Grasshopper Numbers Increasing

June 9, 2000
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. The first instar is very small, about 1/8 inch. 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. Because grasshoppers develop outside crop areas (for example, in roadside ditches), an early insecticide treatment in these noncrop areas can be very cost-effective. A number of different compounds can be used to control these early grasshopper populations (see Table 2).--Mark Hoard

Author: Mark Hoard