Submitted to: International Seminar Animal Parasitology Acapulco Mexico
Publication Type: Proceedings
Publication Acceptance Date: October 11, 1995
Publication Date: N/A
Technical Abstract: Horn flies are economically important pests of livestock causing estimated losses in excess of $600 million annually. Formerly, they were controlled with various, nonintensive control procedures. In the mid-1970's, with efforts to increase the efficiency and safety of pesticide usage, ear tags containing pesticides were developed. This method of application reduced pesticide release into the environment in excess of 98% and also greatly increased the efficiency of horn fly control with the new pyrethroid insecticides. Early in the summer of 1982, scientists first became aware of horn fly control problems in the Okeechobee, Florida, area. Producers and laboratory and industry personnel observed that pyrethroid ear tags were no longer giving satisfactory control of the flies. Ten years later, by 1992, resistance had spread throughout the United States, into Canada and Mexico. Resistance developed independently in cattle producing areas rather than spreading from a single foci. This is evidenced by the occurrence in California and Hawaii, considerable distance from the early development in the eastern United States.