Remember, if harvest or other action is not taken or is badly timed, yield losses and crop quality losses can occur. After harvest, check stubble and regrowth for signs of weevil feeding. Cost, date until harvest, residue constraints, and weather factors can limit practical implementation of this option. Like harvesting, accurate timing of the insecticide application is necessary for optimal control. Apply when 40 percent of the alfalfa tips show signs of injury from larval feeding.
Precise timing is critical since damage builds up very rapidly.
If spraying is neglected or badly timed, yield losses and crop quality losses can occur. Remember that most insecticides require a waiting period between application and harvest. With frequent observation of each alfalfa field and with proper timing and careful application of insecticide, good alfalfa weevil control can be achieved with the presently labeled and recommended insecticides. For best results, follow these guidelines. Do not treat any field of alfalfa unless it is absolutely necessary to do so as shown by an assessment of feeding damage and weevil populations during the current year.