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Full-Text Articles in Life Sciences

How Sewage Pollution Affects Distribution And Life History Traits Of The Southern House Mosquito, Culex Quinquefasciatus, Catherine Dean Bermond Dec 2023

How Sewage Pollution Affects Distribution And Life History Traits Of The Southern House Mosquito, Culex Quinquefasciatus, Catherine Dean Bermond

Master's Theses

Eutrophication from wastewater can cause fluxes of nutrients like and carbon and nitrogen in urban waters. One source of nitrogen in freshwater is from untreated sewage discharging from septic tanks. This causes a variety of environmental issues including harmful algal blooms, harming natural predators, and increased production of mosquitoes. Culex quinquefasciatus is the vector of West Nile Virus in St. Tammany Parish, Louisiana. St. Tammany Parish has over 600 miles of septic ditches, which receive effluent directly from aerated treatment units. Culex quinquefasciatus oviposit in polluted waters, and larvae perform well in water with high levels of decomposing organic matter. …


Hide And Seek: An Exploration Of Antipredator And Predator Avoidance Mechanisms In Orthopodomyia Signifera In Response To Predation From Toxorhynchites Rutilus, Nathaniel Dahlberg Jan 2023

Hide And Seek: An Exploration Of Antipredator And Predator Avoidance Mechanisms In Orthopodomyia Signifera In Response To Predation From Toxorhynchites Rutilus, Nathaniel Dahlberg

Master's Theses

There have been many observations of larval Orthopodomyia signifera coexisting with the predator Toxorhynchites rutilus. There are three hypotheses that could explain how Or. signifera resists predation from Tx. rutilus. The first hypothesis states that larvae adapt behavioral changes that limit predation. The second hypothesis states thoracic setae serve as a physical defense that prevents Tx. rutilus from grasping Or. signifera. The third hypothesis states Or. signifera possess a chemical defense indicated by aposematic coloration. To test the first hypothesis larval Or. signifera were exposed to conspecific and heterospecific predation cues and their behavior was observed. Both cues …


Disturbance Ecology Of The Sonadora River Rock Pool Insect Assemblage At Luquillo Experimental Forest, Puerto Rico, Patrick Gilkey Jun 2022

Disturbance Ecology Of The Sonadora River Rock Pool Insect Assemblage At Luquillo Experimental Forest, Puerto Rico, Patrick Gilkey

Master's Theses

Freshwater rock pools can serve as habitat for aquatic insects. Flash-flooding can have profound effects on insect communities in streams and rivers, but these effects have not been studied on freshwater rock pools. The goal of this thesis was to describe ecological patterns of the Sonadora River rock pool insect community at the Luquillo Experiment Forrest, Puerto Rico, specifically in response to intense flash-flooding, and then perform experiments to elucidate possible processes to explain those patterns. The rock pools contained primarily three taxa of Dipteran (true-fly) larvae, in order of decreasing abundance, 1) a newly discovered species of ceratopogonid (biting …


Investigation Of Dna Variability And Phylogenetic Relationships Of Perlesta (Plecoptera: Perlidae) In Mississippi, James C. Valentine, Mac H. Alford May 2022

Investigation Of Dna Variability And Phylogenetic Relationships Of Perlesta (Plecoptera: Perlidae) In Mississippi, James C. Valentine, Mac H. Alford

Master's Theses

The genus Perlesta Banks, 1906 (Plecoptera: Perlidae) consists of 35 species, 33 native to the United States and Canada and two native to China. For over a century these small, brown stonefly adults and freckled yellow nymphs have gone by the name of the type species of the genus, Perlesta placida, but taxonomic work in the genus since 1989 has resulted in the recognition of additional species. These species were mostly recognized and described using morphological characteristics, but two areas that are lacking include (1) linking nymphs to adults and (2) phylogenetic analysis of all species occurring in Mississippi …


Characterization Of The Bacterial Microbiome Of Exotic Tick Species Collected From Migratory Birds, Raima Sen Aug 2021

Characterization Of The Bacterial Microbiome Of Exotic Tick Species Collected From Migratory Birds, Raima Sen

Master's Theses

Migratory birds often serve as natural/accidental hosts to ectoparasites like ticks (predominantly immature stages) and are known reservoirs of several pathogens transmitted by ticks. Parasitizing these birds, exotic tick species often hitch rides to non-native ecological niches, bringing along tick-borne pathogens. This study aims to profile the bacteriome of exotic tick species flying in and out of the US from the Neo-tropical South. A total of 421 tick samples comprised of several different tick species were collected off migratory songbirds at sites north of the Gulf of Mexico (Louisiana State). A 16S rRNA metagenomic multiplexed sequencing approach was used to …


Do Mosquito Pesticides Harm Their Natural Enemies? Ecological Impacts And Non-Target Effects Of Larvicides On Mosquito Predators, Joseph Nelsen Aug 2020

Do Mosquito Pesticides Harm Their Natural Enemies? Ecological Impacts And Non-Target Effects Of Larvicides On Mosquito Predators, Joseph Nelsen

Master's Theses

Larvicides are chemicals used to kill juvenile mosquitoes. When applied to an area, other aquatic organisms are exposed to these chemicals. The removal or impairment of top insect predators could be beneficial to mosquito populations once harmful pesticide levels dissipate. Two common larvicides were examined: growth regulators (IGRs) and surface films (SFs). The goal of this project was to determine if larvicides harm mosquito predators common to southern Mississippi. I surveyed aquatic sites before and after IGR and SF treatments, and then compared changes in insect community structure. Community evenness was lower in SF treated habitats. When analyzing prey taxa …


Mosquito Communities And Insect-Specific Viruses In A Heterogenous, Urban Landscape In Puerto Rico, Nicole Scavo May 2020

Mosquito Communities And Insect-Specific Viruses In A Heterogenous, Urban Landscape In Puerto Rico, Nicole Scavo

Master's Theses

The goal of my thesis was to investigate the relationships between mosquito diversity, Aedes aegptyi populations, and socioeconomic factors (SEF) in an urban setting and to characterize the virome of Ae. aegypti in San Juan, Puerto Rico. Mosquitoes were collected in three periods during late 2018 and early 2019 and were identified to the species level. Socioeconomic factors were measured using foot surveys and U.S. Census data. Some Ae. aegypti females were processed for sequencing and sent to Quick Biology for RNA sequencing to identify viruses. Results showed a link between SEF and Ae. aegypti abundance as well as between …


Characterizing Erad And Antioxidant Response In Ixodes Scapularis Ise6 Cells During Borrelia Infection, Latoyia Downs May 2020

Characterizing Erad And Antioxidant Response In Ixodes Scapularis Ise6 Cells During Borrelia Infection, Latoyia Downs

Master's Theses

Ticks are hematophagous ectoparasites that transmit a multitude of diseases to humans. Borrelia burgdorferi (BB) and Borrelia miyamotoi (BM) are both tick-borne pathogens that cause disease in humans and are transmitted by the black-legged tick (Ixodes scapularis). A byproduct of blood digestion generates reactive oxygen species that are toxic and cause oxidative stress which promotes cellular damage and dysfunction. The endoplasmic reticulum (ER) is especially affected by oxidative stress, resulting in a buildup of improperly folded proteins in the ER lumen called ER stress. To prevent cellular damage, the tick utilizes an antioxidant system to neutralize ROS and mechanisms …


Historical And Contemporary Variables Affecting The Range And Distribution Of Aedes Aegypti, The Yellow Fever Mosquito, In The United States, Nicole Mackey May 2020

Historical And Contemporary Variables Affecting The Range And Distribution Of Aedes Aegypti, The Yellow Fever Mosquito, In The United States, Nicole Mackey

Master's Theses

Aedes aegypti, the primary mosquito vector of the yellow fever virus, threatens global health by passing on this virus, as well as chikungunya, dengue, and Zika viruses. Through its natural tendency to live in highly urban areas and bite human hosts; understanding the factors that affect the historical and current range of the pest is invaluable (Gubler, 1998). Although these viruses are not normally found in the United States, lack of vaccinations and wide-spread presence of the mosquito could lead to these diseases being reintroduced with potentially devastating effects (Monath, 2001). To determine a partial historical range of A. aegypti …


Ecological Stoichiometry: What Role Does It Play In The Competition And Spatial Distribution Patterns Of Aedes Albopictus And Aedes Aegypti?, James Deerman Dec 2018

Ecological Stoichiometry: What Role Does It Play In The Competition And Spatial Distribution Patterns Of Aedes Albopictus And Aedes Aegypti?, James Deerman

Master's Theses

Ecological stoichiometry is the balance of chemical substances within animal bodies through interactions and processes within their ecosystem. Though relatively underexplored, it provides a wealth of information linking interactions across different levels of organization. Detritus is the base of the food web within the small aquatic ecosystems occupied by the mosquitoes Aedes albopictus and Aedes aegypti. Nutrient content of detritus varies, but it can have a negative effect on mosquito growth and survival if nutrient thresholds are not met. I investigated nutrient environments and species abundance in cemetery vases in New Orleans, LA to assess detrital heterogeneity and its …


Elucidating The Molecular Function Of Reprolysin Metalloproteases In Tick-Host-Pathogen Interaction, Jaclyn Bo Williams Aug 2015

Elucidating The Molecular Function Of Reprolysin Metalloproteases In Tick-Host-Pathogen Interaction, Jaclyn Bo Williams

Master's Theses

Ticks are ectoparasites that attach to their host for many days to weeks, feeding to engorgement and continuing their species life cycle. The mechanisms behind the successful feeding and manipulation of host immune responses have been associated with the secretion of their specialized saliva. Tick saliva includes a variety of modulatory molecules that must disrupt and counteract defense mechanisms, including a variety of proteases. Reprolysin Metalloproteases, in the Zn2+ dependent family, is secreted as a proenzyme and is shown to have proteolytic activity, degrading fibrinogen and gelatinase activity, as well as disturbing homeostasis12. Previous work with …


Influence Of Detritus Levels And Organic Pollution On Interspecific Resource Competition, Oviposition Behavior, And Larval Survival Of Two Tire-Inhabiting Mosquito Species (Diptera: Culicidae), David Wayne Allgood Dec 2011

Influence Of Detritus Levels And Organic Pollution On Interspecific Resource Competition, Oviposition Behavior, And Larval Survival Of Two Tire-Inhabiting Mosquito Species (Diptera: Culicidae), David Wayne Allgood

Master's Theses

Mosquitoes (Diptera: Culicidae) are vectors of disease in the adult stage, but understanding the factors affecting distributions of the immature stages is important to the understanding and control of adult populations. Discarded automobile tires comprise important larval mosquito habitats. The Asian tiger mosquito (Aedes albopictus) and the southern house mosquito (Culex quinquefasciatus) are two medically important species commonly found in tires, but factors affecting their larval distributions in tires have not been studied, nor have their interspecific interactions. I investigated the effects of chemicals associated with organic pollution on oviposition preferences and larval survival of both …


Investigating Mechanisms Of Co-Occurrence Between Two Similar Specis Of Predaceous Diving Beetles (Coleoptera: Dytiscidae) In Temporary Aquatic Habitats, Kristopher Alexander Pitcher May 2011

Investigating Mechanisms Of Co-Occurrence Between Two Similar Specis Of Predaceous Diving Beetles (Coleoptera: Dytiscidae) In Temporary Aquatic Habitats, Kristopher Alexander Pitcher

Master's Theses

Predaceous diving beetles (Coleoptera: Dytiscidae) are a model group of organisms for testing coexistence and exclusion mechanisms because numerous species of the family interact in isolated, aquatic habitats, and are ubiquitous throughout landscapes. Two morphologically similar species, laccophilus fasciatus rufus and Laccophilus proximus, co-occur in numerous habitats in South Mississippi, but are hypothesized to have strong interspecific interactions. I investigated several possible mechanisms that may promote such coexistence, including segregation in habitat domain, differences in behavior, and differences in dispersal that may allow co-occurrence between these two species of beetle. Habitat domain and behaviors such as activity and prey consumption …