In this dissertation I explore the application of two novel modeling techniques for improving risk analysis of vector-borne disease and discuss their potential use in integrating environmental risk assessment that guides environmental and public health decisions. Techniques for analyzing risk have been considered inadequate due to a lack of understanding...
Currently, Sierra Nevada forests have high levels of mortality caused by bark beetles infesting trees stressed by drought, fire, overly dense stands, and pathogens. Fuel loads and fire hazard are high. Past logging and fire exclusion practices are partially responsible for this situation. Mitigative restoration requires thinning overly dense stands,...
The probing behavior and feeding activity of green peach aphid, Myzus persicae
Sulzer, on Bacillus thuringiensis ssp. tenebrionis- transgenic potatoes, insecticide
treated potatoes, and host plants with different preference were electronically
monitored. I found that first, transgenic potatoes had no effect on green peach aphid
probing suggesting that transmission of...
Three species of bacteriophagous nematodes, Pristionchus
lheritieri (Maupas) Paramanov, Pelodera chitwoodi (Bassen)
Dougherty and Rhabditis sp. were studied to determine their potential
roles as vectors of selected insect pathogens, Bacillus thuringiensis
Berliner, Beauveria bassiana (Balsamo) Vuillemin, Metarrhizium
anisopliae (Metchnikoff) Sorokin and a nuclear polyhedrosis
virus of Trichoplusia ni Hubner.
Chlorine...
The improvement of the agricultural and wine-making qualities of the grapevine (Vitis vinifera) is hampered by adherence to traditional varieties, the recalcitrance of this plant to genetic modifications, and public resistance to genetically modified organism (GMO) technologies. To address these challenges, we developed an RNA virus-based vector for the introduction...
Agrobacterium species transform plant cells by targeting a portion of plasmid-encoded bacterial DNA to the host nucleus. Genetic transformation by A. tumefaciens and A. rhizogenes requires secreted effector proteins. The tumor-inducing (Ti) plasmid from virulent A. tumefaciens encodes VirE2, a secreted single-stranded DNA-binding protein required for efficient transformation of hosts....
Important progress in understanding replication, interactions with host plants, and evolution of closteroviruses enabled engineering of several vectors for gene expression and virus-induced gene silencing. Due to the broad host range of closteroviruses, these vectors expanded vector applicability to include important woody plants such as citrus and grapevine. Furthermore, large...
Pyrenophora tritici-repentis (Ptr) is the necrotrophic fungus responsible for tan spot of wheat (Triticum aestivum). Ptr causes disease on susceptible wheat cultivars through the production and secretion of host-selective toxins (HSTs). HSTs are compounds that are only known to be produced by fungi and considered to be primary determinants of...
Trade in live plants has been recognized worldwide as an important invasion pathway for non-native plant pests. Such pests can have severe economic and ecological consequences. Nearly 70% of damaging forest insects and pathogens established in the US between 1860 and 2006 most likely entered on imported live plants. The...