Control of Grasshoppers on Rangeland, Three Forks, Montana, August 1976

Three experimental ULV formulations were applied to 10-acre plots in 30-foot swaths with a modified John Blue Low Volume Sprayer (John Blue Company, Huntsville, Al) mounted on a 3/4 ton 4-wheel drive truck. One material, an encapsulated formulations, was diluted 25% with water to insure proper flowage through the pressurized spray system; the other two formulations and the ULV malathion standard were sprayed undiluted. Tests were replicated 4 times. Mortality was determined at 3- and 7-day intervals by counting with a pointer the number of insects in twenty-five 1-yd2 (visual) samples per plot. The species listed above comprised 58, 21, 11, 8, and 2 percent of the infestation, respectively.