Expert weighs in on reader’s question

To the Editor:
I think this is a Monarch Caterpillar, but could anyone tell me what the other things are on the same Milkweed plant?

Monarch caterpillar

Milkweed Tussock moth
Thank you.
Iris Bowers.
From the Editor:  We are fortunate to have an expert in this area and this is what he says …  “The caterpillar is definitely a Monarch.  The other is the Milkweed Tussock Moth. They too feed on milkweeds. They are so numerous that they will defoliate a plant.