What you have is an invasion of armyworms. They are named armyworms for a reason. There are untold millions of them and they will invade and destroy large areas. Here in Texas I have seen them literally denude a large area of all vegetation, grass, trees, weeds, everything. You can easily kill them but by the time you do they have already destroyed everything. I remember as a small boy my dad was growing 20 acres of alfalfa hay and during the period of 2 days and nights everything was gone. Once during my teen years I saw Mother Natures way of dealing with these caterpillars. Birds. Birds of all kinds by the hundreds swooping down and eating them. But waiting for birds may or may not work. It is much easier to get a hose end sprayer and set it to two onces per gallon and spray your ENTIRE PROPERTY with Bt (Bacillus Thuringensis. With any kind of luck maybe your army of armyworms is just a platoon out on a scouting mission and you can save your plants.
