Life Sciences Commons^™

Influence Of The Annual Flood Pulse Of The Atchafalaya River And Updates On The Ecology Of Floodplain Aquatic And Semi-Aquatic Hemiptera And Their Associates, Patricia Ls Wooden

LSU Master's Theses

Understanding the biodiversity of insects in an area provides key insights into the health and uniqueness of an ecosystem. Here we increase the breadth of knowledge of Louisiana aquatic Hemiptera through field and natural history collection research. The Atchafalaya River floodplain is variably inundated throughout the course of the year, peaking with the spring flood pulse, resulting in spatiotemporally dynamic habitats for aquatic organisms. Buffalo Cove Water Management Unit (BC) is within the river system, whereas Lake Fausse Pointe (LFP) has been leveed from the influence of the river for over 50 years. We collected aquatic macroinvertebrates with quatrefoil light …

Determining The Presence Or Absence Of Euscepes Postfasciatus In Haiti And Use Of Molecular Markers For The Distinction Of Cylas Formicarius Elangantulus Biotypes, Marie Rachele Lexidort

LSU Master's Theses

Cylas formicarius elegantulus (Summers) and Euscepes postfaciatus (Fairmaire) are the most destructive sweetpotato weevils in the Caribean Basin. However, damage occurring in sweetpotato production in Haiti is attributed to C. formicarius (S), since it is known to be the most prevalent species while, conflicting information is available pertaining to the occurrence of the E. postfaciatus (F). This study was conducted in the summer of 2018 to determine the presence or absence of E. postfaciatus (F) in Haiti. 98 weevil samples from field (70% ) and infested sweetpotato roots from field and regional markets were collected (30%) in the most relevant …

Effects Of Virus Infection And Volatiles On Aphid Virus Vector Behavior On Sweetpotato, John Lawrence Dryburgh

LSU Doctoral Dissertations

Sweetpotato is affected by a wide variety of viruses worldwide, which can cause yield losses of up to 90%. Many of these viruses are transmitted by aphids in a non-persistent manner. Non-persistent viruses are acquired and transmitted within minutes, and thus conventional control, such as insecticides, are ineffective. Altering aphid movement and feeding behavior may affect the rate of virus transmission. One potential method to alter aphid behavior is volatile organic compounds (VOC), including volatiles emitted by virus infected plants, plant hormones, and commercial control agents. Aphid movement near sweetpotato fields was monitored to determine trends throughout the growing season. …

The Role Of Atp-Sensitive Inward Rectifier Potassium Channels In The Regulation Of Reactive Oxygen Species In The Western Honey Bee, Apis Mellifera L., Christopher J. Fellows

LSU Master's Theses

Colonies of managed honey bees are annually being lost at an unsustainable rate, partly due to reduced immunocompetence that leads to acute viral outbreaks and mortality. To aid in restoring honey bee health despite the myriad of environmental stressors, this thesis focuses on identifying novel physiological pathways that can mitigate virus-mediated mortality through increased immune function. Previous work has demonstrated that a family of potassium ion channels, termed K_ATP channels, mediate the survival of honey bees during infection from a model virus, suggesting K_ATP channels may drive antiviral immunity. Interestingly, these channels have been linked to the regulation …

Physiological Characterization Of Inward Rectifier Potassium (Kir) Channels In Insect Neural Systems, Rui Chen

LSU Master's Theses

A complete understanding of the physiological pathways critical for proper function of the insect nervous system is still lacking. The recent development of potent and selective small-molecule modulators of insect inward rectifier potassium channels has enabled the interrogation of the physiological role and toxicological potential of Kir channels within various insect tissue systems. Therefore, we aimed to highlight the physiological and functional role of neural Kir channels in the central nervous system, muscular system, and neuromuscular system through pharmacological and genetic manipulations. Our data provide significant evidence that Drosophila neural systems rely on the inward conductance of K+ ions for …

Effects Of Plant Viruses On Vectors And Non-Vector Herbivores In Three Different Pathosystems, Sunil Paudel

LSU Doctoral Dissertations

Plant viruses are an important component of agro-ecosystems and the knowledge of impacts they can cause on their hosts, and on different vectors and non-vector herbivores associated with the hosts, is very crucial in devising sound management strategies for virus disease and vector control in the landscape. The interactions between these components, however, are difficult to predict and vary according to the system under investigation. In order to understand some of these interrelationships, different sets of experiments were carried out in three different pathosystems to look at the impacts of plant viruses on vector and non-vector herbivores. Firstly, in Sorghum …

Mosquito Image Classification Using Convolutional Neural Networks, Sumanth Vissamsetty

LSU Master's Theses

Human life has always been affected by insects, especially mosquitoes, since it's early beginnings. This pesky insect acts as a vector that transmit pathogens through feeding on our blood, spreading life-threatening diseases like Zika Virus, Malaria, Dengue fever, Chikungunya and more. It is important to prevent these mosquitoes from harming humans and one way to do so is to control the mosquito population, or mosquito abatement as it is commonly known. It is important to note that not all mosquitoes are the same and each of them live, reproduce and attack in their own unique way. Hence it is crucial …

Effects Of Dietary Sugars And Sugar Alcohols On Mortality And Thermal Tolerance In Culex Quinquefasciatus And Aedes Aegypti, Madeleine Chura

LSU Master's Theses

Aedes aegypti (L. 1762), the yellow fever mosquito, and Culex quinquefasciatus Say 1823, the southern house mosquito, are prevalent in tropical and subtropical areas worldwide and are responsible for the spread of a number of devastating diseases to humans and livestock. The development of new control methods, as well as continued study of mosquito biology, is vital for improving human health. This study aimed to examine the efficacy of sugar alcohols as a novel means for mosquito control, as well as how sugar alcohols and other factors are involved in thermal tolerance in mosquitoes.

No-choice tests with the sugar alcohols …

The Tripartite Interaction Between Arbuscular Mycorrhizal Fungi, Rice, And Insects, Lina Bernaola Alvarado

LSU Doctoral Dissertations

Losses caused by pests remain an important limitation to achieving high rice yields in the United States. Arbuscular mycorrhizal fungi (AM fungi) are able to modify plant physiology by increasing plant growth or inducing defense responses against insect herbivores. However, studies of the role of AM fungi in agroecological factors, including natural occurrence, plant resistance, soil dependency, and plant tolerance, with specific regards to pests that feed on rice plants have not been conducted before. A three-year study revealed natural occurring colonization by AM fungi on rice roots sampled in four rice-producing areas in the southern United States. Overall, rice-AM …