Present and future technologies for tick control.

Arsenic dips were the first effective method for controlling ticks and tick-borne diseases, and were used in many parts of the world for over 50 years before resistance to the chemical became a problem. Until organochlorine products became available about 1946 as alternatives to arsenic, significant losses occurred in cattle herds exposed to arsenic-resistant tick strains. Since the discovery of organochlorines, virtually every chemical group of pesticides developed for the control of arthropods is represented among the list of products employed for the control of ticks on cattle. The evolution of tick resistance to acaricides has been a major determinant of the need for new products. The variety of procedures for treating animals with acaricides ranges from dipping cattle to injecting systemic acaricides, but regardless of the treatment method used, producers need to know and follow proper application procedures to derive maximum benefits. The possibility of stocking with cattle breeds that acquire pronounced resistance to ticks or using recombinant antigen antitick vaccines are the most promising alternatives to acaricides. Most ranchers depend completely on acaricides to control ticks, but do not have access to guidelines on how to make a profit from their tick control program or how to detect and resolve problems with resistance to acaricides. Extension programs are needed to help ranchers manage animal health problems, including how to control ticks and tick-borne diseases.