Iowa State University degree-day information shows that alfalfa weevil larvae probably hatched in southern Iowa around March 30-31. Weevils should hatch in central Iowa by mid-April and in northern Iowa the last full week in April. Weevil larvae, which remove leaf tissue from new leaves at plant tops and then work down the stem to other leaves, should be scouted beginning at about 200 degree days in fields south of I-80, and 250 degree days north of it. Producers should scout based on projected hatching dates, which are available with degree-day information at www.ipm.iastate.edu/ipm/icm/2007/4-2/alfalfa.html.
Iowa State University degree-day information shows that alfalfa weevil larvae probably hatched in southern Iowa