The Freehold Area Health Department proposes a multi-faceted approach designed to evaluate the efficacy of selected plant-derived natural products to control tick vectors of Lyme disease, the most common tick-borne illness in the United States. Identification of all-natural, low toxicity chemicals extracted from botanical sources that are toxic to nymphal Ixodes scapularis (Objective 1) through comprehensive reviews of pertinent literature and collaboration with the Department of Forest Products, Oregon State University and the Division of Vector-Borne Infectious Diseases, Centers for Disease Control and Prevention (CDC). Nootkatone showed promise in New Jersey field trials and will be the initial plant-derived acaricide (PDA) tested, but other candidate compounds with proven acaricidal activity and practically available quantities from commercial sources adequate for field testing/bioassay within the time frame of the FOA may be added. Formulation of natural products into water soluble or emulsified compounds that can be applied to vegetation and leaf litter in Lyme disease endemic regions (Objective 2) will be addressed through collaboration with Legacy BioDesign, LLC, Loveland, CO and the CDC. Field studies will test a formulation of a nootkatone-based PDA applied against host- seeking nymphal I. scapularis and Amblyomma americanum using two methods (low pressure vs. high pressure hydraulic sprayers) (Objective 3). Combined dragging and walking survey estimates of tick abundance will be compared between treated plots and untreated edge areas to evaluate whether efficacy is due to direct toxicity or spatial repellency (Objective 4). Trials in the second year of the study will test the relative effectiveness of single vs. multiple applications, the efficacy of additional PDAs, and/or testing of different dosage rates and formulations. The third year of the study will examine the potential role of PDAs in an integrated tick management (ITM) program. A comparative cost analysis will be included in the final year of the study. Assessment of the repellent activity of selected PDAs against host-seeking I. scapularis and A. americanum (Objective 5) will be made in field trials comparing repellency of nootkatone and commercially available products containing deet and permethrin. Treated tick drags and coveralls will be exposed along 100-m transects in known tick-infested habitat during the activity periods of all post-embryonic stages of host-seeking I. scapularis and A. americanum. ? ? ?