Influence of Imidacloprid and Horticultural Oil on Spider Abundance on Eastern Hemlock in the Southern Appalachians.

摘要: Hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is an exotic pest of eastern hemlock, Tsuga canadensis (L.) Carriere (Pinales: Pinaceae), in the United States. Two commonly used insecticides to manage adelgid are imidacloprid, a systemic neonicotinoid insecticide, and horticultural oil, refined petroleum oil foliar spray. We have investigated influence imidacloprid on spider abundance at different canopy strata hemlock. In total, 2,084 spiders representing 11 families were collected from canopies beat-sheet direct observation samples, Theridiidae, Araneidae, Salticidae, Anyphaenidae most abundant. Significantly higher numbers recorded untreated control trees compared with treated using soil drench injection applications. Spider injected applications did not significantly differ trees. was greater top middle than bottom stratum, where concentrations highest. Regression analysis showed that inversely associated concentration. This research demonstrates when applied selected methods, has potential result reductions densities strata. However, slight may be acceptable short-term ecological impact loss hemlock all benefits it provides. Future studies should include investigations long-term