Life Sciences Commons^™

Biological Control Of The Black Cutworm, Agrotis Ipsilon (Lepidoptera: Noctuidae), And Endophyte Mediated Tritrophic Interactions In Turfgrass, Andrea Jeanne Bixby-Brosi

University of Kentucky Doctoral Dissertations

Components of successful pest management programs must be complementary and not antagonistic. This project examined interactions between natural enemies of the black cutworm, Agrotis ipsilon (Hufnagel), an important turfgrass pest, and host plant resistance by endophytic grass.

Agrotis ipsilon nucleopolyhedrovirus (AgipMNPV) was examined as a bio-insecticide for controlling A. ipsilon in turfgrass. Fresh (1-week-old) AgipMNPV residues killed 76−86% of neonates hatching from eggs on golf course tees, however, residual control of implanted larvae lasted no more than a few weeks. Combinations of AgipMNPV with adjuvants, such as optical brightener and lignin, failed to accelerate or extend …

Morphology And Systematics Of Braconid Wasps, Charles Andrew Boring

University of Kentucky Doctoral Dissertations

The following morphological structures of the ovipositor of Homolobus truncator (Say) (Hymenoptera : Braconidae) are described and hypotheses of their functions are proposed: a series of sharp ridges on the distal surface of the notch helps maintain a grip on the inner surface of the host cuticle; the sperone directs eggs away from the inner surface of the ventral valves; a flap-like structure on each ventral valve covers the portal through which eggs pass; the valvillus maintains position of the egg within the ovipositor and acts against the egg to force it out; ctenidia on the inner surface of the …

Biology And Management Of The Bed Bug, Cimex Lectularius L. (Heteroptera: Cimicidae), Alvaro Romero

University of Kentucky Doctoral Dissertations

The near absence of bed bugs from human dwellings for fifty or more years has left us with limited knowledge of its biology and few answers to eliminate populations. I explored a diverse set of objectives to answer key questions concerning bed bug biology and control. Major objectives were studies of circadian rhythmicity, pyrethroid resistance, sublethal effects of insecticides, synergism of pyrethroids, and evaluation of a pyrrole insecticides, chlorfenapyr. Additional studies included persistence of Borrelia in bed bugs after ingestion, and aggregation factors from feces.

In the absence of host stimuli, insects were much more active in the dark than …

Hymenopteran Molecular Phylogenetics: From Apocrita To Braconidae (Ichneumonoidea), Barbara J. Sharanowski

University of Kentucky Doctoral Dissertations

Two separate phylogenetic studies were performed for two different taxonomic levels within Hymenoptera. The first study examined the utility of expressed sequence tags for resolving relationships among hymenopteran superfamilies. Transcripts were assembled from 14,000 sequenced clones for 6 disparate Hymenopteran taxa, averaging over 660 unique contigs per species. Orthology and gene determination were performed using modifications to a previously developed computerized pipeline and compared against annotated insect genomes. Sequences from additional taxa were added from public databases with a final dataset of 24 genes for 16 taxa.

The concatenated dataset recovered a robust and well-supported topology; however, there was extreme …

The Role Of Spiders In The Detrital Food Web Of An Eastern Deciduous Forest, Erin Elizabeth Hladilek

University of Kentucky Doctoral Dissertations

Historically, terrestrial food web research has focused on describing the structure of aboveground grazing webs, and determining how interactions among plants, herbivores and higher trophic levels influence primary productivity. Detrital food webs however, play a significant role in regulation of ecosystem dynamics through direct impacts on decomposition. Unraveling the complex nature of detrital food web structure is critical to developing a better understanding of ecosystem function. Therefore the primary objective of this research was to describe the structure of the leaf-litter food web in a temperate deciduous forest, with emphasis on interactions between a community of generalist predators, the forest-floor …

Influences Of Host Size And Host Quality On Host Use In A Seed-Feeding Beetle, Angela Rocío Amarillo-Suárez

University of Kentucky Doctoral Dissertations

For insects that develop inside discrete hosts both host size and host quality constrain offspring growth, influencing the evolution of body size and life history traits. This dissertation examines the effects of host size, host quality, and intraspecific competition on life history and associated traits of populations of the seed-feeding beetle S. limbatus adapted to different host plants, and quantifies population differences in phenotypic plasticity. Populations of the study correspond to divergent clades of the species phylogeography (Colombia and United States).

Clades compared differ genetically for all traits when beetles were raised in a common garden. Contrary to expectations from …