Purdue University
Cooperative Extension Service
West Lafayette, Indiana 47907
Publication E-19
November 1975
Grasshopper Control
David L. Matthew, Extension Entomologist
Many species of grasshoppers occur in Indiana. The most commonly observed species are the large yellow, differential grasshopper, and two smaller ones called migratory and red-legged grasshoppers. All are general feeders. They may attack both natural wild vegetation and cultivated crops. Populations vary from year to year, but generally, grasshoppers cause the most damage in years of high population coupled with dry weather. Drought conditions reduce natural vegetation, forcing the insects to move into cultivated crops.
LIFE CYCLE
Grasshoppers lay eggs in pod-like masses in the soil, either in bare ground or at the base of grass plants. Each egg mass may contain from 20 to nearly 100 eggs. Preferred egg-laying sites are roadsides, ditch banks, fence rows, alfalfa and clover fields, and pastures with thin grass cover. Most grasshoppers overwinter in the egg stage. The eggs hatch during late May through June. The tiny grasshoppers called nymphs may feed for 2 or 3 weeks without being noticed. Then as food becomes scarce or when these early feeding-sites are mowed, the young grasshoppers move to nearby crops or into garden areas. There is one generation each year although a few species may have a partial second generation.
CONTROL MEASURES
Grasshoppers are easiest to control while they are small and still confined to the area where they hatched. Recognition of a potential problem and control in these areas often prevents damage to cultivated crops. in addition, smaller amounts of
insecticides are required and less total area is treated.
Control in Field Crops
Grasshoppers are not difficult to control in field crops with any one of the insecticides listed in Table 1. The pasture, harvest, feeding restrictions and other information in the table will help you select a chemical that meets your particular needs. Mix the amount of material required with enough water to insure even distribution. Repeat applications may be necessary.
Safety
Always refer to the signal word, DANGER, WARNING, or CAUTION on the container label. These words indicate the general use hazard of a pesticide. For example -- PHOSDRIN is highly poisonous to humans if swallowed, inhaled or absorbed through the skin. Thus, the label lists the protective equipment that must be worn when using that material. Follow all label warnings, precautions, and instructions when using any pesticide.
Control in Home Gardens
Most materials, except Phosdrin, listed in Table 1 for farm crop spraying can be used to protect flowers and other non-edible plants. Garden supply stores usually carry these insecticides in small packages for home use. When spraying vegetables, check the label to determine on which crop the insecticide may be used. Spraying garden borders and fence rows will often give effective control.