Alfalfa weevil scouting and thresholds

Degree-day information indicates that alfalfa weevil larvae have hatched throughout much of southern Iowa (see map). Proper management of this insect requires timely scouting, correct identification, determination of population levels, and if necessary, cultural or chemical control. Fields should be scouted for alfalfa weevils because the larvae can be very destructive to first cutting alfalfa. They remove leaf tissue, beginning with the new leaves at the top of the plant, and then work down the stem to other leaves. This feeding reduces forage quality and quantity