Agriculture Commons^™

Optimizing Monarch Butterfly And Bee Conservation Efforts In The Urban Landscape, Adam M. Baker

Theses and Dissertations--Entomology

The eastern migratory population of monarch butterflies (Danaus plexippus) is in serious decline. Most of the efforts to conserve this iconic insect focus on habitat restoration in the US Midwest. Often overlooked are small butterfly-centric gardens that can act as stepping stones between urban and rural areas. These studies aim to optimize the conservation value of such gardens.

Eight milkweed (Asclepias) species varying in height, form, and leaf shape were compared over two years in a common-garden experiment. I measured milkweed growth, rhizome spread, and bloom periods, conducted bi-weekly counts of monarch eggs and larvae, evaluated …

Epigenetic Regulation Of Hormone Action In The Red Flour Beetle, Tribolium Castaneum (Herbst), Smitha George

Theses and Dissertations--Entomology

Hormones are the chemical communication signaling molecules released into the body fluid to stimulate target cells of multicellular organisms. Two major hormones, ecdysteroids (20-hydroxyecdysone, 20E) and juvenile hormones (JH), regulate a wide variety of physiological and developmental processes in insects. Therefore, hormones have been extensively studied and are attractive targets for the development of target-specific insect control methods. Recent studies suggest that epigenetics adds another layer of regulation to explain multiple functions of the same circulating hormone in different tissues and at various time points. In my dissertation, I focused on a major post-translational modification, ‘acetylation,’ to elucidate the epigenetic …

Aggregation Behavior In The Bed Bug, Cimex Lectularius L., Paul D. Baker

Theses and Dissertations--Entomology

The bed bug, Cimex lectularius L., is a common household pest that feeds on the blood of its human hosts. Unlike many other hematophagic arthropods, bed bugs have not demonstrated the ability to vector disease; yet its presence in a household often leads to fear and anxiety amongst its human host victims. Bed bugs spend the majority of their time aggregating in enclosed and hidden locations, making it difficult to detect and eradicate them. One of the significant mediators of aggregation behavior is an aggregation pheromone. The pheromone has been identified to be six chemical compounds, five volatile compounds that …

Developing Alternative Practices For Management Of Flea Beetles Attacking Eggplant And Leafy Brassicaceous Greens, Robert Brockman

Theses and Dissertations--Entomology

Flea beetles are a challenging pest for many producers of vegetable crops in Kentucky. Chewing numerous small holes in the leaves of their host plants, high flea beetle populations can quickly overwhelm unestablished crops. I tested the efficacy of several alternatives to insecticides within brassicaceous leafy greens and eggplant. Four field trials in 2019 and 2020 compared essential oil sprays, the woven-mesh row cover ProtekNet, the spunbonded row cover Agribon, and reflective silver mulch to an untreated control, a conventional insecticide rotation of dinotefuran and pyrethroids, and an organic insecticide rotation of spinosad and pyrethrins. The silver reflective mulch was …

A Tangled Web: The Dynamics Of Endosymbiotic Infections In A Linyphiid Spider, Laura Cecilia Rosenwald

Theses and Dissertations--Entomology

Many arthropods are infected with bacterial endosymbionts that manipulate host reproduction, but few bacterial taxa have been shown to cause such manipulations. Mermessus fradeorum (Linyphiidae) is a sheet-weaving spider that displays both feminization and cytoplasmic incompatibility (CI). To correlate reproductive manipulations to endosymbionts, I surveyed the bacterial community of M. fradeorum using high throughput sequencing and found that individuals can be infected with up to five different strains of bacteria from the genera Wolbachia, Rickettsia, and Rickettsiella. Rickettsiella was found in all 23 tested spider matrilines. I used antibiotic curing to generate uninfected matrilines that I reciprocally crossed with …

Management Of Stink Bugs (Hemiptera: Pentatomidae) On Soybean In Kentucky, Yaziri Gonzalez

Theses and Dissertations--Entomology

Phytophagous stink bugs (Hemiptera: Pentatomidae) are pests of significant importance to soybean, Glycine max (L.), because they can cause severe losses in seed quality, ultimately affecting yield. Damage to soybean is caused through a process called extra-oral digestion. This occurs when the adults and nymphs of stink bugs pierce plant tissues with their mandibular and maxillary stylets, insert digestive enzymes, break down tissue, and extract the digested plant fluid. Three endemic stink bug species of North America are present in Kentucky: green stink bug (Chinavia hilaris), brown stink bugs (Euschistus species complex), and red-shouldered stink bug (Thyanta custator) …

Management Of Sugarcane Aphid (Melanaphis Sacchari) Using Biological And Cultural Tactics In Kentucky, Nathan Harriman Mercer

Theses and Dissertations--Entomology

In 2013, a new aphid pest of sorghum, the sugarcane aphid Melanaphis sacchari Zehntner (Hemiptera: Aphididae), was found in the southern US, and caused significant yield loss in sorghum. Since then, M. sacchari has spread to most of the sorghum growing regions. Unmanaged populations can cause complete crop loss in grain, forage and sweet sorghum. M. sacchari cannot survive winters without a live plant tissue and must recolonize much of its pest range annually. Sweet sorghum (Sorghum bicolor) is an important crop for many growers in Kentucky, producing $16-25 million a year from its syrup. Biological control of …

Identification And Characterization Of Epigenetic Regulators In The Yellow Fever Mosquito, Aedes Aegypti, Shankar C. R. R. Chereddy

Theses and Dissertations--Entomology

Due to the increased interactions between the sylvatic and urban cycles of Aedes aegypti life cycle, there has been an increase in the incidence of vector-borne diseases. The risk involved through the transmission of viruses like Dengue, Zika, Yellow-fever and Chikungunya calls for an effective control method for the deadly vector. The possibility of pesticide resistance and the costs involved in producing new pesticides have pushed Sterile Insect Technique (SIT) into prominence. However, current methods used to sterize insects for SIT are not highly efficient. This study tackles current issues in mosquito control by identifying and characterizing epigenetic regulators that …

Dynamic Balancing Of Foraging And Defensive Effort Contribute To The Optimality Of The Honey Bee Robbing Strategy, Grayson James Grume

Theses and Dissertations--Entomology

The optimality of a foraging strategy shifts in response to dynamic ecological conditions and the need to devote effort to other tasks. Nest defense and foraging effort in the honey bee may trade off as both tasks are performed by a shared workforce of physiologically-specialized individuals in exclusive roles. Honey robbing is a foraging strategy predicted to benefit from simultaneous increases in foraging and defensive effort, but may be constrained by workforce specialization. We developed a methodology to induce robbing behaviors with uninhabited bait hives. We used this methodology to evaluate foraging and defensive effort before and during robbing by …

Physiological Ecology Of Overwintering And Cold-Adapted Arthropods, Leslie Jean Potts

Theses and Dissertations--Entomology

Given their abundance and diversity, arthropods are an excellent system to investigate biological responses to winter. Winter conditions are being majorly impacted by climate change, and therefore understanding the overwintering biology of arthropods is critical for predicting ecological responses to climate change. In Chapters 2 and 3, I investigate the winter biology of a winter-active wolf spider. I show that winter-active spiders can take advantage of periodic prey resources and grown in the winter, which may allow them to get a jumpstart on spring reproduction. I also investigate spiders’ ability to track changes in their environment by quantifying low temperature …