Use of Self-Activating Automatic Spray System in Controlling Face Flies and Horn Flies, 1990

The spray apparatus consisted of a self-contained automatic system with a 30-gal reservoir powered by a 12-volt, battery operated, spray pump. The sprayer was housed in a walkin mineral station mounted on skids to facilitate transport. The mineral box, located at one end of the station, required cattle to walk inside and lift a wooden lid to access the mineral. When a cow lifted the lid over the mineral box and held it open for 10 s or more, 2 spray nozzles above the animal's back were activated for 3 s. As the animal backed out of the sprayer, it was treated with the insecticide mixture contained in the reservoir. For this experiment, a 0.5% water mixture of Vapona feedlot spray was used in the automatic spray system. Before evaluating the automated spray system for horn fly control, horn flies from the experimental herds were tested for resistance against both permethrin and diazinon. The horn fly populations were susceptible to diazinon, but exhibited a 48-fold resistance to permethrin. Prior to treatment and at 2-wk intervals thereafter, horn fly densities were estimated on one side of ten mature animals while face flies were counted on the head and face of these same animals. Untreated cattle within a 1-km radius were used as a control. The test was repeated in two similar herds.