Today I visited two fields with large moth numbers (Hwy 45 and White Rd, and Hwy 45 at Knights Landing). On the White Rd field, where the traps caught about 80 armyworm moths per night last week, I found at least one worm in all stops I made (about 10). The worms were small. I did not see any injury. On the Knights Landing field, I found worms in half the stops. These were small worms as well, and I did not see any injury.

I found that the best way to find the worms was to open the canopy, shake the plants vigorously over the water for about 5 seconds, and then look for worms floating in the water. 

I would not recommend a treatment in these fields, since I saw no injury. As these worms grow bigger, they may start feeding on panicles. Keep a close eye, and if you start noticing the typical armyworm panicle injury (broken branches) and the worms are still there, a treatment may be needed.