Life Sciences Commons^™

Horn Fly Control And Growth Implants Are Effective Strategies For Heifers Grazing Flint Hills Pasture, S. S. Trehal, J. L. Talley, K. D. Sherrill, T. Spore, R. N. Wahl, W. R. Hollenbeck, Dale Blasi

Kansas Agricultural Experiment Station Research Reports

Horn flies (Haematobia irritans (L.)) are considered the most important external parasite that negatively affects pasture-based beef systems with losses estimated to exceed $1 billion annually to the U.S. beef industry. Control strategies have relied heavily on insecticide applications to control horn flies and are implemented when the economic threshold of 200 flies/animal have been exceeded. When horn fly populations are maintained below 200 flies/animal by treating them with insecticides then the level of stress annoyance behaviors such as leg stomping, head throwing, and skin twitching decreases while grazing increases. While most stocker operators utilize some type of fly …