2011-08-092011-08-091991https://hdl.handle.net/10365/17474E-1012; Insecticide impregnated ear tags have been the method of choice for horn fly control by many North Dakota cattlemen since the early 1980s. Pyrethroid insecticide resistance in populations of North Dakota horn flies was documented first in 1985. Today many cattlemen in the state face inadequate horn fly control due to increased fly resistance to insecticides.NDSU Agriculture and University Extension: Creative Commons Licensing Deed (http://creativecommons.org/licenses/by-nc-sa/3.0/)Pests -- Control.Livestock productivity.Insect pests.E-1012