Degree Type


Date of Award


Degree Name

Doctor of Philosophy




Entomology; Toxicology

First Advisor

Joel R. Coats

Second Advisor

Lyric C. Bartholomay


With insecticide resistance to older insecticidal chemistries becoming ever more prevalent in wild insect populations, it is imperative to continually develop new insecticidal technologies. Plant essential oils and their constituent terpenoids represent promising insecticidal agents and insecticide additives to be used in the future. This dissertation categorizes the toxicity of a wide variety of plant essential oils against Aedes aegypti and Anopheles gambiae, both of which are important vectors of a number of debilitating viruses and parasites. We continue this research by evaluating the degree to which these plant essential oils act to enhance/synergize various pyrethroids and other insecticides against these species, as well. This work is then complemented by an exploration of the activity of numerous plant terpenoids screened against a cell line stably expressing an octopamine receptor isolated from the American cockroach. The activity of these terpenoids at this receptor is then related to whole organism in vivo toxicity in American cockroaches. Finally, we explore the ability of biodegradable micro- and nanoparticles to localize within specific tissues in Aedes aegypti mosquitoes to evaluate their potential to carry novel insecticidal molecules across the insect cuticle into select target tissues. Through these explorations, this dissertation aims to contribute to the body of knowledge directed toward understanding the modes and mechanisms of action of plant terpenoids and to strategize new approaches for delivering these and other insecticidal molecules in future insecticide formulations.

Copyright Owner

Edmund John Norris



File Format


File Size

259 pages