Objective:
(1) to determine the ratios of resistance to acaricides in Boophilus microplus populations at ranches where field efficacy trials will be conducted; (2) to verify the enhanced toxicity of acaricide mixtures to B. microplus larvae; and (3) to validate the usefulness of acaricide mixtures for the control of acaricide-resistant B. microplus.

Approach:
Drs. Andrew Li and Robert Miller, the ARS PI and Co-PI, will provide detailed experimental protocols and instructions for both the laboratory bioassays and field efficacy trials to Dr. Nicolas Barre, the Co-PI in New Caledonia. Dr. Barre will assess the feasibility of the project regarding the personnel, locations for field trials and the time commitment. The experimental designs will be modified, if necessary, and be finalized. Dr. Barre will be responsible organizing laboratory bioassays, locating proper ranches for field efficacy trials. He will coordinate with the ranchers and his technical staff in assigning animals in test groups, making pre-treatment counts of ticks on animal, preparing acaricide formulations, treating animals, and making post-treatment counts of ticks on animals, collecting, and summarizing experiment data. Dr. Barre will forward experiment data to Drs. Li and Miller. Drs. Barre, Li, Miller and Ronald Davey will be responsible for data analysis, report and manuscript preparations. Dr. John George will provide guidance and oversight to the project, and will also be involved in data analysis and manuscript preparation. Results from this research will be published in a peer-reviewed journal, and will also be provided to APHIS.