I live in N. VA but up on a mtn w/its own micro climate where we are usually 5-10 degrees colder than the surrounding area. I seem to have a problem w/parasitic flies. I found this caterpillar on an A. incarnata this morning and have a couple of ?'s. First, though they continue to flower there isn't much leaf material left on my Asclepias plants. I have a larger number of A. syriaca but do monarchs actually eat this? I also have a fair number of dogbane (Apocynum cannabinum) plants...they are in the same Family as Asclepias but as w/A.syriaca I've never seen monarchs eat it. My second ? is, how do you know if a caterpillar has been parasitized? What would you do?

Thank-you!