Four key aspects of the relationship between predatory hoverflies and the aphid pest Brevicoryne brassicae L. on broccoli were investigated in the Willamette Valley, Oregon USA: 1) the relationship between aphid density and hoverfly oviposition, 2) the larval voracity of key hoverfly species, 3) the preferences of hoverflies and broccoli...
Ceratomyxa shasta is a myxozoan parasite that infects salmonid fishes causing the disease ceratomyxosis that is characterized by severe hemorrhage and necrosis of the intestine and death of the fish host. Ceratomyxa shasta is endemic to the Pacific Northwestern United States and Canada, where epizootics are reported for both wild...
Epichloë typhina (Ascomycetes: Clavicipitaceae) is an endophytic fungus that
infects perennial Pooid grasses and is the causal agent of choke disease. It is endemic
to Europe and was inadvertently introduced into orchardgrass seed production fields in
western Oregon. Choke disease, which was first recorded in Oregon in 1996, currently
infects...
Root rot of sweet corn in western Oregon and Washington is a significant disease that
can reduce yield of intolerant cultivars of processed sweet corn by fifty percent. Root rot
is caused by a complex of soilborne organisms, including Drechslera sp., Phoma
terrestris, and Pythium arrhenomanes. Processors have adopted tolerant...
The hemlock woolly adelgid, Adelges tsugae, is causing widespread mortality of eastern hemlock, Tsuga canadensis, in the eastern United States. In the West, A. tsugae causes negligible damage to western hemlock, Tsuga heterophylla. Host tolerance traits and presence of endemic predators may be contributing to the relative tolerance of western...
A study was conducted in summer of 1973 to assess impact of fluoride-insect damage on radial growth of lodgepole pine near the Anaconda Aluminum Company at Columbia Falls, Montana. Statistically significant growth losses attributed primarily to the effects of fluorides were found in 40 14 of 17 unmanaged stands for...
Landscape heterogeneity is thought to differ among farm management types (i.e. organic and conventional), and this difference is hypothesized to result in variations in pest control by natural enemies. However, it is unclear if these variations in pest control are driven by landscape structure or by farm management practices themselves....
Raspberries have been popular since the time of the ancient Greeks. Red raspberries are cultivated throughout the world, particularly in the Pacific Northwest region of the United States and Canada. The raspberry bushy dwarf virus (RBDV) causes significant reduction in yield and crumbly fruit in raspberries, blackberries and raspberry-blackberry hybrids....
Potato (Solanum tuberosum L.) is the fourth largest food crop in the world following rice (Oryza sativa L.), wheat (Triticum spp.), and maize (Zea mays subs. mays). Potatoes arrived in the United States in the early 1600s and over the following centuries, the crop was subsequently cultivated across the country...
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Spatial analysis of insects and its relationship to pest management