Farmers should scout and, if needed, spray for grasshoppers now, said University of Missouri Extension entomologist Wayne Bailey. Grasshoppers are reported in almost every county in the state, he said.
“Numbers of small grasshoppers are exceedingly high this year in many areas of Missouri and insecticide application may be needed for control,” Bailey said.
Insecticides can kill most small grasshoppers easily. Apply insecticide on borders of fields and crop rows at this time to reduce numbers before grasshoppers move into crop fields.
It is unusual for grasshoppers to be seen this early in the season in soybean fields, Bailey said. Early-season control becomes even more important if predictions for a dry end-of-season come true, he said.
Grasshoppers feed first on grasses and weeds in non-crop areas. When conditions are dry, grasshoppers travel from field borders to crop areas to find more green leaves, Bailey said. They can quickly strip leaves of crops.
Most severe damage occurs after several dry seasons. Cool, wet weather during egg hatch reduces numbers.
More than 100 species exist, but only a few are common in Missouri crops.
Brown, gray or green in color, they grow up to 1 ¾ inches long. They have large hind legs for jumping and prominent heads with large eyes and complex mouth parts. Adults have two pairs of wings and can readily fly or jump when disturbed.
Bailey recommends control methods described on the MU Plant Sciences Integrated Pest Management website at http://ipm.missouri.edu/archive/ipcm/2012/v22n7.pdf.
A free MU Extension guide, “Grasshopper Control in Missouri Forage Crops and Pastures,” is available online at http://extension.missouri.edu/p/G4563.