By Scout Nelson
Large grasshopper populations are being reported across southeast South Dakota, raising concerns about potential crop damage during the growing season. Recent observations showed that grasshopper numbers in some areas were above recommended levels and that they were actively feeding on crops.
Dry conditions have reduced available food sources, causing many grasshoppers to move from surrounding areas into crop fields. In some cases, heavy infestations can remove large sections of crops, especially the first 100 to 200 feet along field edges. Damage levels depend on the timing of infestation and the grasshopper species present.
Adam Varenhorst, Associate Professor and SDSU Extension Field Crop Entomologist, along with other crop specialists, encourages producers to continue scouting for grasshopper activity. Early detection is important because grasshoppers are easier to control during the nymph stage compared with adult insects.
The USDA recommends managing grasshoppers when populations reach 15 to 20 nymphs or 8 to 14 adults per square yard. Producers should regularly check fields to determine whether grasshopper numbers have reached these levels.
To scout for grasshoppers, producers should walk through fields in a horseshoe pattern. Stops should be made about every 50 feet to count the number of grasshoppers within an estimated one-square-yard-area. This process should continue until the entire field edge has been checked.
If grasshopper populations are above the recommended threshold, applying a foliar insecticide may help reduce crop damage. Producers should select products labeled for grasshopper control and follow current pest management guidelines for proper application.
Monitoring fields regularly allows farmers to identify problems early and make effective management decisions. Grasshopper outbreaks can quickly reduce crop health and yield potential if populations are not controlled.
Photo Credit: pexels-tudsaput-eusawas
Categories: South Dakota, Crops