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Susceptibility Of Adult Colorado Potato Beetle (Leptinotarsa Decemlineata) To The Fungal Entomopathogen Beauveria Bassiana, Ellen Klinger Aug 2003

Susceptibility Of Adult Colorado Potato Beetle (Leptinotarsa Decemlineata) To The Fungal Entomopathogen Beauveria Bassiana, Ellen Klinger

Electronic Theses and Dissertations

Factors influencing the susceptibility of adult Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), to the fungal entomopathogen, Beauveria bassiana (Bals.), were studied. In an assay comparing trials between a): laboratory reared, non-diapausing beetles and b): field collected, post-diapausing beetles, survival of B. bassiana treated beetles was higher for non-diapausing adults, however, control mortality was higher for post-diapausing adults. In a similar assay with field collected pre- and post-diapausing beetles, survival of B. bassiana treated individuals was higher for post-diapause adults and control mortality was higher for post-diapausing adults than pre-diapausing beetles. In a third experiment, the effect of time from ...


The Short And Long-Term Effects Of Herbicide Application In Maine Clearcuts On Ant Communities (Hymenoptera: Formicidae), Kerry Frances Lough May 2003

The Short And Long-Term Effects Of Herbicide Application In Maine Clearcuts On Ant Communities (Hymenoptera: Formicidae), Kerry Frances Lough

Electronic Theses and Dissertations

The short and long-term effects of glyphosate application on the diversity and abundance of ants in Maine clearcuts was assessed in a two-year study. Glyphosate is applied to release coniferous trees from suppression by competition with deciduous vegetation after a forest is clearcut. Previous research indicates glyphosate has limited immediate and long-term effects on non-target fauna, though specific species can be affected. Limited research on the effects of herbicides on insects indicates some initial decrease in insect populations. Beneficial insects, such as pollinators and predators, positively influence the forest ecosystem, but little research has examined the effects of herbicide application ...


Ten Years Of Change In Beech Stand In North Central Maine Long Affected With Beech Bark Disease, Amanda Farrar Jan 2003

Ten Years Of Change In Beech Stand In North Central Maine Long Affected With Beech Bark Disease, Amanda Farrar

Electronic Theses and Dissertations

In Maine, northern hardwood stands long affected by beech bark disease often still have high numbers of beech trees. This is mostly due to sprouting, and most new stems become severely infected with the disease. Beech that are resistant to the scale insect, Cryptococcus fagisuga Lind., the inciting factor for the disease complex, do exist and often occur in clumps of root sprout origin. In 1989 a long-term study of the effects of commonly used seasonal harvesting regimes on regeneration initiation and survival was established in north central Maine. Treatments included harvest season (winter or summer) and intensity (clearcut or ...


Variation In The Severity Of Mummy Berry Disease Among Lowbush Blueberry Clones, Laura Penman Jan 2003

Variation In The Severity Of Mummy Berry Disease Among Lowbush Blueberry Clones, Laura Penman

Electronic Theses and Dissertations

Lowbush blueberry production is important for the economy of Maine and the Maritime provinces, and mummy berry disease, caused by Monilinia vaccinii- corymbosi, often reduces plant stand vigor and fruit production. The severity of mummy berry disease among clones of lowbush blueberry were measured in four fields over a two year period (2001 and 2002). In each of 37 clones,lO flowering stems with and without symptoms of blight were randomly selected at flowering to represent "diseased" and "healthy" stem populations, respectively. The severity of leaf and flower blight and fruit mummification was measured for each of these stems, and ...


Effect Of Stand Density On Behavior Of Leaf Area Prediction Models For Eastern White Pine (Pinus Strobus L.) In Maine, Micah D. Pace Jan 2003

Effect Of Stand Density On Behavior Of Leaf Area Prediction Models For Eastern White Pine (Pinus Strobus L.) In Maine, Micah D. Pace

Electronic Theses and Dissertations

There is little debate within the forest science community that leaf area (LA, the surface area of live foliage) or leaf area index (LAI, the total surface area of live foliage per unit of ground area) are important variables, central to enhancing the understanding of forest growth and many forest ecosystem processes. The ability to accurately measure LA1 has become a research priority and has resulted in various methods of estimation for a variety of species and regions. In this study LA estimation models for Pinus strobus L. were developed, tested, and compared across a wide range of densities for ...


Effects Of Biological Control And A Ryegrass Rotation On Rhizoctonia Disease Of Potato, Marin Talbot Brewer Jan 2003

Effects Of Biological Control And A Ryegrass Rotation On Rhizoctonia Disease Of Potato, Marin Talbot Brewer

Electronic Theses and Dissertations

Rhizoctonia solani is an important pathogen of potato capable of reducing tuber yield and quality. Integrated, sustainable methods including biocontrol and effective crop rotations are necessary for control of this pathogen. Twenty-eight potential biocontrol organisms were tested for efficacy against R. solani on potato in a series of greenhouse trials. Organisms tested consisted of field isolates of Paenibacillus polymyxa, Pseudomonasfluorescens, Penicillium sp., Trichoderma sp., and Rhizoctonia zeae; known biocontrol isolates including Laetisaria arvalis, Verticillium biguttatum, Cladorrhinumfoecundissimum, and Stilbella aciculosa; and commercial products of Bacillus subtilis (Kodiak), Trichoderma virens (SoilGard), and Trichoderma harzianum (Rootshield). Different formulations and rates of several fungal ...