European corn borer catches are up from last week at most locations.  Corn earworm are being caught in high enough numbers at a few locations to indicate the need for a four day spray interval.  See the table below for recommended spray intervals based on CEW trap catches.  Fall armyworm was caught in low numbers at just a couple of locations this week.  Western bean cutworm catches are up substantially at a few locations, and catches from the larger WBC trap network indicate that the peak flight will be this week and next week.  Western bean cutworm females are most attracted to late whorl/early tassel stage corn.  They lay masses of 50-200 eggs on the top surface of a leaf near the tassel.  The next few weeks will be important for controlling western bean cutworm in any fields in the attractive stage.

Search tassel-emergence and silk stage fields for western bean cutworm and European corn borer eggs and larvae.  A threshold has not been developed that takes western bean cutworm into account, so count a plant with egg masses or newly hatched larvae as an infested plant the same way you would with European corn borer or fall armyworm, and use a 15% infested plants threshold for tassel emergence stage fields and a 5% threshold for silk stage fields.  As with ECB, it’s important to control western bean cutworm before it enters the ear and is protected from an insecticide application.  See the links to the right for a fact sheet and ID card.