Responses of leaf-eating insects feeding on aspen to emissions from the Middle Ural copper smelter.

Foliar damage to aspen from leaf-chewing insects and miners has been assessed during a 4-year period in the environs of a large copper smelter in the Middle Urals. It has been shown that the total area removed, proportion of damaged leaves, and average area removed per damaged leaf are considerably smaller near the smelter than in the background zone. The degree of the effect is similar for all three parameters and remains stable with time. Both groups of leaf pests display lower trophic activity in the impact zone, but the effect of pollution on leaf-chewing insects is greater than on miners, while individual features of the tree and its environment affect miners more strongly than leaf-chewing insects. [ABSTRACT FROM AUTHOR]