Treesearch

Nucleopolyhedroviruses (NPVs) can initiate devastating disease outbreaks in populations of defoliating Lepidoptera, a fact that has been exploited for the purposes of biological control of some pest insects. A key part of the horizontal transmission process of NPVs is the degradation of the larval integument by virus-coded proteins called chitinases, such as V-CHIA produced by the v-chiA genes. We used recombinant and naturally occurring strains of the Lymantria dispar NPV (LdMNPV) to test horizontal transmission in the field, release of virus from dead larvae under laboratory conditions,...

Gypchek is a gypsy nucleopolyhedrovirus (LdMNPV) product used for management of European gypsy moth (Lymantria dispar dispar L.) in the Unlted States, primarily in areas where the use of broad-spectrum pesticides is not appropriate. Similar LdMNPV products are used in Russia for control of a flighted-female strain of Asian gypsy moth (Lymantria dispar asiatica Vnukovskij), an insect not yet established in the United States. Gypchek is a mixture of LdMNPV genotypic variants and is being developed further toward a single, high-potency genotype product that is effective against both European...

Larval gypsy moths, Lymantria dispar (Lepidoptera:Lymantriidae) were co-infected with the L. dispar nucleopolyhedrovirus (LdMNPV) and the Cotesia melanoscela (Hymenoptera:Braconidae) polydnavirus (CmeBV). CmeBV was given along with a parasitoid egg and calyx products in a stinging event, or in the form of an injection of calyx-derived extract. LdMNPV was delivered per os, integrated into artificial diet. Mortality from all sources was recorded over the subsequent three-week period. Neither parasitism nor injections of purified CmeBV with toxin had any effect on the amount of mortality...

The relationship between large fire occurrence and drought has important implications for fire prediction under current and future climates. This study’s primary objective was to evaluate correlations between drought and fire-danger- rating indices representing short- and long-term drought, to determine which had the strongest relationships with large fire occurrence at the scale of the western United States during the years 1984-2008. We combined 4-8-km gridded drought and fire-danger-rating indices with information on fires greater than 404.7 ha (1000 acres). To account for differences...

Several U.S. state and tribal agencies and other countries have implemented a methodology developed in the arid intermountain western U.S. where short-term (1- to 3-hr) particulate matter (PM) with aerodynamic diameters less than 2.5 µm (PM2.5) concentrations are estimated from an observed visual range (VR) measurement. This PM2.5 concentration estimate is then linked to a public health warning scale to inform the public about potential health impacts from smoke from wildfire. This methodology is often used where monitoring data do not exist (such as many rural areas). This work summarizes...

High-throughput transcriptomics was used to identify Fibroporia radiculosa genes that were differentially regulated during colonization of wood treated with a copper-based preservative. The transcriptome was profiled at two time points while the fungus was growing on wood treated with micronized copper quat (MCQ). A total of 917 transcripts were differentially expressed. Fiftyeight of these genes were more highly expressed when the MCQ was protecting the wood from strength loss and had putative functions related to oxalate production/degradation, laccase activity, quinone biosynthesis,...

Measurements of transient storage in coupled surface-water and groundwater systems are widely made during base flow periods and rarely made during storm flow periods. We completed 24 sets of slug injections in three contiguous study reaches during a 1.25 year return interval storm event (discharge ranging from 21.5 to 434 L s1 ) in a net gaining headwater stream within a steep, constrained valley. Repeated studies over a 9 day period characterize transient storage and channel water from prestorm conditions through storm discharge recession. Although the valley floor was always gaining from...

Forest biomass is a major store of carbon and thus plays an important role in the regional and global carbon cycle. Accurate forest carbon sequestration assessment requires estimation of both forest biomass and forest biomass dynamics over time. Forest dynamics are characterized by disturbances and recovery, key processes affecting site productivity and the forest carbon cycle. Thus, spatially and temporally explicit knowledge of these processes and their drivers are critical for understanding regional carbon cycles. Here, we present a new method that uses satellite data to estimate...

Big sagebrush (Artemisia tridentata Nutt. [Asteraceae]) is an essential component of shrub-steppe ecosystems in the Great Basin of the US, where degradation due to altered fire regimes, invasive species, and land use changes have led to increased interest in the production of high-quality big sagebrush seedlings for conservation and restoration projects. Seedling storage is an important consideration in the production of high-quality planting stock, yet little is known about optimal storage conditions for this species. Our survey of nurseries in western US found that only 13% of those that...

Premise of the study: Flowering phenology is a crucial determinant of reproductive success and offspring genetic diversity in plants. We measure the fl owering phenology of big-leaf mahogany ( Swietenia macrophylla , Meliaceae), a widely distributed neotropical tree, and explore how disturbance from logging impacts its reproductive biology. • Methods: We use a crown scoring system to estimate the timing and duration of population-level fl owering at three forest sites in the Brazilian Amazon over a fi ve-year period. We combine this information with data on population structure and spatial...