Affect of trembling aspen (Populus tremuloides) diversity on the abundance and fate of aspen blotch miners (Lithocolletis salicifoliella) Cham. (Lepidoptera: Gracillariidae).

Abstract

The purpose of this experiment is to increase current knowledge of the relationship between Lithocolettis salicifoliella and Populus tremuloides, specifically focusing on diversity of aspen stands and how this affects the abundance, fate and cause of death of the blotch miners. We selected two stands of aspen trees, a monoculture and a polyculture, that were equidistant from a red pine plantation. We counted the numbers of trees and trembling aspens, and gathered leaves to observe the blotch miners in the lab. We determined the fate and cause of death of each miner that we gathered, and the average area of the leaves within each stand. We found significant difference for cause of death between the two stands and the abundace of blotch miners between the two stands. Trembling aspen within a monoculture have a greater chance of being infested by miners than those in a polyculture because of the protection that the polyculture provides. The monoculture had a greater chance of being infested by parasites and less of a chance of being preyed upon than the polyculture. Parasitism is higher in plants with chemical and physical alterations, and the monoculture has less protection from damage due to less vegetation. Predation may be higher in the polyculture because plant predators live in the surrounding vegetation, encountering the aspen trees in the polyculture first.