Oliver Eshun


Elucidating characteristics of mosquito-host interactions are critical for understanding the ecology and epidemiology of mosquito-borne diseases. In this dissertation, I conducted three studies to explore potential mosquito-host interactions and associated virus infection rates. I first demonstrated that mosquito captures at CO2-baited traps decreased most markedly with height above ground, and also decreased with distance from water at a riparian area but not at an open water source lacking a vegetated border. Birds might therefore prefer elevated nests or roosts to avoid mosquitoes. The second study examined the anti-mosquito behaviors of budgerigars (Melopsittacus undulatus) in a laboratory study. The birds defended themselves by increased frequencies of at least five maintenance behaviors, especially foot shake. These behaviors increased over a 2-hour period of exposure, and varied depending on mosquito landing location. Mosquitoes landed primarily on the trunk of birds, but showed no preference for fresh versus previously exposed birds. The third study showed that primary serum antigenantibody tests were negative in rattlesnakes (genus Crotalus) for West Nile virus and western equine encephalitis, but positive for a flavivirus presumed to be St. Louis encephalitis in 10% of the 40 sampled snakes. This unexpected finding constitutes the first likely report of St. Louis encephalitis virus in any reptile, and suggests that rattlesnakes may be reservoirs or secondary hosts of flaviviruses in southern California. Collectively, these studies provide new insights on mosquito host-seeking behavior, mosquito-host interactions, and viruses in reptiles, and offer direction for further study.

LLU Discipline



Basic Sciences


School of Medicine

First Advisor

Hayes, William K.

Second Advisor

Dunbar, Stephen G.

Third Advisor

Gerry, Alec C.

Fourth Advisor

Sinclair, Ryan

Fifth Advisor

Uppala, Padma

Degree Name

Doctor of Philosophy (PhD)

Degree Level


Year Degree Awarded


Date (Title Page)




Library of Congress/MESH Subject Headings

Environmental Health; Host-Parasite Relations; Mosquitoes; Mosquitoes as carriers of disease - Epidemiology;

Subject - Local

Flaviviruses; Southern California; Rattlesnakes;



Page Count


Digital Format


Digital Publisher

Loma Linda University Libraries

Usage Rights

This title appears here courtesy of the author, who has granted Loma Linda University a limited, non-exclusive right to make this publication available to the public. The author retains all other copyrights.


Loma Linda University Electronic Theses and Dissertations

Collection Website


Loma Linda University. Del E. Webb Memorial Library. University Archives