By Scout Nelson
North Dakota State University Extension reports that the risk of wheat midge infestation remains low heading into the 2026 growing season. Soil surveys conducted across northern North Dakota counties show extremely low levels of overwintering wheat midge larvae, suggesting that farmers may face reduced pest pressure this year.
For the first time since the survey began in 1995, researchers detected zero wheat midge cocoons in fall soil samples. The survey examines overwintering larvae that survive in the soil and later emerge as adult insects during the wheat growing season.
“This is the first time since the inception of the survey in 1995 that zero wheat midge cocoons were found in the fall soil survey for the overwintering cocoons of wheat midge,” says Janet Knodel, North Dakota State University Extension entomologist.
During fall 2025, NDSU Extension county agents collected 1,970 soil samples from 197 wheat fields across 21 counties in northern North Dakota. Each field included 10 soil cores that were analyzed at the NDSU Extension entomology laboratory to determine the presence of wheat midge larvae.
This marks the sixth consecutive year with very low wheat midge populations. Over the past decade, wheat midge numbers have remained well below the economic threshold of 500 larvae per square meter. Dry weather and drought conditions have likely limited the survival and emergence of wheat midge larvae.
Historically, wheat midge caused serious yield and grain quality losses in spring and durum wheat across northern North Dakota during the mid-1990s through 2010.
“The fact that zero wheat midge was detected in the 2025 soil survey indicates low overwintering populations and reduced risk of economic infestation for the upcoming growing season,” says Knodel.
Researchers also note that higher cases of Fusarium head blight in 2025 led some farmers to apply fungicides. In many cases, insecticides were tank mixed with those treatments to control wheat insects such as true armyworm, cereal aphids, grasshoppers, and wheat midge.
“With the low populations of wheat midge for the tenth year in a row,” says Knodel, “scouting for wheat midge is diminished and will be most important in continuous wheat fields.
“However, if localized wheat growing areas receive timely rains prior to heading, wheat midge emergence is favored,” advises Knodel. “On the other hand, if we remain dry, wheat midge mortality increases, and cocoons can remain dormant for several years until soil moisture returns.”
Monitoring efforts also include pheromone traps that help detect early wheat midge activity. In 2025, researchers monitored 23 traps across 19 counties to track insect emergence and guide scouting decisions.
The North Dakota Wheat Commission supports the wheat midge larval soil survey and pheromone trapping program, helping farmers monitor pest risks and improve wheat management strategies.
Photo Credit: gettyimages-ygrek
Categories: North Dakota, Crops, Wheat, Education