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The hemlock woolly adelgid, Adelges tsugae Annand, is an invasive species reducing the populations of eastern hemlock, Tsuga canadensis L. Carrière, throughout the eastern United States. Systemic imidacloprid and horticultural oil are the primary chemicals used to control infestations of this invasive pest; however, the impact of these two chemicals on(More)
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(More)
In 2010, thousand cankers disease (TCD) was documented in Tennessee, representing the first confirmation of this disease in the native range of black walnut and the first known incidence of TCD east of Colorado. Tennessee Department of Agriculture personnel conducted surveys to determine the extent of TCD in counties in eastern Tennessee. Samples of(More)
An assessment of the insect guild structure associated with immature and mature eastern hemlock, Tsuga canadensis (L.) Carrière, at high and low elevations was made before the invasion by the hemlock woolly adelgid, Adelges tsugae (Annand), and elongate hemlock scale, Fiorinia externa Ferris. Guild dynamics were determined among 243 insect species(More)
Nontarget feeding of Rhinocyllus conicus Fröelich and Trichosirocalus horridus (Panzer) on native North American thistles in the genus Cirsium has been documented. Some species of these native thistles have shown greater infestation levels of R. conicus in populations that are in close proximity to the target plant species, Carduus nutans L. In 2005 a study(More)
Thousand cankers disease (TCD) is an insect-mediated disease of walnut trees (Juglans spp.) involving walnut twig beetle (Pityophthorus juglandis) and a fungal pathogen (Geosmithia morbida). Although first documented on walnut species in the western U.S., TCD is now found on black walnut (J. nigra) in five states in the eastern U.S. Most collections of P.(More)
American beech gaps in the southern Appalachian mountains are currently threatened by an insect-mediated disease complex known as beech bark disease. Cryptococcus fagisuga Lindinger, or beech scale, a major component of beech bark disease, wounds trees through feeding on vascular tissue through the outer cambium. This feeding method leaves numerous wounds(More)
Rhinocyllus conicus Fröelich was introduced from Europe into North America as a biological control agent of the exotic weed Carduus nutans L. Concern exists over the feeding of this weevil on at least 25 species of native Cirsium thistles. Beginning in 2008, cage studies isolating adults of R. conicus on buds and flower heads of all eight thistle species(More)
Widespread mortality of eastern hemlock, Tsuga canadensis (L.) Carrière, resulting from infestation by hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), has occurred throughout the native range of eastern hemlock within the eastern United States. Imidacloprid, a systemic insecticide, is one of the primary chemical compounds used to(More)
Black walnut, a valuable economic and environmentally important species, is threatened by thousand cankers disease. Systemic imidacloprid and dinotefuran applications were made to mature black walnut trees to evaluate their translocation and concentration levels in various tissue types including leaf, twig, trunk core, nutmeat, and walnut husk. The(More)