I ended up doing nothing to control the suspected Armyworm infestation of my corn. I read that the life cycle for them is only about a month and if you can wait it out, the corn will be fine. I was skeptical but I waited it out and left them alone.
As you can see, the cornstalks are doing fine, the tassels are doing well, and the ears are growing. I'm as giddy as my 5-year-old. There are no holes on the higher-up leaves, so I guess the adult Armyworms have either died or moved on.