Spatial and temporal distribution of imidacloprid in eastern hemlock in the southern Appalachians.
نویسندگان
چکیده
The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is an exotic insect species dramatically reducing populations of eastern hemlock, Tsuga canadensis (L.) Carrieré, throughout the eastern United States. Systemic imidacloprid is one of the primary chemicals used to successfully control infestations of the hemlock woolly adelgid. The concentration levels for this systemic insecticide present in the sap of eastern hemlocks were evaluated from three strata within the canopy over a two year time span. Enzyme-linked immunosorbent assays were conducted every three months posttreatment to assess imidacloprid concentration within the sap. The effect of application timing (fall versus spring) and application method (soil drench, soil injection, and tree injection) on the translocation of imidacloprid throughout the canopy, and the quantity of imidacloprid translocated in the sap of eastern hemlock branches and the terminal twig and needle tissue was determined. Concentration levels progressively declined from the bottom strata to the top strata of the canopy. This trend was consistent in all chemically treated trees. Tree injections provided the lowest concentration and the most nonuniform distribution of imidacloprid throughout the canopy. The highest insecticide concentrations within the tree across all strata over the two year period were consistently associated with the soil drench method followed by the soil injection method. Imidacloprid concentrations peaked between month 9 and 12 posttreatment, and then declined; however, at two years posttreatment, soil drench and soil injected trees contained concentrations reported as being effective for control of the hemlock woolly adelgid.
منابع مشابه
Spatial and Temporal Distribution of Imidacloprid Within the Crown of Eastern Hemlock
Systemic imidacloprid is the most widely used insecticide to control the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), an exotic pest of eastern hemlock, Tsuga canadensis (L.) Carriére in the United States. This study was conducted to 1) determine the effect of treatment timing (spring vs. fall) and application method (trunk injection vs. soil injection) on the spatial a...
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The hemlock woolly adelgid (HW A; Adelges tsugae Annand) is causing widespread decline and mortality of eastern hemlock (Tsuga canadensis (L.) Carr.) throughout most of the range of eastern hemlock. Stem injection of insecticide is widely used as a chemical control measure, but the effectiveness of this method depends on the hydraulic characteristics of individual trees. We present data quantif...
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ورودعنوان ژورنال:
- Journal of economic entomology
دوره 103 2 شماره
صفحات -
تاریخ انتشار 2010