Alfalfa weevils were produced in unusually large numbers in many alfalfa fields last year. The mild winter meant additional egg laying was likely during warm days and few fall- laid eggs died during the winter. All this has meant an unusually large number of Alfalfa Weevils are in our alfalfa fields this year.
Although weevil damage can be very severe, treatment is not required in all fields even during a heavy weevil damage year. The only sure way to determine if & when a field requires treatment is to sample the weevil population during the time that damage is occurring.
STEM COUNT DECISION METHOD:
Break off 30 to 50 alfalfa stems at ground level, take care not to dislodge the feeding larvae. Select the stems at random from across the field and shake individually into a deep- sided bucket. Count the stems, determine the average height, and count the larvae so the average number of larvae per stem can be calculated.
If your alfalfa condition calls for a spray program go to "Alfalfa Weevil Control" for recommended controls.
Also see: MU XPLOR Guidesheets: Crop Puplications (Forages)