It seems that the abnormally hot and dry summer of 1999 may have led to high numbers of grasshoppers for the year 2000. Weather can affect the size of the population and the amount of damage the insect will do. A female grasshopper can deposit an average of 200 to 300 eggs in her lifetime. Most species deposit eggs in uncultivated fields, waterways, pastures, and roadsides.
Grasshoppers develop through five to six instars.
With adequate food and warm temperatures, a grasshopper can develop into an adult in 35 to 50 days. In southern Illinois, eggs began hatching in the last 7 to 10 days, with most grasshoppers between second and third instar. Treatment may be warranted when there are seven or more grasshoppers per square yard.