As temperatures slowly begin to rise, wheat producers should watch for the army cutworm and pale western cutworm; both species can cause economic injury to wheat if populations become large. The army cutworm feeds at night and hides during the daylight hours just below the soil surface.

Scouting for these caterpillars is typically determined by plant injury. Evidence is characterized by a clipped appearance near the base of the plant (as if someone snipped off the stem with a scissors). Often in winter wheat fields, caterpillars will feed on tender blades and avoid the stem and crown (which allow plant regrowth). If large patches of a field appear to be defoliated by these pests, or if 2-4 army cutworms appear per square foot, management is recommended.

Pale western cutworms feed on plants just below the soil surface. They are typically observed later in the spring than the army cutworm and can occasionally be found in winter wheat but are more common in spring wheat. If 1-2 pale western cutworms are observed per square foot, management is recommended. If management is deemed necessary, see the “South Dakota Pest Management Guide” for wheat to determine what course of action is best suited for your operation. For more details on cutworm defoliation and management visit extension.sdstate.edu and search “cutworm”.

Another insect to watch out for this year is the grasshopper. Our SDSU entomology team predicts that grasshoppers are likely to cause issues in areas of South Dakota due to large populations that were present last year and a somewhat late first hard frost date for much of the state. Grasshopper populations are typically worse in dry areas, so the dryer your area, the more potential for issues.

Since spring is among us, another factor to keep in mind is herbicide carryover. Due to dry late summer and fall conditions across many areas, herbicide carryover may be a concern this year. Low moisture, low organic matter, extreme pH, and erodible soils are all contributing factors in herbicide carryover. Carryover is typically worse in areas where sprayer overlapping occurs (headlands) and intensified if spraying occurred late last year. To see a comprehensive list of common herbicides and their rotation restrictions visit extension.sdstate.edu and search “herbicide rotation restriction.”

I wish you a safe and productive spring! Here are some upcoming events and announcements:

Upcoming Extension agronomy events

• May 17: Ag Economic Dialogues — Free webinar to assist farmers and ranchers in making the most profitable decisions for their operations. 10 a.m.
• May 19: Garden Discovery Festival at McCrory Gardens — Come to McCrory Gardens in Brookings for the kickoff of summer programming from 1:30 to 4:30 p.m. CDT. Including tours, presentations, seed swap, and more. Free registration.