Degree Type


Date of Award


Degree Name

Doctor of Philosophy



First Advisor

Joel R. Coats

Second Advisor

Lyric C. Bartholomay


Botanicals have a long history of use for protection against biting arthropods and reducing the risk of exposure to arthropod-transmitted disease agents. The aim of these studies was to characterize the activity of the plant derived sequiterpenes and further develop these compounds as long-lasting botanical repellents and insecticides. Studies addressed the utility of sesquiterpene-rich essential oils from Amyris, Amyris balsamifera, and Siam wood, Fokienia hodginsii, and showed a broad spectrum of activity against arthropods including ticks, cockroaches, house flies and mosquitoes. Identification of the most active components of the Amyris and Siam wood essential oils guided the development of quantitative structure-activity relationship (QSAR) models for predicting repellency to the yellow fever mosquito, Aedes aegypti. The final QSAR models showed good similarity in the trends of selected descriptors, providing support for the importance of physicochemical and electronic parameters in influencing the activity of sesquiterpenes. The effects terpenes and other chemical repellents have on Ae. ageypti mosquito host-seeking behavior were studied in a wind-tunnel system incorporating three different host attractant cues: CO2, lactic acid, and 1-octen-3-ol. Results and methods for expansion of this approach are discussed. Preliminary research on the olfactory neural mechanisms mediating repellency effects in Ae. aegypti, specifically the olfactory receptor gene sequences OR43b and OR83b (VectorBase), is reported.


Copyright Owner

Gretchen Elizabeth Paluch



Date Available


File Format


File Size

142 pages

Included in

Entomology Commons