By Adam Sisson, Corn and Soybean Initiative and Erin Hodgson, Department of Entomology
The alfalfa weevil article published on May 3, 2010 in the ISU Extension Integrated Crop Management News included predicted dates for scouting for the alfalfa weevil larvae in Iowa. The article used degree days that were obtained from the web-based climate service Midwestern Regional Climate Center.
Following publication of the article, Iowa State University Extension field agronomist Brian Lang noticed that the degree days reported in the article were lower than what he was observing in northeastern Iowa and that degree days reported by ISU Extension field agronomist Virgil Schmitt for the east-central and southeast parts of the state were higher than reported in the article.
The information from Iowa State Extension field agronomists and new data from a cumulative growing degree day map from Oregon State University suggest that all of the crop reporting districts in Iowa have surpassed the scouting threshold for alfalfa weevil and that growers should presently be looking for the insect in fields.
We apologize for any confusion.
Adam Sisson is a program assistant with responsibilities with the Corn and Soybean Initiative. Sisson can be contacted by email at firstname.lastname@example.org or by calling (515) 294-5899. Erin Hodgson is an assistant professor of entomology with extension and research responsibilities. She can be contacted by email at email@example.com or phone (515) 294-2847.