Not an armyworm and not a Noctuid, but a fairly common pest of deciduous trees...the Yellow Necked caterpillar, Datana ministra (Notodontidae). At first, I thought it to be Drexel's Datana, and I probably shouldn't rule that out. Apples are definitely a host, but you can find these larvae on oaks, pecans, hickories, and others. I see that your orchard is surrounded by a woodland with mixed tree species. I'll wager that some of those trees are being defoliated, too. I strongly suggest that you make a careful inspection of your other trees now. These caterpillars start out as very small insects, and are much easier to control with the biological Bt-K at that time. Next year (and they will be back...the caterpillars pupate in the ground and emerge in the spring), look for the white egg masses on the leaves and remove them. I'm pretty certain that the moths lay their eggs on the lower surface of the leaves. Get rid of those and you'll be home free. Birds love these caterpillars, by the way. Hopefully the word will get out through the robin, bluejay, cardinal, etc. clans.

Yeah, I thought it was probably a moth, but it didn't feel right to go to the pest forum because this one's a pet, not a pest (there's a fine line, isn't there?) and I didn't know where else to go. I was about to cross-post there anyway just now, but I think my caterpillar is pupating already. Guess I'll find out what kind of moth it is soon enough!

I prefer the picking and stomping method myself. :)) I have several tomato plants as well as hot pepper plants in the ground. I've yet to see one bug on any of them. For some reason they all prefer my brugs. The brugs seem to be the attractant plants. Especially the varigated brugs, altho they leave many of the other varieties alone. Altho I've had the suckers on my brugmansias in the past, this year seems to be the worst. Half my brugs I now call my 'lace plants'. I can't keep up with finding them all. In our old gardens I used to grow Nicotianas which were the attractant plant of choice. Altho I've read that you aren't supposed to grow them near tomatoes (same family), I did by accident and by accident I realized that the worms were attracted to them. I never had one tomato worm on my vegies and they loved the Nicotianas. From that year on I always grew them near the vegies and it worked like a charm. I think I'm going to have either try to find my saved seed for the Nicotianas or buy more for next year and see if they work as well with the brugs as they did with the tomatoes, peppers, cucs, etc. Jenna

Here you go! Here is a link that might be useful: What Is This Caterpillar?