Date of Award
Doctor of Philosophy (PhD)
Holly D. Gaff
Wayne L. Hynes
R. Jory Brinkerhoff
Tick-borne diseases continue to increase in the United States, and yet no comprehensive method of tick control currently exists. The lone star tick, Amblyomma americanum, is an aggressive human-biting tick and vector of several pathogens which effect both humans and other animals. Standard control methods do not work as well for A. americanum as they do for the more commonly studied blacklegged tick, Ixodes scapularis. TickBot, a tick-killing robot, is a potential method to control A. americanum that lures ticks to its path with carbon dioxide and the ticks die from contact with a permethrin-treated cloth that is dragged behind. Another method proposed as a biological control of ticks are helmeted guinea fowl, Numida meleagris. However, N. meleagris are also potential hosts of A. americanum. To better understand the ecological dynamics underlying tick control methods, mathematical models can be used to replicate field studies. The purpose of this dissertation was to study the effect of two control methods, the TickBot and N. meleagris, and their effect on A. americanum both in the field and through agent-based modeling. A review of previous studies found that no control method works well for all species and all life stages. Few methods exist that are effective in controlling A. americanum without broadcasting acaricide, which can have negative effects on the environment. This suggested that integrated tick management (ITM) systems are the best option for controlling ticks. The first study of N. meleagris and A. americanum found that N. meleagris provided some reduction in nymph densities, but N. meleagris were also found to be hosts of A. americanum nymphs. An agent-based model was developed to assess the use of the TickBot and extended to also include N. meleagris as an ITM. The TickBot model found the best treatment scenario was running the TickBot three times a week with carbon dioxide.The ITM model that included both TickBot and N. meleagris had unclear efficacy with addition of the biological control that can also be a host. Overall, more research is needed to find an effective ITM of A. americanum, as well as other tick species.
White, Alexis L..
"Tick Control Methods for Amblyomma americanum, in Virginia: Applications and Modeling"
(2019). Doctor of Philosophy (PhD), Dissertation, Biological Sciences, Old Dominion University, DOI: 10.25777/x6j1-zv51
Available for download on Wednesday, February 02, 2022