During the past week many alfalfa fields have required insecticide applications for control of alfalfa weevil larvae. Foliar feeding damage from alfalfa weevil is moving northward as additional eggs hatch and larvae grow in size. The bulk of damage should occur in central and northern Missouri regions within the next 2-3 weeks. In southern Missouri producers should continue to scout fields for this pest as a second wave of larvae may yet develop. Zoophthora phytonomi , the pathogenic fungus which can cause the rapid collapse of the weevil larval populations, may still occur this season. This fungus will most likely occur in those areas of the state where wet conditions persist for several days. Larvae infected with the fungus will turn from green to light yellow in color and die within 2- 3 days. See the previous newsletter for non-chemical and insecticidal management recommendations.

Wayne Bailey
573-882-2838
573-864-9905