Wheat stem sawfly was found in Minnesota fields this year. High numbers of sawfly can cause wheat clipping, making the crop to fall ahead of harvest. University of Minnesota Extension Agronomist Jochum Wiersma says just knowing if fields had sawfly this past year can help farmers prepare for 2020. “If you had fields with a fair amount of stem clipping and lodging, that means there is sawfly overwintering in the crowns currently. The sawfly larvae makes a bomb shelter just above the crown. It’s sitting nice and tight,” explains Wiersma. “Those insects will pop up starting around the end of May.” Farmers can plant special varieties on the outer edge of fields to deal with the pest. “This is a relatively lazy insect. If it finds a suitable host after it hatches, it won’t fly further,” says Wiersma. “We can exploit the edge effect and plant those special varieties within the first 120 feet in adjacent fields. That will hopefully reduce populations over time.”
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