxicology Center, 1630 Linden Drive, 53706, Madison, WI, USA.
237 Russell Labs, Department of Entomology, 1630 Linden Drive, Madison, 53706, WI, USA.
Oecologia. 1995 Jul;103(1):79-88. doi: 10.1007/BF00328428.
Individual quaking aspen trees vary greatly in foliar chemistry and susceptibility to defoliation by gypsy moths and forest tent caterpillars. To relate performance of these insects to differences in foliar chemistry, we reared larvac from egg hatch to pupation on leaves from different aspen trees and analyzed leaf samples for water, nitrogen, total nonstructural carbohydrates, phenolic glycosides, and condensed tannins. Larval performance varied markedly among trees. Pupal weights of both species were strongly and inversely related to phenolic glycoside concentrations. In addition, gypsy moth performance was positively related to condensed tannin concentrations, whereas forest tent caterpillar pupal weights were positively associated with leaf nitrogen concentrations. A subsequent study with larvae fed aspen leaves supplemented with the phenolic glycoside tremulacin confirmed that the compound reduces larval performance. Larvae exhibited increased stadium durations and decreased relative growth rates and food conversion efficiencies as dietary levels of tremulacin increased. Differences in performance were more pronounced for gypsy moths than for forest tent caterpillars. These results suggest that intraspecific variation in defensive chemistry may strongly mediate interactions between aspen, gypsy moths and forest tent caterpillars in the Great Lakes region, and may account for differential defoliation of aspen by these two insect species.
个体颤杨在叶片化学组成以及对舞毒蛾和森林天幕毛虫落叶危害的易感性方面差异极大。为了将这些昆虫的生长情况与叶片化学组成的差异联系起来，我们将幼虫从孵化饲养至化蛹，所用叶片来自不同的杨树，并分析叶片样本中的水分、氮、总非结构性碳水化合物、酚类糖苷和缩合单宁。幼虫的生长情况在不同树木间差异显著。两种昆虫的蛹重均与酚类糖苷浓度呈强烈负相关。此外，舞毒蛾的生长情况与缩合单宁浓度呈正相关，而森林天幕毛虫的蛹重与叶片氮浓度呈正相关。随后一项对喂食添加了酚类糖苷震颤素的杨树叶的幼虫进行的研究证实，该化合物会降低幼虫的生长情况。随着饮食中震颤素水平的增加，幼虫的龄期持续时间延长，相对生长率和食物转化效率降低。舞毒蛾的生长差异比森林天幕毛虫更为明显。这些结果表明，防御性化学物质的种内变异可能强烈调节五大湖地区杨树、舞毒蛾和森林天幕毛虫之间的相互作用，并可能解释这两种昆虫对杨树落叶危害的差异。
