European corn borer catches are mainly down from last week, but they are still being caught at most locations.  Corn earworm catches were more frequent this week, with numbers ranging from 1 to 10 where they are being caught.  Low numbers of fall armyworm were caught at just a couple of sites, and western bean cutworm (WBC) numbers appear to have peaked at some but not all locations.

Where corn earworm are being caught in high enough numbers to drive the spray schedule, the interval will be sufficient to take care of the other worm pests.  Where earworm is low or not being caught, scout tassel emergence stage fields for ECB and WBC eggs and larvae.  Michigan is suggesting a threshold of 4% infested plants for WBC in processing sweet corn and a 1% threshold in fresh market corn.  If no WBC are found use the regular 15% infested plants threshold.  Scout silk stage fields for ECB egg masses and any newly hatched larvae.

Recommended spray intervals based on CEW trap catches