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Full-Text Articles in Life Sciences

Boxwood Dieback: Molecular Detection, In-Vitro Fungicide Efficacy, And Host Susceptibility For Managing A New Emerging Disease Caused By Colletotrichum Theobromicola, Harleen Kaur Nov 2020

Boxwood Dieback: Molecular Detection, In-Vitro Fungicide Efficacy, And Host Susceptibility For Managing A New Emerging Disease Caused By Colletotrichum Theobromicola, Harleen Kaur

LSU Master's Theses

Boxwood (Buxus spp. L) is one of the most common and widely planted perennial ornamentals in both home gardens and commercial landscapes. Grown for its evergreen, dark green foliage, boxwood cultivation dates back to 4000 BC in Egypt. Although considered hardy, boxwood is susceptible to several plant pathogens. Recently reported boxwood dieback, a fungal disease caused by Colletotrichum theobromicola, has been spreading at an alarming rate within the United States. Boxwood dieback consists of symptoms that resemble to those caused by Phytophthora root rot, Volutella blight, and some abiotic disorders and can be easily misdiagnosed in nurseries and …


Ecology Of The Roseau Cane Scale (Nipponaclerda Biwakoensis, Hemiptera: Aclerdidae) In Coastal Louisiana, Leslie Alejandra Aviles Lopez Jul 2020

Ecology Of The Roseau Cane Scale (Nipponaclerda Biwakoensis, Hemiptera: Aclerdidae) In Coastal Louisiana, Leslie Alejandra Aviles Lopez

LSU Master's Theses

Common reed, Phragmites australis, is the dominant plant in the Mississippi River Delta (MRD), Louisiana. Phragmites australis stands reduce soil erosion from wave action, protect the oil infrastructure, and freshwater habitats. In the fall of 2016, widespread reed die-backs in the MRD were associated with outbreaks of an invasive scale Nipponaclerda biwakoensis (Hemiptera: Aclerdidae). Due to the recent detection of the scale, there was limited knowledge of its ecology in the adventive range, and its impacts on P. australis lineages. Therefore, the objectives of my thesis were to determine (1) the host specificity of the N. biwakoensis in important economic …


Specialization And Trade-Offs In Plant-Feeding Insects, Daniel Peterson Nov 2017

Specialization And Trade-Offs In Plant-Feeding Insects, Daniel Peterson

Doctoral Dissertations

The immense diversity of life on Earth has been attributed to the partitioning of available resources into ecological niches, but it is not obvious what determines the niche size of each species. For example, most plant-feeding insects consume only one or a few closely-related host-plant species despite the advantages of having a broader diet. Many researchers have therefore suggested that the evolution of broad diets in plant-feeding insects must be constrained by genetic trade-offs between adaptations to alternative host-plants. Despite its intuitive feel, however, little empirical evidence in support of the trade-off hypothesis has emerged from decades of experimental studies …


Biology And Ecology Of Crapemyrtle Bark Scale, Acanthococcus Lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), Zinan Wang Jan 2017

Biology And Ecology Of Crapemyrtle Bark Scale, Acanthococcus Lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), Zinan Wang

LSU Master's Theses

The crapemyrtle bark scale, Acanthococcus lagerstroemiae (Kuwana) (Hemiptera: Eriococcidae), is an exotic pest on crapemyrtles, Lagerstroemia spp. (Myrtales: Lythraceae). Because of its recent arrival in the US, little is known about its biology and ecology. The purpose of my thesis was to improve the knowledge about A. lagerstroemiae in four aspects involving its thermal tolerance, physiological adaptations to cold temperatures, temperature-dependent development and host range. Thermal tolerance was determined to understand how temperature extremes constrain the distribution of A. lagerstroemiae in the US. Results suggested that A. lagerstroemiae can tolerant high heat, but its potential distribution to the northern US …


Elucidating The Factors That Modulate The Distribution Of Avian Haemosporida Parasites Across A Community Of Hosts, Matthew Christopher Ikaika Medeiros Dec 2013

Elucidating The Factors That Modulate The Distribution Of Avian Haemosporida Parasites Across A Community Of Hosts, Matthew Christopher Ikaika Medeiros

Dissertations

Parasites are heterogeneously distributed across host species, host populations, and host individuals within populations. A primary aim of infectious disease ecology seeks to uncover the factors that drive this heterogeneity. At a fundamental level, host infection is determined by exposure and susceptibility to a pathogen. My dissertation explores how evolutionary and ecological forces associated with these fundamental determinates of infection shape variation in parasite host breadth and host infection status. Here, I focus on a community of vector-borne avian Haemosporida parasites among suburban birds of Chicago, IL. These parasites exhibit strong variation in their distribution among available hosts, and provide …


Modulators Of Symbiotic Outcome In Sinorhizobium Meliloti, Matthew B. Crook Mar 2013

Modulators Of Symbiotic Outcome In Sinorhizobium Meliloti, Matthew B. Crook

Theses and Dissertations

Microorganisms interact frequently with each other and with higher organisms. This contact and communication takes place at the molecular level. Microbial interactions with eukaryotes can be pathogenic or mutualistic. One of the best-studied symbioses is the complex interaction between nitrogen-fixing soil bacteria, termed rhizobia, and legumes. This symbiosis culminates in the elaboration of a new organ, the root nodule. Many of the molecular signals exchanged between the host plant and the invading rhizobia have been deduced, but there is still much that remains to be discovered. The molecular determinant of host range at the genus level of the plant host …