Purdue University	Publication E-12
Cooperative Extension Service	April, 1966
Department of Entomology
How to Control Flies in Barns and on Cattle
Several kinds of flies live around farm buildings or attack cattle. Those in buildings are usually house flies, although blow flies and the lesser house fly are common. These flies do not feed on cattle but annoy them. Except for the face fly, those that feed on animals are blood suckers. Most prevalent is the horn fly. In addition, there are the stable fly (sometimes called "biting house fly"), mosquitoes, and several kinds of horse flies. Face flies do not pierce the skin, but feed upon secretions from the
eyes, nostrils and upon wounds, including those made by blood sucking flies.
A continuous, thorough sanitation program is the most important fly control measure in and around farm buildings. Insecticides should be applied in conjunction with a sanitation program because they will not give control under poor sanitary conditions. Eliminate rotting straw and bedding, and spread manure on the fields twice a week. When spraying barns, avoid contaminating feed, water, milking equipment and utensils.
In the following tables, EC = emulsifiable concentrate, and WP = wettable powder.
Table 1. Insecticides for use in dairy barns and other farm buildings
Insecticide	How to use
Dimethoate (Cygon)	A residual-type spray. Gives control up to 6 weeks. Use 1 gallon of a 21.7% EC in 25 gallons of water. Apply as a complete barn spray. Remove animals from buildings before spraying.
Ronnel (Korlan)	A residual spray. Gives control up to 4 weeks. Use 1 gallon of a 24% EC in 25 gallons of water. Apply as a complete barn spray. Adding 5 pounds of sugar in 25 gallons of spray may increase effectiveness.
Diazinon	A residual spray. Use 2 pounds of a 50% WP in 25 gallons of water. Apply as a complete barn spray. Remove animals from buildings before spraying and for 4 hours following application. Sugar may be added as suggested for ronnel.
Synergized pyrethrins	Use as space spray, aerosol or fog for quick knock-down and temporary elimination of flies. Follow directions of manufacturer and/or equipment used to apply it. Especially useful in dairy buildings.
Dichlorvos (DDVP)	Use as mist, fog or spray for quick knock-down and temporary elimination of flies. Has little or no residual effect. Also available as wet and dry baits. Follow label directions.
Trichlorfon (Dipterex)	Use as wet or dry bait, according to label directions. Baits most effective when used as a supplement to sprays.
12-63
Cooperative Extension Work in Agriculture and Home Economics, State of Indiana, Purdue University and U. S. Department of Agriculture Cooperating. H. G. Diesslin, Director, Lafayette, Ind. Issued in furtherance of the Acts of May 8 and June 30, 1914.