Spider mites, usually 2-spotted, are increasing rapidly on some corn fields in the western Corn Belt now.

Fields that didn’t receive a timely watering earlier in the year have the most mites at this time. Certain insecticide applications for western bean cutworm or applications for other insects earlier in the year also tend to develop mites. Seed corn is particularly vulnerable with the multiple corn earworm treatments that have been applied. Droughty areas and field borders near dusty roads or cedar tree rows also will have more mites.

Bean leaf beetles have increased rapidly in the past 7-10 days on soybeans. Very little pod feeding has occurred so far, but that will change in the next 2 weeks. Treatments need to be applied before significant pod damage occurs. Labels need to be consulted to be sure preharvest intervals are not violated by the various insecticide applications. Mid group II soybeans planted May 1 will be harvested by Sept 10 this year. Pods are beginning to fill rapidly now.

Second generation European corn borers are being monitored closed on the non-Bt corn areas. Moth flights have been rather low at this time, with limited egg laying in many areas. However, the first generation had a late flush of larvae just prior to tassel. There are still pupae in the plants where the moth hasn’t emerged yet. The second generation will continue to be strung out for the next 3-4 weeks.