Grasshopper Control on Pasture, Virginia, 1979

Unimproved fescue pastures near Blackstone, VA were selected to evaluate insecticides for grasshopper control. Test 1 consisted of experimental plots 80 ft long and 45 ft wide established in a randomized complete block design replicated 4 times. Plots and blocks were separated by 5 ft untreated strips. The grass in Test 1 averaged about 6 inches in height at the time of insecticide application. In Test 2 experimental plots, 50 ft wide and 110 ft long, were arranged in a randomized complete block design replicated 5 times. Blocks were separated by 20 ft alleys. The vegetation in Test 2 averaged 1 ft in height at the time of application. Insecticide applications were made to Test 1 on August 13 and to Test 2 on Aug-ust 14. A tractor-mounted boom sprayer equipped with 8004 nozzles was used to deliver 32 gal of finished spray/acre at 30 psi. The grasshopper species com-position before treatment was 80% 3rd and 4th instar Melanoplusdifferentials and 20% other species in Test 1; and 46% M. femurrubrum, 24% M. differentiolis and 30% other species in Test 2. Grasshopper samples were taken before treatment and at 3, 7, and 14 days after treatment using a 15-inch sweep net to make 100-180 sweeps in each plot.