By Scout Nelson
Nebraska field surveys in 2025 confirm the presence of the soybean tentiform leafminer in 17 counties, highlighting a growing distribution of this native insect. While the discovery shows an expanded range, specialists emphasize that current population levels remain low and pose little threat to soybean production.
“A native insect called soybean tentiform leafminer has been confirmed in 17 Nebraska counties during our 2025 survey (Figure1). Most fields had very low levels, with just a few mined leaves per plant. One hot spot in Dixon County showed heavy edge infestations, but that was the exception.”
Its history shows a slow spread across the Upper Midwest. “This species is native to North America and commonly found on wild legumes, like American hogpeanut and slickseed fuzzybean.
It was first documented on soybean in Minnesota in 2021. Subsequent state detections were South Dakota in 2022, North Dakota in 2023 and a single Nebraska field (Madison County) in 2024. Our Nebraska survey began in 2025 with support from NCSRP.”
Scouting remains the best defense. “Focus on field edges, especially next to dense vegetation such as tree lines. Lift a plant and look at the underside of leaves while slowly rotating the plant. Look for white, blotchy mines — irregular shapes limited to the underside of the leaf surface. Most mines, if present, are typically at or below the mid-canopy.”
Management recommendations remain unchanged. “No insecticide applications are needed based on current levels, time of season, and expected impact. If you suspect leafminer, email a photo and the county in which it was found to Nebraska Extension Entomologist Justin McMechan so we can keep the Nebraska map up to date.”
Experts conclude that Nebraska soybean fields should continue to be scouted, but no new treatments or management changes are required while monitoring continues across the state.
Photo Credit:gettyimages-gilaxia
Categories: Nebraska, Crops, Corn, Soybeans