Entomology Commons^™

Insecticide Resistance In The Bed Bug, Jennifer R. Gordon

Theses and Dissertations--Entomology

Populations of Cimex lectularius, the bed bug, have resurged around the world posing significant challenges for pest management professionals and causing physical, economic, and emotional strife. Pyrethroid resistance has been found in the vast majority of populations making pest management more difficult. The objectives of my dissertation research were to document the evolution of resistance to pyrethroid and neonicotinoid combination products (called combination products here) and to a neonicotinoid in the laboratory, to record potential fitness costs to resistance to the combination products, and to compare the efficacy of nine insecticides on six populations. In the laboratory, populations of …

Putting Theory Into Practice: Predicting The Invasion And Stability Of Wolbachia Using Simulation Models And Empirical Studies, Philip R. Crain

Theses and Dissertations--Entomology

A new strategy to fight mosquito-borne disease is based on infections of the maternally-transmitted, intracellular bacterium Wolbachia pipientis. Estimates predict that Wolbachia infects nearly half of all insect species, as well as other arthropods and some nematodes. Wolbachia manipulates the reproduction of its host to promote infection, most commonly causing a form of conditional sterility known as cytoplasmic incompatibility. Generally, Wolbachia infections are benign and do not inflict significant costs upon its host. However, studies demonstrate that some infections are associated with substantial costs to its host. These same infections can also induce pathogen interference and decrease vector competency …

Selective Utilization Of Microhabitats By Web-Building Spiders, Kelton D. Welch

Theses and Dissertations--Entomology

Natural enemies are members of complex ecological communities, and their ability to contribute to the biological control of pest organisms is strongly influenced by a convoluted network of ecological interactions with many other organisms within these communities. Researchers must develop an understanding of the mechanisms that shape trophic webs to predict and promote top-down effects of predators. The behavior of predators can have a strong influence on their potential as biological control agents.

Web-building spiders are a useful example organism for the study of natural enemy behavior because of the experimentally tractable nature of their foraging behavior. Specifically, patterns in …

An Assessment Of The Invasive Poison Hemlock And Its Insect Associates In Kentucky, Christine D. Allen

Theses and Dissertations--Entomology

Poison hemlock, Conium maculatum (Apiaceae), is an invasive plant in North America with a unique toxic chemistry. Previous research on this plant has focused on identifying herbivores as potential biological control agents or describing the toxic plant alkaloids. However, none have examined the role of higher trophic levels in the food web surrounding poison hemlock. Generalist predators and food web interactions are an important component of studies investigating invasion effects, as plant or animal introductions can alter ecosystem functioning. In this study, predators in poison hemlock were sampled at the foliar and epigeal levels, resulting in 956 Carabidae and 321 …

Enhancing Beneficial Insect Biodiversity And Biological Control In Turf: Mowing Height, Naturalized Roughs, And Operation Pollinator, Emily Dobbs

Theses and Dissertations--Entomology

The goal of this study was to evaluate several sustainable turf maintenance techniques for their potential to increase beneficial insect populations, which could then provide ecosystem services including pest suppression and pollination. The three techniques in question were 1) raising mowing height in commercial and residential lawns, 2) establishing naturalized roughs on golf courses, and 3) creating pollinator refuges on golf courses through the program Operation Pollinator. We found that raising mowing heights did increase populations of some predators such as spiders and staphylinids, but did not increase predation, which was ubiquitously high because ant populations were unaffected by mowing …

Endosymbiotic Prevalence And Reproductive Manipulation Of The Spider Mermessus Fradeorum, Meghan M. Curry

Theses and Dissertations--Entomology

Spiders are host to a plethora of heritable endosymbiotic bacteria. Broad-taxa screening studies indicate that endosymbionts are particularly common among spiders, however, little is known about how these bacteria affect their spider hosts. In insects these bacteria ensure vertical transmission by either conveying a benefit to the host or manipulating host reproduction to eliminate males that serve as evolutionary dead-ends for maternally-inherited bacteria. Common modes of reproductive manipulation include parthenogenesis, male killing, feminization, and cytoplasmic incompatibility. Screening an assemblage of Mermessus genus spiders, I detected a high frequency and diversity of endosymbiont infection. Within a single species, M. fradeorum …

Effects Of Methoprene On The Survivorship Of Adult Aedes Mosquitoes: A Strategy Or Inactivating Released Mosquitoes, Peter J. Brabant Iii

Theses and Dissertations--Entomology

Methoprene is a Juvenile Hormone (JH) analogue commonly used for the control of mosquito larvae. When applied to a mosquito breeding site, methoprene enters the haemolymph, where it mimics the function of JH and interferes with normal metamorphosis, resulting in larval mortality. Methoprene is commonly used for the control of larvae and has not been used as an adulticide, due to an absence of acute effects. This study evaluated possible chronic effects caused by the exposure of adult Aedes mosquitoes to methoprene. Methoprene was applied, in both technical grade and the commercially available Altosid®, topically to adults through droplet application …

Characterization Of Wolbachia And Its Interaction In Host Mosquitoes, Eunho Suh

Theses and Dissertations--Entomology

Wolbachia are maternally inherited, obligate, intracellular bacteria inducing a form of sterility known as cytoplasmic incompatibility. Wolbachia based strategies have been proposed for the control of disease vectors. One example is to use a population replacement strategy to drive into natural population a novel Wolbachia that modifies the age structure of a vector population, reducing disease transmission.

In this research, the effects of a life-shortening stain of Wolbachia (popcorn Wolbachia) are transferred into the mosquitoes Aedes albopictus (Chapter Two and Three) and A. aegypti (Chapter Four and Five). In Chapter Two, the Wolbachia symbiosis significantly reduced fecundity and …

Systematics Of Ichneutine Parasitic Wasps (Braconidae: Ichneutinae), John Ray Fischer

Theses and Dissertations--Entomology

Ichneutine wasps have received little attention, despite their hypothesized placement at the base of an economically and ecologically important clade, the Microgastroidia s.s. This study combines previous hypotheses based on morphology with molecular evidence from multiple genes (28S: D1-5, 18S, COI, and CAD) to examine phylogenetic relationships of Ichneutinae using maximum parsimony and Bayesian inference. The three main ichneutine groups (Ichneutini, Muesebeckiini, and Proteropini) are each found to be monophyletic, but evidence exists that Ichneutinae itself is paraphyletic with respect to the rest of Microgastroidea s.l. Lispixys is found to be derived from within Oligoneurus, and Masonbeckia is almost …