Grasshoppers often appear first in weedy areas of roadsides, fence rows, irrigation ditches and other noncrop areas. After these food plants are gone, the Insects leave in search of other food, often an irrigated crop or newly emerged winter wheat. Control grasshoppers in the weedy areas with low rates of insecticides. Once they reach field margins, they may be larger and require higher rates of insecticides for control.
Grasshoppers are one of the most important insect pests in Colorado.
They follow a roughly 22-year cycle in Colorado. The last major outbreak was in the late 1970s and early 1980s. Some problems occur even in years of low numbers. Although they are most important on rangeland, they also attack field Crops, often with economic losses to the farmer. An exception is sorghum, which usually is not fed upon once it has reached about 10 inches in height.