I’m not overly concerned, but this and last week’s moth traps (see Quick Links) are showing increased numbers of corn earworm and southwestern corn borer moths being caught in pheromone traps.

Corn earworm (bollworm) will not be a substantial crop pest at this time, although we may see some whorl feeding in non-Bt or the original Bt corn technologies.  However, we are certainly catching more than last year at this same time (when it was even hard to catch a moth or find a corn earworm in many corn fields).

The increase in southwestern corn borer (SWCB) moths in some locations indicates the beginning of the first generation.  These moths will lay eggs and feed in the whorls of non-Bt plants.  Bt corn is not susceptible.  In a previous article, I discussed interpreting and and using trapping data.  At this time of year, I would pay special attention to scouting non-Bt corn in areas catching 20 or more moths in a trapping week.  If you have a half hour to kill, consider watching the video linked below that I recorded for the Plant Management Network.  Watch it in bed if you want some shuteye!

Managing for Corn Borers, Emphasizing the Southwestern Corn Borer (video posted on the Plant Management Network, June 2103)