By Scout Nelson
In north central Kansas, dry conditions have intensified the damage caused by alfalfa weevils on the state’s alfalfa crops, according to Kansas State University crop entomologist Jeff Whitworth. "Usually this time of year, alfalfa stems are seven or eight inches long," Whitworth noted. The current drought has stunted growth, with stems only reaching four to five inches.
Whitworth, who routinely scouts Kansas fields for pest activity and treatment effectiveness, observed that fields treated with insecticide two weeks ago are holding up well against the weevils. He highlighted the importance of thorough coverage, stating, "The fields that were treated (with insecticide) two weeks ago seem to be holding pretty well."
In fields yet to be treated, Whitworth predicts the weevils will continue to feed for an additional 7-10 days under the current temperature conditions, which range from 40-70 degrees Fahrenheit. This window is critical for producers, as it represents "hopefully the producer’s last need to use insecticide to control alfalfa weevils."
Once the feeding period ends, the weevil larvae descend into the canopy or ground to form pupal cases, which resemble small cotton balls and offer protection from insecticides. Whitworth also warns of the pea aphid, another pest exacerbated by the dry conditions, which can significantly stress plants by depleting their moisture.
Adding to the pest challenges are army cutworms, which Whitworth mentioned could be affecting some Kansas fields, particularly in wheat. These cutworms feed above ground and are identified by their dusty color. The presence of birds, skunks, and turkeys in a field can indicate an abundance of these pests, as these animals are proficient at hunting the larvae.
As the state battles these agricultural challenges, Whitworth's insights are crucial for farmers aiming to protect their crops from escalating pest pressures amid fluctuating environmental conditions.
Photo Credit -gettyimages-gabrielabertolini
Categories: Kansas, Crops, Alfalfa